Making HIIT a Hit Part I/II: The Quest for the Optimal Interval to Rest Ratio for Your Type & Goals - Warming up: Selected Studies + Individual Take Home Messages to Set the Scene

This series will not readdress the "HIIT and/or LISS debate", but simply try to do what the title says: Help you to determine the "ideal" form of HIIT for your type & goals.

After posting yet another article about the benefits of high intensity interval training (HIIT) training on Wednesday, I thought it may be a good idea to take a look at the pertinent literature to get a better grasp of what exactly high intensity interval training actually is... "What it is? What do you mean?" While almost everyone appears to recommend you do at least some amount of high intensity interval training, these days, the definition of both the "high intensity" and the "intervals" which are more than just eponymous of this type of training are usually pretty wooly. The two questions this article is supposed to answer are therefore: How long should the intervals and rest periods be and at which intensity should they be performed.

Attention, this article turned into a two part series: I must warn you, this "quest" turned out to be hell lot of work and way more than I had expected. So I will have to split it up into a two-part series. With today's first part discussing exemplary "success stories" and the subsequent follow up on next Sunday providing a more comprehensive overview and general conclusions one may draw based on the picture that emerges.

Part I: Success stories - learning from the "best"

I decided that it may be a good idea to initially compile some examples of which you could say that they are examples of a successfully implementation of high intensity interval training. In that, I will put an emphasis on "old" studies that have not yet been discussed on the SuppVersity. This means, if you want more examples before next week's 2nd installment with a more general overview, you can simply click through the archive of articles that are marked with the keyword HIIT - either as HTML or RSS (I recommend the latter if you do not intend to read all of them anyway; opens in all good browsers without a reader).

Untrained participants and non-athletes

• 5min on, 2min off HIIT to increase fitness (VO2max) alternated with 40 min steady state cardio for 4 + 5 weeks (Hickson. 1981) -- Hard to believe but it's more than 30(!) years ago that Hickson, Hagberg and Ehsani were able to show that a combination of high intensity interval training with 6x5min cycling at 90-100% of the VO2max and 2-min at 30%-50% active rest between intervals on day one and 40 min of steady state "cardio" on a treadmill on day 2 (6 workouts per week) yielded profound increases in VO2max:
  

  

  Figure 1: Adaptation to combined HIIT + steady state protocol in "occasionally active" but not "regularly" trained men (n=8) and women (n=1) in the Hickson study (Hickson. 1982).

  For our purpose, the most significant finding of this study may however be that the t_1/2, i.e. the amount of time it takes for 50% of the adaptations to take place is only 10 days (on this intense protocol).
  
  Take home message: If VO2Max and overall conditioning is your goal you should up the intensity every three weeks, to make sure you continue to make progress. If you go by VO2max, this would be an increase in the speed you run or bike - not (!) the duration of the intervals and / or their number.

• 2 series of 5s sprint cycling (8-13x) with 55s of active rest increase force production and rids subjects of "useless" type IIb fibers (Linossier. 1993) -- The 10 students (8 men, 2 women; age 22y; VO2max = 51.2ml/kg/min, everything below 55 is still considered ) in the Linossier study performed 4 HIIT only workouts consisting of 5s all-out sprints on a cycle ergometer interspersed by 55s of active rest cycling at a heart rate of 130-140bpm per week. The number of sprints in each of the two sessions on a single training day (15 min of rest between) were increased from 8 to 13 sprints over the 7-week study period. The main results were improvements in both peak performances +25%  and in the 30-s total work +16%.
  
  

  

  Figure 2: Unexpected shift in muscle fiber type distribution (Linossier. 1993)

  What's also relevant, though not directly performance related is the 19% increase in phosphofructokinase and a 20% increase in lactate dehydrogenase, both are glycolytic enzymes and are indicative of improvements in the glycolytic pathway, which goes to show you that you don't have to be afraid of the fiber type changes hampering either your ability to handle glucose or your strength - I mean +29% in maximal force production in the sprint tests are everything else but "weak".
  
  Take home message: Shorter sprints appear to be a valid means to hammer and improve the glycolytic pathway and get rid of the useless type IIb fibers, of which not endurance athletes, but bodybuilders have the lowest amount and sedentary controls the most (cf. figure 1 in the overview of the Intermittent Thoughts on Building Muscle). To actually build muscle the 1% increase in muscle weight the scientists observed, is yet not sufficient enough.

• 7 sessions of 10x4 min cycling at 90% with 2 min rest ramp up skeletal muscle fat metabolism in young women (Talanian. 2006) -- The 8 healthy recreationally active women (22 yr old, 65.0 kg body wt) who had previously engaged in 2-3 just-for-fun sessions of various activities from weight lifting, soccer and cycling to swimming, or walking, participated in no more than 7 HIIT sessions within 2 weeks (1 day on, 1 day off) which consisted of 10x 4min sprints at 90% of their individual VO2max with two minutes of rest in between.
  
  

  

  Figure 3. Changes in substrate utilization during standardized 60 min LISS test at 60% of the VO2Max (Talanian. 2006)

  Contrary to the previously discussed studies, the scientists were in this case less interested in the performance than in the metabolic benefits, which were - as the data in figure 1 show - surprisingly significant given the short duration of the study. The increases in fat oxidation and decreases in the respiratory ratio (the ratio of glucose to fatty acid oxidation) during a standardized 60min light intensity (60% VO2max) test that was performed at the beginning and end of the study, were a consequence of increases in citrate synthase and beta-hydroxyacyl-CoA dehydrogenase (beta -HAD) activity.
  
  Take home message: In view of the important contribution of beta-HAD to the beta oxidation of (esp. medium-chain) fatty acids, the fact that an upregulation of this enzyme has been observed in response to the long duration intervals, but neither light intensitsy exercise (even w/ 2h per day, 5-6 times per week; cf. Phillipps. 1996), nor during a similar 2-week sprint training protocol (30s all-out on cycle ergometer, 4 min rest; cf. Burgomaster. 2005) points towards "long" duration intervals when mitochondrial adaptations that favor fatty oxidation and thus subsequent increases in fat loss with light activity are concerned. 

Highly trained participants and pro-athletes
 

• 3 sessions of 10 intervals at 96% VO2Max with 60-180s rest increase running economy and relative fatty oxidation during subsequent steady state exercise test (Zavorsky. 1998) -- Twelve highly trained endurance athletes volunteered for this study, four of them qualified for the 1996 Canadian Olympic Trials, and one subject was a Canadian record holder in triathlon. On three different occasions the subject ran 10 x 400-m sprints with active recovery periods of 60, 120, 180s (randomly assigned). 10 min before and afterwards standardized running economy tests were performed.
  
  

  

  Figure 4: Respiratory exchange ratio in RE test before and after the sprinting protocol (Zavorsky. 1998)

  During these running economy tests, which consisted of 2 x 5 min running on a treadmill at 12km/h or 16km/h (5 min total rest in between), the subjects exhibited, much contrary to the research hypothesis, by the way, an increase in the running economy (RE, a measure of how efficiently a person uses oxygen while running at a given pace) and - probably of greater interest for most of you an increase in fatty acid oxidation, as evidenced by the reduced respiratory exchange ratio (RER, figure 4). The latter was particularly pronounced in the "low intensity" RE test at 12km/h.
  
  As far as the differential effects of the rest intervals is concerned, significant effects were observed for the rates of perceived exertion (60s: 17.7; 120s: 16.1; 180s: 14.4), but not for the performance related measurements velocity, and the time it took the athletes to run the 400m sprints (actually the latter should be self-evident with identical velocities).
  
  Take home message: Doing ten short sprints (if you are not an athlete, shorter ones will suffice) before you go jogging (or do any other type of steady state cardio) won't hamper your running economy. And since the study at hand suggests that the relative increase in fatty acid oxidation is specifically pronounced in the lower intensities (this is supposedly even more the case if you jog at 10km/h), the combination of sprints + steady state cardio appears to be an ideal "cardio" only day, when you are trying to lose body fat.

• 8x all-out (100% VO2max) 2.5min intervals with 4 min of active rest increase VO2Max, peak aerobic power and 5k time trial performance regardless rest between sessions (Gross. 2007) -- With the unique twist with respect to the training frequency this study is somewhat unique. While other studies report similar benefits in highly trained collegiate cyclists (13 men, 4 women; VO2Max at baseline 62ml/kg/min) or other endurance athletes, this is one of the few that investigates whether it makes a difference if the athletes implement the 3-days per week HIIT regimen as a block or interspersed by one day of rest into their regimen.
  
  

  

  Percent change in TT5k velocitym TT5k power output VO2peak, and peak aerobic power output in cyclists trainin on consecutive vs. non-consecutive days (Gross. 2007)

  Interestingly enough, neither the performance outcome on the pre- and post tests, i.e. increases in VO2Max (+5.7%), peak aerobic power (+7.2%), 5k time trial performance (+6.9%), nor the actual performance during each of the workouts the subjects performed in the course of the 3-week study period suffered from doing the HIIT sessions back to back. These results refute previous speculations that doing HIIT as a block would trigger greater metabolic adaptations, specifically in athletes (e.g. Padilla. 2000). Even more, though the changes were not statistically significant, the data in figure 5 shows that - with one for endurance athletes important exception, namely the VO2Max - training on non-consecutive days produced marginally better results.
  
  Take home message: While it appears as if it would not make a difference whether you perform your HIIT workouts blocked or within your training week. The non-significant differences in figure 5 could suggest that endurance athletes intending to improve their already high VO2Max even further would be better off with the blocked training. Everybody else has the choice and I would pick the interspersed variety, whenever my schedule allows me to do this - my personal experience told me that this works better for me... apropos, take another look at figure 5 you see the narrow bars indicating the standard deviations? This goes to tell you that it is very likely that not just the personal preferences, but also the actual outcome will vary from trainee to trainee, which supports the notion that you will have to experiment to find what works best for you.

That's it for the "success stories"! Don't forget to come back next Sunday for part II and in case you have not done so already, just browse the previous SuppVersity posts on this matter, either as HTML version, post by post, or from the RSS overview (works in every modern browser, yet not in Google spyware ;-). I know you are smart enough to draw your own conclusions. And what's more, this may yield some cognitive input for the comment area of this article, where you can post questions. I will try to tackle those I can answer in the next installment.

References:

• Burgomaster KA, Hughes SC, Heigenhauser GJF, Bradwell SN, Gibala MJ. Six sessions of sprint interval training increase muscle oxidative potential and cycle endurance capacity in humans. J Appl Physiol. 2005; 98: 1985–1990.  
• Gross M, Swensen T, King D. Nonconsecutive- versus consecutive-day high-intensity interval training in cyclists. Med Sci Sports Exerc. 2007 Sep;39(9):1666-71.
• Hickson RC, Hagberg JM, Ehsani AA, et al. Time course of the adaptive responses of aerobic power and heart rate to training. Med Sci Sports Exerc 1981; 13: 17-20.
• Linossier MT, Denis C, Dormois D, Geyssant A, Lacour JR. Ergometric and metabolic adaptation to a 5-s sprint training programme. Eur J Appl Physiol Occup Physiol. 1993;67(5):408-14. 
• Padilla S, Mujika I, Orbañanos J, Angulo F. Exercise intensity during competition time trials in professional road cycling. Med Sci Sports Exerc. 2000 Apr;32(4):850-6.
• Phillips SM, Green HJ, Tarnopolsky MA, Heigenhauser GJ, Grant SM. Progressive effect of endurance training on metabolic adaptations in working skeletal muscle. Am J Physiol Endocrinol Metab. 1996: 270: E265– E272, 1996
• Talanian JL, Galloway SD, Heigenhauser GJ, Bonen A, Spriet LL. Two weeks of high-intensity aerobic interval training increases the capacity for fat oxidation during exercise in women. J Appl Physiol. 2007 Apr;102(4):1439-47. 
• Zavorsky GS, Montgomery DL, Pearsall DJ. Effect of intense interval workouts on running economy using three recovery durations. Eur J Appl Physiol. 1998; 77: 224-30.

Bigger, Stronger, Faster: CoQ10 for Brain & Muscle in Young & Old. The Optimal HIIT Regimen for Fun & Fat Loss - 8s at 100% 60s Idling! Protein Power From Oats? Plus: Rest Times, Clusters, Form & Hypertrophy Training

I decided against calling this the "Get Big, Green and Look Like the Hulk Quickie" (img. Paramount Pictures)

In view of the fact that most of you apparently enjoyed the "Get Lean and Stay Lean Quickies" I posted in the last weeks, I thought you may also be inclined to read a "Get Big, Green and Look Like the Hulk Quickie", but then decided that the name was too long for the headline and "big, green" and maybe even "hulk" in conjunction with "quickie" may have had the SuppVersity turn up on google and other search engines in too close vicinity to websites I do not exactly want this blog to be associated with (just kiddin' ;-)

Be that as it may, enjoy the ride and let me know whether you do prefer this thematically structured approach over the classic news-potpouris ala On Short Notice.

I mean you can obviously argue in favor of both and since this is a place I want you to look forward to visit everyday, I would be inclined to hear whether "innovations" like this make it better or worse.

• CoQ10 supplementations could offer beneficial effects on brain and muscle in elderly individuals and could - at higher doses - work for youngsters, as well (Shetty. 2013) -- In a rodent trial the provision of a relatively high dose of CoQ10 as part of the diet effectively blunted age-induced 'cognitive decline' (whatever that may be in a mouse ;-) and protein breakdown in heart, liver and muscle tissue of the 17.5 months-old mice.
  
  

  

  Figure 1: Carbonyl levels in liver and muscle of young and old mice.

  This result is also interesting, because the mitochondrial protein breakdown in the brain was the one which was least beneficially affected. What's of greater importance, for this news quickie at least, is that the 2.81mg CoQ10 per gram of chow the high dose group received (the human equivalent would be roughly 33mg/kg or 2-3g per day!) elicited beneficial effects on the skeletal muscle carbonyl content, a marker of protein oxidation, in the young animals, as well (see figure 1).
  
  The notion that coQ10 in appropriate doses could be beneficial not just for statin users, but also for perfectly healthy people, even athletes, is also supported by the beneficial effects the administration of coQ10 had in a recent trial where it blunted the oxidative damage due to a high frequency endurance training program in rodents (Okudan. 2013). It does however stand in contrasts with a recent study by Bloomer et al., n which the supplementation of only 300mg (ca. 15% of the HED used in the study at hand) did not yield the desired effects on the exercise performance of 15 perviously individuals (10 men and 5 women; 30-65 years; Bloomer. 2013). Whether this really is just a matter of the correct dosing, or maybe a fundamental difference between mice and men will still have to be elucidated and I would not spent the bucks for anything that's only "maybe" going to work.
• Rats don't do well with hypertrophy training (Scheffer. 2013) -- According to a recently published paper by Scheffer et al., rodents who are afraid of increases in markers of oxidation should refrain from hypertrophy oriented muscle training and stick to lower volume resistance training.
  
  For their study, the Brazilian researchers had analyzed the effects of three different resistance training protocols, namely  muscular resistance training (RT), hypertrophy training (HT), and strength training (ST), which had to be performed twice a week for 12 weeks on muscle lactate and glycogen content, superoxide production, antioxidant enzyme content, and activities, as well as markers of lipid and protein oxidation.
  

  

  While you certainly don't want a fire inferno, doing too little is not going to yield the results you are looking for either (suggested read "The emerging role of an auto-/endocrine-immune axes")

  "Results showed increased superoxide production (UT = 5.348; RT = 5.117; HT = 8.412 ; ST = 6.354), SOD (UT = 0.078 ; RT = 0.101 ± 0.013; HT = 0.533 ± 0.109; ST = 0.388), GPx (UT = 0.290; RT = 0.348; HT = 0.529; ST = 0.384) activities, and content of GPx (HT = 3.8 times; ST = 3.0 times) compared with the UT group. CAT activity was lower (UT = 3.966; RT = 3.47; HT = 2.276 ; ST = 2.028) in HT and ST groups. Oxidative damage was observed in the HT group (TBARS = 0.082; carbonyl = 0.73; thiol = 12.78) compared with the UT group.

  The way in which the authors' conclusion that these "findings indicate that HT causes an imbalance in oxidative parameters in favor of pro-oxidants, causing oxidative stress in skeletal muscle" does implicitly suggest that this is a bad thing that has to be avoided at all cost, which is obviously totally beside the point - if you don't challenge your body he has nothing to adapt to and neither your conditioning, nor your strength or muscle mass are going to improve. The absence of statistically significant increases in oxidative damage in the low volume strength training routines, on the other hand supports the notion that you can use phases of very low volume training with heavy weights in between intense phases of overreaching to monetize on the muscular gains (which will probably keep coming in these 2-4 weeks) by taking all your lifts to another level and thus lying the foundation for future growth.
• Optimized HIIT regimen for overweight kids: 4s max sprinting + 60s active recovery do the trick - could work four you, as well! (Crisp. 2013) -- Either from the SuppVersity news or from listening to Super Human Radio you may remember that a recent study by Deighton et al. has found that sprinting will increase your appetite more and burn less calories than workload matched steady state cardio training. A novel study from Australia does now suggest that this may well be the case, but probably only as a result of doing it wrong - the sprinting, I mean.
  
  
  In their study Nicole A. Crisp and her colleagues from the School of Sport Science at the The University of Western Australia, describe how the combination of 8s all-out sprints on a cycle-ergometer with 60s of active rest easily outperforms its 30min steady state counterpart (30min moderate pace) and its "little brother" and "big" bother the 8s sprint, 120s active rest and the 8s sprint, 30s active rest protocol, respectively.
  
  

  

  This is not the first study to show the superiority of HIIT training in obese boys. In February 2013, I have already covered a very similar study where a brief HIIT session that burns "only" 360kcal was a major motor to teenage weight loos.

  In that, it's important to note that despite a linear increase in energy expenditure from the 60s to the 30s rest group, the latter failed to reach statistical significance (p = 0.076), ...
  

  "[...] likely as a result of decreased sprint quality as indicated by a significant decline in peak power output from SI₆₀ to SI₃₀ (p = 0.034)" (Crisp. 2013)

  In conjunction with the absence of the overcompensation effect at the following breakfast buffet (which was present in the 8/30s and to a lesser degree even the 30min steady state trial), this makes the 8/60s protocol the superior choice for everyone doing HIIT mainly to get or stay lean.
  
  And aside from its practical value, the 8/60s regimen was also the one the boys enjoyed the most.
  
  "And what about me?" I don't see why doing this very short sprints with large bouts of active recovery in between would not be right for you, as well. At least if the activation of your metabolism and / or fat loss during a diet is your primary goal and not an improvement in VO2 max., you would thus probably get many of the benefits at a smaller risk of overtraining. Just make sure you are actually sprinting all-out for the whole 8s and don't stop, when you are just about to get up to speed ;-)
• Long rest times necessary for high jumpers - with 8-12 min pause your performance on the next jump will increase not decrease (Gouvêa . 2013) -- In a recent meta-analysis that's soon going to be published in the Journal of Sports Sciences André Luiz Gouvêa and his co-workers report that the manipulation of rest intervals seems to affect post-activation potentiation magnitude and jump height.
  
  After analyzing fourteen studies, which met the criteria of having a crossover design, being randomised, or non-randomised and counterbalanced and observed the voluntary muscle action-induced post-activation potentiation on jumping performance, the scientists state that the...
  

  "[...]results demonstrated medium effect sizes for rest intervals 0–3 and 8–12 min (-0.25 for 0–3 min; 0.24 for 8–12 min) and a small effect for other ranges (0.15, CI: -0.08 to 0.38 for 4–7 min; for ≥16 min)." (Gouvêa . 2013)

  Since there was little to no evidence for heterogeneity among the sub-groups and no indication of publication bias, these results clearly suggest that rest intervals of 0–3 min have detrimental, rest intervals between 4-8 min neutral and rest intervals of 8-12 min beneficial impact on jump height. In that, the improvements are likely to be mediated by post-activation potentiation.
• The science of cluster training - Conventional wisdom prevails, 10 deep breaths would yield optimal rest time between reps (Hardee. 2013) -- At lest with respect to proper form, which may also have consequences for optimal muscle recruitment and hypertrophy, the optimal rest time between two reps in a cluster appears to be 20s, which is actually what the good old "10 deep breaths rule" would state, as well.
  
  
  What is a cluster? When you are "clustering" your sets you are doing one (sometimes also 2-3) rep(s), rack the weight, rest, do another rep etc. This is a very good technique to increase your strength and break through plateaus that's useful for powerlifters and bodybuilders alike.
  In order to examine the effects of three different cluster set configurations on power clean technique, the scientists recruited 10 male, recreational weightlifters who had to perform clustered or non-clustered power-cleasn: 3 sets of 6 repetitions at 80% of their individual repetition max with 0 (P0), 20 (P20) or 40 seconds (P40) inter-repetition rest.
  
  In the P0 (no cluster) condition, the scientists observed how the form suffered and got worse and worse from the first to the last rep (the catch and first pull were in a more forward position during repetition 6 as compared to repetition 1). With the long rest times in the P40 condition, on the other hand,  "differences in horizontal displacement were found between repetitions 1 and 6 for the second pull and the loop" (Hardee. 2013).
  
  In the P20 condition the researchers did not observe any differences in horizontal displacement between repetitions 1 and 6 during P20. Reason enough for the scientists to conclude that their results would demonstrate that cluster sets with greater tha 20s of inter-repetition rest would be useful to maintain appropriate form without significantly dropping the density of your workout - whether this did actually facilitate strength or size gains was yet not evaluated in the study.
  
  The evidence for the efficacy of this training regimen (aside from simply providing a novel stimulus, which is obviously always a good thing) does come from a 2011 study by  Hansen et al who compared the response of highly trained rugby players to on traditional vs. clustered leg training program and found the latter to be slightly superior with respect to the increase in peak velocity and strength , while the classic continouus set training had an edge as far as total power increases in the lower limbs were concerned (Hansen. 2011).
• Oats healthy car source with performance protein? (Xu. 2013) Who would have thought that, oats are not just an excellent source of slow digesting carbs and potentially fat-burning beta glucan (listen to the SuppVersity Science Round-Up from two weeks ago), they also contain a non-negligible amount of protein of which researchers from the College of Food Science and Engineering at the Northwest A&F University in Yangling, China, have now shown that it ameliorates the increase in lipid oxidation (MDA) and decrease in antioxidant activity (SOD) during an exaustive bout of swimming in 30 male mice.
  
  After the oat protein had been purified from oat meal thirty male Kun-ming mice were divided kept on either a normal control diet, a diet that was enriched with oatmeal and a diet that contained only the protein fraction of the oats. After 20 days, the rodents were subjected to swim to exhaustion. Their swimming endurance and the major metabolic substrates were measured from serum, liver and muscle.
  

  

  Figure 2: Antioxidant enzymes up, lipid oxidation down. That's the result of a comparison of the detrimental effects of an exhaustive swimming test in mice fed regular, oat enriched or oat protein pimped diets for 30 days (Xu. 2013). What the study cannot answer is however whether identical effects would have been seen w/ any other high quality protein as.

  "The results showed that no significant differences were observed in swimming endurance test between the normal control group and the oat protein group (P > 0.05). Mice in the oat meal group had significantly longer swimming endurance compared to the normal control group (P < 0.05). Furthermore, dietary oat protein increased the levels of liver glycogen, enhanced the activities of lactic dehydrogenase and superoxide dismutase, and decreased the levels of blood urea nitrogen and malondialdehyde in serum." (Xu. 2013)

  Now the good news certainly is that id did work. The "bad" or at least not so good news, on the other hand is that there is no adequate control group, since the addition of both the oats and the oat protein will have increased the amount of essential amino acids in the rodent chow significantly.

That's it! At least as far as news on getting bigger, stronger and faster is concerned. In case yo are also interested in something else, for example...

• how scientists have successfully transformed former breast cancer cells back to benign mammary epithelial cells by placing them in a non-carcinogenic environment like a healthy non-inflamed mouse
• that continously taking 25,000IU of supplemental vitamin A is at least not particularly healthy for young lean and obese women
• why Munuka honey, when Greek or Cypriot Honeys are the more potent antimicrobials?

and whatever else I will still be posting before tomorrow's SuppVersity news, you are alway welcome to visit the SuppVersity Facebook Wall.

References:

• Bloomer RJ, Canale RE, McCarthy CG, Farney TM. Impact of oral ubiquinol on blood oxidative stress and exercise performance. Oxid Med Cell Longev. 2013;2013:465020. doi: 10.1155/2013/465020. Epub 2013 Aug 23. 
• Crisp NA, Fournier PA, Licari MK, Braham R, Guelfi KJ. Optimising sprint interval exercise to maximise energy expenditure and enjoyment in overweight boys. Applied Physiology, Nutrition, and Metabolism, 10.1139/h2013-111. 
• Gouvêa AL, Fernandes IA, César EP, Silva WA, Gomes PS. The effects of rest intervals on jumping performance: A meta-analysis on post-activation potentiation studies. J Sports Sci. 2013 Nov 9.
• Hansen KT, Cronin JB, Pickering SL, Newton MJ. Does cluster loading enhance lower body power development in preseason preparation of elite rugby union players? J Strength Cond Res. 2011 Aug;25(8):2118-26.
• Hardee JP, Lawrence MM, Zwetsloot KA, Triplett NT, Utter AC, McBride JM. Effect of cluster set configurations on power clean technique. J Sports Sci. 2013 Nov 5.
• Okudan N, Revan S, Balci SS, Belviranli M, Pepe H, Gökbel H. Effects of CoQ10 supplementation and swimming training on exhaustive exercise-induced oxidative stress in rat heart. Bratisl Lek Listy. 2013;113(7):393-9. 
• Scheffer DL, Silva LA, Tromm CB, da Rosa GL, Silveira PCL, de Souza CT, Latini A, Pinho RA. Impact of different resistance training protocols on muscular oxidative stress parameters. Applied Physiology, Nutrition, and Metabolism, 10.1139/h2013-115
• Shetty RA, Forster MJ, Sumien N. Coenzyme Q(10) supplementation reverses age-related impairments in spatial learning and lowers protein oxidation. Age (Dordr). 2013 Nov 10. 
• Xu C, Lv J, You S, Zhao Q, Chen X, Hu X. Supplementation with oat protein ameliorates exercise-induced fatigue in mice. Food Funct. 2013 Nov 12.

Cardio & Weights - Mutual Exclusives or Synergists? Two New Studies Suggest: Cardio "Before" and After Workouts Offers More Benefits Than Downsides for Strength & Mass

Could "cardio" really be more than just a necessary evil on your way to a physique like this?

Yesterday testosterone booster (see "Capsaicin or 28-OB...") and today already the next "bro favorite": The never ending debate about "cardio and weights" (or should I rather write "cardio vs. weights"). If you are no newcomer to the SuppVersity you will be aware that this is not the first time, we are tackling this issue (e.g. "Cardio Before or After Weights?" or "Before, After or In-Between"). While most of the previous posts did however deal with the question of "How do I do the least damage to my resistance training, if I want to do cardio, as well". The two studies, I have in stock for you, today, would suggest that this question in and out of itself is quite nonsensical and that the "correct", or at least way more productive question must be: "How can I use cardio to promote my strength and mass gains?"

Curious? All right, let's take a look at what Tufano, Lundberg and their respective coworkers have in stock for you (Tufano. 2013; Lundberg. 2013)

• The Tufano study confirms that doing cardio after an intense leg workout facilitates recovery- A question yet remains: What are the long term consequences? At least as long as you stick to doing just 20 minutes of cardio at 70% of your maximal heart rate, some cycling after a an eccentric leg workout (6 sets of 10 reps of eccentric leg extensions, specifically designed to induce maximal DOMS).
  
  

  

  Figure 1: Isometric strength after eccentric leg extensions in no, low and mean intensity cycling group expressed relative to pre values (Tufano. 2013).

  In the most recent study from the Department of Kinesiology at the Center for Sport Performance of the California State University the 10 women in the medium intensity cycling arm, who had cycled for 20 minutes at 70% of their individual heart rate recovered faster the muscle damaging workout than the women who went home without a "heavy cool down". What's actually even more astonishingly, though is that they also recovered faster than a third group of women who performed the 20min workout at only 30% of their VO2max.
  
  While there were no differences in pain scale or dynamic strength during the 4-day recovery phase, the isometric strength of the women in the 20min @ 70%VO2max arm of the study showed significant super-compensation effects on day 3 and day 4, so that Tufano et al. conclude:
  

  "Enhanced blood perfusion during moderate-intensity aerobic recovery, in conjunction with a short-term training effect, may enhance isometric strength after DOMS. Therefore, moderate intensity aerobic activity is suggested as a recovery method after multiple eccentric muscular actions." (my emphasis in Tufano. 2013)

  That certainly sounds as if another bro-scientific myth was tumbling and about to fall. Still, Tufano et al. are also right to point in the discussion of their results, that we need further research into the chronic effects of moderate-intensity aerobic 'recovery exercise' after resistance training - I mean, who guarantees that doing this after every workout week after week, month after month won't eventally turn against you?

What? You are not interested in recovery, anyway? All you want is grow and you doubt that the small increase is indicative of earlier supercompensation and that strength and grows would be two different pairs of shoes, anyway? Well, in that case here is another pro-cardio study:

• 

  The first important question this study answers is: How do you cycle with just one leg. You see the answer in the small inset of the image above.

  Aerobic before resistance training leads to minor increase in mTOR response and does not seem to hinder muscle gains! This one certainly flies in the face of what you may have been told by credible and less credible experts for your whole life. I mean, if anything, cardio was supposed to keep the gains lean. While the consensus is that it will diminish your gains -- right? Well, according to the latest study from the Mid Sweden University and the venerable Karolinska Institute and University Hospital in Stockholm this could turn out to be just another counterproductive bro-scientific myth: Skipping cardio altogether is not simply bad for your overall health an conditioning, as it would seem, it could even be beneficial for your gains, as well.
  
  To probe the effects of aerobic training on a whole host of hypetrophy and performance related factors, Tommy R. Lundberg and his colleagues recruited 9 physically active men (23+/-1 yr, 18+/-6 cm, and 75+/-6 kg) who "had been involved in recreational aerobic exercise two to three times per
  week and/or habitual RE one to two times per week for more than a year" (Lundberg. 2013) and had them perform a 45-min one-legged cycle ergometry exercise
  

  "The target load was 70% of the Wmax (cadence = 60 rpm). After 40 min, workload was in-creased by +20 W, and subjects were requested to continue until failure to maintain the prescribed cranking cadence, which typically occurred within 1–4 min (2 min 43 s)" (Lundberg. 2013)

  that was followed by 14 maximal concentric–eccentric knee extensions for each leg 6 h later (2 sets, 7 reps, 90s rest; starting with the AE+RE leg).
  

  "Thus, one limb was subjected to aerobic and resistance exercise (AE+RE), and the contralateral limb to resistance exercise (RE) only." (Lundberg. 2013)

  Before, as well as 15 and 180min minutes after the subjects underwent this training sessen, biopsies were taken and the glycogen content, the mRNA levels of vascular endothelial growth factor (EGF), peroxisome proliferator–activated receptor--gamma-coactivator-1 (PPAR-gamma), muscle RING-finger protein-1, atrogin-1 and myostatin, as well as the phosphorylated proteins mammalian target of rapamycin (mTOR), p70S6 kinase, ribosomal protein S6 and eukaryotic elongation factor were  measured. To ensure that no dietary factors would interfere with the results meals had been fully standardized on the day of the testing:
  

  "A standardized meal (pasta, tomato sauce, and juice) consisting of 2.21 g CHO/kg body weight, 22 g protein/kg bw, and 0.04 g fat/kg bw was provided at 8:00 p.m. the night before the experimental day. Subjects also had a standardized breakfast (1.01 g CHO/kg bw, 0.31 g protein / kg bw, and 0.24 g fat / kg bw) 1 h before the aerobic exercise session and lunch (2.02 g CHO/kg bw, 0.62 g protein/kg bw, and 0.49 g fat /kg bw) consumed 3 h before RE. These meals consisted of commercial energy drinks (Ensure Plus; Abbott Laboratories BV, Zwolle, The Netherlands). Water was allowed ad libitum at any time during the intervention." (Lundberg. 2013)

  As nice as it is to see a tightly controlled study, investigating a relevant topic and with trained healthy participant like this, I am really not a fan of these 'compare the left to the right leg' studies. And still, the fact that I am happy about any study into the whereabouts of different training modalities is neverthelsess not the only reason I am not going to beat a dead horse here.

  

  Figure 2: Unilateral peak concentric (CON) and eccentric (ECC) power (W) in knee extension and leg press during the experimental bout; data expressed relative to group baseline (Lundberg. 2013)

  The other and probably more relevant reason is that the data you see in figure 2 as surprising at it may seem  -- I mean who would have thought that the resistance training (RT) only leg would see a greater decline in force production during the experimental bout compared to baseline -- does not look like it had been skewed into this surprising direction by carry-over effect from one leg to the other or systemic factors such as central nervous system fatigue or the depletion of liver glycogen levels.
  
  In particular, we don't see anything of the expected drop in resistance training performance in the AE + RE leg due to the previous cardio workout. Even if it was only small, maybe statistically non-significant, common wisdom would dictate that it should be present! What we are seeing instead, however is a beneficial instead of a detrimental pre-conditioned effect in the 'cardio leg', of which you can hardly argue that it speaks in favor of the hypothesis that doing cardio must necessarily hamper your gains, if you allow enough time and food in between the morning and the evening workouts.
  
  It certainly looks as if the myth of the strength busting effects of any aerobic activity was about to fall and the corresponding protein expressions, the scientists measured before, 15min and 180min after the trial onyl support this notion.
  
  The image that emerges, when you take a closer look at the data in figure 3 is actually quite clear. At "pre" already, i.e. immediately before the resistance training part begins, the 'cardio leg' has and edge over the previously rested leg it won't lose in the course of subsequent hours. After all, despite the fact that at T = 180min some of the values have returned to baseline and/or the levels in the resistance training only leg have caught up, there is never a significant advantage of the resistance training only, over the aerobic + resistance training leg in the whole 3h period (respectively at the three intervals at which the biopsies were conducted).

  

  Figure 3: Selected markers of mitochondrial biogenesis and protein synthesis before during and 15, respectively 180min after the resistance training bout in the AE + RE and the RE only leg (a.u.; data adapted from Lundberg. 2013)

  Personally, I would still not consider these observations conclusive evidence of the superiority of aerobic + strength training in terms of its potential as a muscle builder (that it is a mitochondrial builder stands out of question). What is however undebatable (at least in this particular case), is that doing aerobics earlier in the day and lifting weight later in the day will not have a negative impact on either the performance or the measured markers of the exercise induced growth stimulus the resistance training session will have. It is rather, as the scientists point out that ...
  

  "[...] concurrent exercise elicited greater mTOR and p70S6K phosphorylation compared with RE. Although these differences were modest, if anything, they indicate that translational capacity was reinforced rather than compromisedby the AE + RE intervention. In parallel, myostatin was suppressed for longer time in AE + RE, with no obvious sign of exacerbated protein degradation. Thus, in contrast to the posted hypothesis, it seems that concurrent AE + RE may enhance skeletal muscle anabolic environment." (my emphasis in Lundberg. 2013)

  I guess, there is actually little to add to that, despite the important warning that you must keep an eye on your overall training volume, in case you want to follow this approach. In the end this means that you are switching to a two-times-a-day regimen, which can take its toll not just on the ability of your muscles to adapt and recover, but more importantly on the ability of your central nervous system to cope with this additional stressor. 
  

Can I do HIIT instead? For the first study, the answer probably is no. It makes no sense to use HIIT training as a regenerative means after a workout. For the second study I would guess the answer is yes. After all, the aerobic morning workout was pretty strenuous and glycogen depleting, so I don't see any reason why a brief HIIT training in the 10-20min range would not yield the same if not even better priming effects (cf. "The Anabolic Effects of HIIT" )

Bottom line: I would not say that any of these studies gives you, who are hopefully interested to build muscle and maintain optimal health a free ticket to do as much cardio, whenever you want. What this compilation does yet do, is debunk the myth that you have to become a sedentary slob and discard the cardiovascular and obvious fat loss benefits the implementation of moderate amounts of aerobic training into your regimen will yield just because aerobics will necessarily comprimise your gains, let alone burn away your muscles.

Timed appropriately and used in moderate, instead of excessive amounts, some 'cardio' could in fact offer an overlooked means to provide a greater growth stimulus and promote faster recovery - and that next to all the health- and conditioning related benefits, I guess even the hardcore-bros won't doubt.

References:

• Lundberg TR, Fernandez-Gonzalo R, Gustafsson T, Tesch PA. Aerobic exercise alters skeletal muscle molecular responses to resistance exercise. Med Sci Sports Exerc. 2013 Sep;44(9):1680-8.
• Tufano JJ, Brown LE, Coburn JW, Tsang KK, Cazas VL, Laporta JW. Effect of aerobic recovery intensity on delayed-onset muscle soreness and strength. J Strength Cond Res. 2013 Oct;26(10):2777-82.

Before, After or In-Between? Study Puts Another '?' Behind the Widely Accepted 'Cardio After Weights' Paradigm.

Image 1 (rippedfitness.com): As of late everyone picks on gals who believe they would get bulky, when they train with weights... I wonder, when people finally start picking on big, but chubby guys who still try to justify their laziness with the "conditioning work induces muscle loss" myth, when they are guzzling their sugary weight gainers.

I know that I am probably one of the few people with a bias towards lifting weight and high intensity interval training who does not discard the merits of steady state aerobics (LISS) as a third pillar of the exercise part of physical culture. In that I am however well aware that we all have only so much time to spare for exercise - although I believe each and everyone of us would be able to carve out another hour everyday, if we just streamlined our schedules and threw out some useless Internet surfing or TV watching, but this is another issue... it may thus be necessary or at least desirable for many of us, if we could combine strength and LISS sessions into a single session. Personally, I have been doing that for years and after some initial experimentation I have, for the most time, relied on the broscientific recommendation to do LISS after workouts (when I could not do it separately).

Cardio? Ok... but when? Before, after or in-between?

The recent publication of a study on the post-exercise response to concurrent endurance and resistance training published in the Journal of Sports Science and Medicine does yet make me question if there may not be better ways to combine weight lifting and light intensity steady state cardio training. To elicit whether you'd better walk on the treadmill at 60% of your HRmax before or after your weight lifting workout and whether there may not be an even better third protocol that would involve jumping back ond forth from the treadmill to the bench Andrea Di Blasio and her colleagues from the G. d’Annunzio University of Chieti-Pescara in Italy recruited 13 young previously untrained women (mean age 24.40y; BMI 21.28 kg/m²).

Figure 1: Outline of the 3 training protocols that were performed by all subjects (Di Blasio. 2013)

On three different occasions, each of the participants, who underwent an extensive initial fitness test and had been required to follow identical nutrition protocols before each of the three testing sessions, performed all three of the endurance / resistance training protocols, i.e.

• ERT - 30 min endurance training, first + 3x resistance training circuit*, 2nd
• RET - 3x resistance training circuit, first + 30min endurance training, 2nd
• AERT - [10min endurance training + 1x resistance training circuit] x3

note: the circuit training was performed in sissy mode, i.e. at 55% of the 1RM because "it allows working for 30-second consecutively" (Di Blasio. 2013)

...in random order. Resting energy expenditure, VO2, ventialtion, respiratory frequency, proportion of oxygen in the expired air were collected for 30 minutes via continuous indirect calorimetry (FitMate Pro, Cosmed, Roma, Italy) with the subjects in total rest and in a reclined position in a standardized and quiet room (please keep that in mind! We are NOT looking at intra-exercise energy expenditure, but what happens, when you head home or shower!) according to a standardized experimentally validated protocol (Compher. 2006).

Conventional wisdom fails, both alternatives useful - pick whatever suits your goals

The results, of this trial were - to say the least - more than surprising. Or ... well, honestly they were not. If you take a closer look at the plotted data in figure 2, you will realize that the RPE value, i.e. the rate of perceived exertion, Di Blasio et al. had elucidated visual analogue scale questionnaires, as well as the cardiovascular turned out to be the crucial parameters:

Figure 2: Resting energy expenditure (total and rel. to RPE, left) and changes in oxgyen consumption (VO2), ventilation and oxygen fraction in exhaled air relative to mean changes after ERT, RET and AERT training (based on Di Blasio. 2013)

Interestingly, the long-stading"resistance training first" principle (RET) turned out to be the least useful protocol current experimental setting (see implications, below). Rather, the study found

"[...] that AERT, compared with the other protocols, induced a higher metabolic rate by in- creasing EE, VO2, Ve and RPE during recovery from training, and independently of their pre-test values." (Di Blasio. 2013)

This is an interesting result, because it suggests that the hitherto certainly unappreciated alternation of strength and LISS training within one exercise session appears to elicit those post-exercise increases in EE, VO2 and ventilation, that are necessary to support the re-synthesis of adenosine triphosphate (ATP) / creatine phosphate (PCr), to replenish glycogen and oxygen stores, to propel lactate removal and circulation (Børsheim. 2003).

It stands do reason that all these processes are energy intensive. To (1) quantify all of them in kcal (I wonder how long you could survive if you ate kcal instead of foods and how your mitochondria would function if they burned kcal instead of nutrients) and (2) subsume them under the misleading term  "excess post-exercise oxygen consumption" (EPOC) and judge the "optimal" training regimen by its effect on EPOC is yet short-sighted, not just because "EPOC comprises only 6-15% of the net total oxygen cost of the exercise" (LaForgia. 2006), but also because this practice implies that the total or relative (as fat) amount of energy you expend in the immediate vicinity of  a workout was the main determinant of its effects on your metabolic health and physique.

F*** EPOC, the fat burning zone and the calories in vs. calories out hypothesis!

Figure 3: Figure 3: Changes of key enzymes envolved in the phosphorylation of key enzymes in the protein synthetic cascade in response to endurance (E) and combined endurance and resistance (E+R) training (calculated based on Sahlin. 2011; originally posted in "Resistance After Endurance Training Increases Mitochondrial Biogenesis & Protein Synthesis and Ramps Up Fat Metabolism").

That the results of the study at hand do yet still speak in favor of the mixed-mode AERT protocol - at least as long as your main intention is to perform a relatively light full-body conditioning workout at least 3x times a week - is thus not that it yielded the highest post-exercise energy expenditure, but that it did that at the (relatively) lowest rate of perceived exertion (see figure 2, left) and provided the greatest VO2 stimulus to initiate those beneficial metabolic adaptation which won't just reduce the huffing and puffing on subsequent training sessions, but will also help you build a bigger metabolic engine, that's going to keep you lean and help you shed more fat in the future. Apropos "metabolic engine", those of you who have been around for more than a couple of weeks, should actually remember my a post from November 15, 2011, in which I already discussed that adding strength to endurance training can turn even a 60-min cycling workout into a tree-trunk leg builder (see figure 3).

In conjunction with the study at hand, which is the first I know of that compared "cardio first", "cardio second" and "cardio in-between", directly, the results of the 2011 Sahlin study, which employed a true hypertrophy specific pyramid-style leg training after 60min of cycling (without a "hypertrophy first" control, though) do suggest that it may be about time to re-evaluate the bro-scientific standard protocol of "strength, first", "cardio, second" without the long overcome mantra of "you got to work out in the fat burning zone" in the back of your head.

Interestingly, enough, Yardley et al. have only recently reported that "doing cardio first" can make type I diabetics go hypo (Yardley. 2013). Though this may sound scary at first, it would suggest that, in healthy people, the expression of the energy sensor AMPK, as well as the the mitochondria building, fat browning protein PGC-alpha (cf. "If a High Fat Diet was a Pill, the Lay Press Would Celebrate it as Exercise in a Pill!") is probably higher and all the beneficial downstream effects on metabolic health and body composition more pronounced (as always you can of course also argue otherwise - if you want to get hightened leptin levels down, you'd better do it the exact other way around; cf. "Greater Reduction in Leptin With Cardio After Weights").

Suggestion for combining strength and cardio training in one session for,...

• strength - 15 min LISS before*
• hypertrophy - max. 25 min LISS before*
• fat loss (classic) - max. 40min LISS before
• fat loss (alternative) - 10min HIIT + 5min LISS + body part 1, 10min HIIT + 5min LISS + body part 2

* if you feel like it add a 10min HIIT session to the end

You may certainly argue that you would gain more strength without doing any cardio... still, the average O-lifting heavy weight look is probably not what many of you are training for, right? And when you think about it from a physiological perspective it would only appear logical that you better do your cardio first, lift second and add a ~5min cool-down to leave the gym before your protein synthesis peaks / begins to decline, than experience just that during a 45min LISS session after your workouts.

In this respect, even the "equipment hopping" of the AERT sessions, may have it's merit for advanced trainees. While it may certainly not be optimal to "bulk", switching back and forth from cardio to strength training could be a viable alternative for people whose main goal is to maintain the muscle mass while improving their conditioning - particularly when it is combined with short HIIT sessions 5-10min, followed by a short cool-down done twice before say chest and arms (e.g. HIIT > Chest > HIIT > Arms).

References:

• Børsheim E, Bahr R. Effect of exercise intensity, duration and mode on post-exercise oxygen consumption. Sports Med. 2003;33(14):1037-60.
• Compher C, Frankenfield D, Keim N, Roth-Yousey L; Evidence Analysis Working Group. Best practice methods to apply to measurement of resting metabolic rate in adults: a systematic review. J Am Diet Assoc. 2006 Jun;106(6):881-903.
• Di Blasio A, Gemello E, Di Iorio A, Di Giacinto G, Celso T, Di Renzo D, Sablone A., Ripari P. Order effects of concurrent endurance and resistance training on post-exercise response of non-trained women. Journal of Sports Science and Medicine. 2013 Aug; 11:393-39.
• LaForgia J, Withers RT, Gore CJ. Effects of exercise intensity and duration on the excess post-exercise oxygen consumption. J Sports Sci. 2006 Dec;24(12):1247-64. 

Some HIIT For Life & Less LISS For More! How to Burn 27,300 Kcal Extra W/out Losing a Single Extra Pound of Fat!

Image 1: Yep, you are right, the SuppVersity is the place to be to make sure you don't embarrass yourself during one of those potentially fatefully flirticious one-on-ones in the gym - Remember: Strong and Smart is the Newest Sexy ;-)

In view of the fact that you all seem to be enjoy the high intensity interval news aka "On Short Notice" items at the SuppVersity, I decided to do another double-feature today, somewhat similar to the "Weight Loss Threesome" three weeks ago. This time however not on sleep, TV and supplements, but on cardiovascular exercise for fat loss. For that purpose I have lined up a unique study about the longterm (!) beneficial effects of HIIT workouts on body composition, cardiometabolic risk factors, and conditioning of abdominally obese subjects (Gremeaux . 2013) and a study the results of which foster the surprising insight that 50% less can be 80% more when it comes to light intensity steady state (LISS) training for fat loss (Rosenkilde. 2013). So, let's get "without further delay" right to this sexually conservative, but contentwise highly experimentally one-on-one ;-)

Biggest Winners Combine Lifestyle Change With Optimized HIIT Workouts

In what the authors claim (and my personal readings in this area confirm) was the first study to analyze "the effects of a combined lifestyle intervention and optimized HIIT [regimen] on body composition, cardiometabolic risk, and exercise capacity in subjects with abdominal obesity", Vincent Gremeaux from the Cardiovascular Prevention and Rehabilitation Centre (EiPIC) at the Montreal Heart Institute found that their 9-months program which comprised of five individualized nutritional counseling by a trained dietician and 54-min (total) of supervised optimized high-intensity interval exercise and resistance training 2-3x times a week (+optional 2x continuous moderate-intensity sessions per week, such as walking and/or cycling) had profound effects on body composition, cardiometabolic risk, and exercise tolerance in the 62 of the 69 obese subjects (44 men, 22 women; BMI 35.8 +/- 5; age 53.3 +/- 9.7) from the babyboomer generation (Gremeaux. 2013).

Figure 1: Dietary and workout regimen, graphical overview (based on information from Gremeaux. 2013)

As my graphical summary in figure 1 goes to show, the workouts were a breeze compared to last week's Iranian HIIT Solution. And in view of the "guideline compliant" macronutrient composition it is actually quite astonishing, how pronounced the average and individual results of the subjects eventually were.
If anything than the loss of lean mass (figure 2, left) would be a thing to be slightly concerned about. On the other hand, this leaves much room for improvements, which would be easily achieved by

• really working out with weights you can only lift for 8-10 times and performing 3 circuits of free weight exercises with a focus on compound movements (if this is physically possible),
• using "all-out" sprints preferably also on the treadmill instead of the cycle ergometer for the HIIT workouts (as long as your conditioning allows for that)
• eating more protein and cutting back on carbs so that the total energy intake would keep about the same if you ate 1.5g protein/kg body weight per day and 20g+ of quality protein with every meal 

As long as you are still overweight that should suffice to get leaner, when you are already lean, though, you won't be able to make progress without a minor degree of temporary (2-6 weeks) caloric restriction in the ~20% range.

Tipp: Don't count calories, just eat some rice less, just one instead of two bananas, etc.; try to get used to the notion of eating food, not calories!

You see, the general rules apply to everyone, their practical realization, i.e. the number of workouts, the intensity and the duration will however be different and has, when all is said and done, to obey to one simple rule: You cannot expect your body to change, if the circumstances don't require change! This evolutionary-esque principle applies to anyone from the morbidly obese baby boomer to the ripped physique athlete in the prime of his twenties - regardless of who are and who you want to be, the only way to get there is to challenge yourself appropriately!

[for implications see end of today's post]

Burning 300kcal/day W/ LISS Produces Greater Fat Loss Than Burning 600kcal/day!

Image 2: If this looks like you on one of your twice daily 2h cardio workouts in the "fat burning zone", this must be your first time, here at the SuppVersity. If not, you already know that 5min here at the SuppVersity everyday will do more for your physique and overall health than with all the "cardio" you can possibly pack into your already overcrowded schedule!

Especially if you are a total beginner or someone who is already strength training intensely almost daily, you can run the risk of outtraining your regenerative capacities by adding in more than one longer HIIT workout. Moreover, my personal experience tells me that "mixing things up" and doing some "regular" light intensity steady state cardio, especially rowing or outdoor activities can really give you an unexpected edge, in terms of fat loss without really taxing your system. Interestingly enough, the results of a soon-to-be-published study be Mads Rosenkilde and his colleagues from the Department of Biomedical Sciences and Department of Human Nutrition at the University of Copenhagen in Denmark do actually support my experience, as the 64 moderately overweight (BMI: 25-30 kg/m², fat percentage ≥25%), sedentary yet healthy men without a past history of useless dieting (and over-exercising) who participated in the 13 week trial (compare that to the above 9-months trial!) lost an astonishing amount of 4kg of pure body fat with nothing else than "classic" steady state cardio (Rosenkilde. 2013)!

"Energy in - energy out = fat loss" - fail!

Over the course of 13 weeks, the participants took part in three supervised exercise sessions per week, which had to be performed at an average heart rate of >70% of their predetermined maximal heart rate. On the other four days they were free to engage in whatever physical activity they wanted, but had to wear a heart rate monitor that would allow them to decide, when they had fulfilled their daily 300kcal/day (MEDIUM) or 600kcal/day (HIGH) exercise dept. The log-files of the heart rate monitors were deliberately analyzed by the scientists every on a weekly basis, missed sessions had to be made good for and repeated non-compliance was penalized with immediate exclusion from the trial. Effectively, the guys in the HIGH dose arm of the study simply exercised longer at the same ~66-67% of their VO2_Max on the mean 6.2 "workout days" both groups had in common.

Contrary to what the scientists, who totally relied on their (stupid) calories in vs. calories out calculations, had expected these longer workouts and the associated increase in exercise induced energy expenditure did not result in either greater weight or fat loss in the highly compliant participants of the HIGH dose exercise group (compliance: 96% vs. 99% in the HIGH and MODERATE arms, respectively; statistically this difference was not significant).

Figure 3: Changes in body weight and fat mass (left) and "real" (=calculated based on weight loss) energy deficit the subjects accumulated over the 13-week study period (data based on Rosenkilde. 2013)

If you take a closer look at the data in figure 3 you will even realize that the 30 subjects who had initially been randomized to the MODERATE dose arm of the study and should thus expended ~27,300kcal less than their peers in the HIGH dose arm when the final measurements were taken, had lost slightly more total and fat weight than their harder training counterparts.

"Hey! Where are the weights, dude?"

Yet despite the fact that Rosenkilde et al. triumphantly report that the "energy balance was 83% more negative than expected in MOD, while it was 20% less negative than expected in HIGH" a closer look at the data in figure 3 will also reveal that the ratio of total to fat mass loss, i.e.

• 1.1 g of fat per 1g of total mass in the MODERATE dose group
• 1.4 g of fat per 1g of total mass in the HIGH dose group

does still speak in favor of doing a little bit more, than what is necessary to lose weight (I almost forgot: During the study period, the energy intakes did not differ between the groups and there were no significant differences between the subjects on low carb and the subjects on high carb diets wrt to the study outcome). This is all the more true, because the +1kg increase in lean mass (compared to a third sedentary control group this was even statistically significant) in the HIGH dose group went hand in hand with a significant increase in resting energy expenditure (+205kcal/day in HIGH vs. +192kcal in MODERATE).

However, I guess I don't really need to tell you the reason why I highly recommend that you still stick to short(er) and/or less frequent LISS (=light intensity steady state) workouts, do I? Yeah, right! Used more as a regenerative means, to play basketball or soccer with friends to take the dog for a walk or jog with your beautiful significant other through the park short(er) LISS workouts constitute an excellent counterpart to your obligatory weight lifting sessions and won't force you into the dreaded vicious circle of over-training (and under-eating), due to which the fat loss of so many trainees stalls, when the first couple of pounds have literally fallen off their hips.

Implications: Collectively these two studies would support the notion that all physical activity has its merit. They also emphasize the under-appreciated simple truth that both, the combination of a high intensity strength and moderate intensity LISS regimen (+ the occasional short HIIT workout) and a moderate intensity strength and high intensity interval training program (+optional moderate intensity LISS training) constitute effective ways to reduce your body fat percentage! With the former being more geared to the advanced trainee who is also looking to build some quality muscle mass and the latter being the workout of choice for the beginner who "just wants to look good naked", there are more than a billion permutations you will have to experiment with in order to identify not the best routine, but your best routine at a given timepoint in your career as a beginning, advanced, or elite physical culturist(highly suggested read: The "Step By Step Guide to Your Own Workout Routine").

References:

• Gremeaux V, Drigny J, Nigam A, Juneau M, Guilbeault V, Latour E, Gayda M. Long-term Lifestyle Intervention with Optimized High-Intensity Interval Training  Improves Body Composition, Cardiometabolic Risk, and Exercise Parameters in Patients with Abdominal Obesity. Am J Phys Med Rehabil. 2013 Jul 30.
• Rosenkilde M, Auerbach PL, Reichkendler MH, Ploug T, Stallknecht BM, Sjödin A. Body fat loss and compensatory mechanisms in response to different doses of aerobic exercise - a randomized controlled trial in overweight sedentary males. Am J Physiol Regul Integr Comp Physiol. 2013 Aug 1.

Are You Still Burning Calories or Already Losing Fat? Study Shows: 5x15 Min HIIT Reduce Body Fat & Improve Fitness Twice as Effectively as 5x40min of Classic Cardio

Image 1: The number of women striving to be strong & sexy is still too skinny.

Despite the fact that the slogan "strong is the new sexy" has become increasingly popular, as of late, my personal experience tells me that women are particular resistant to suggestions, let alone well-meant advice to drop "classic cardio" training all-together. Against that background the data from a study that has been published in the latest issue of the Journal of Sports Medicine and Physical Fitness, as convincing as it may be, is probably no more than another drop in the bucket, but hey... if there is only one women who's mental bucket is already chock-full it may be the one drop that will eventually make it spill over ;-)

"But didn't they lose more weight with classic cardio!"

What happens if you take 60 female overweight (BMI>25kg/m² and body fat >30%) university students and tell them they got to lose weight? Well, I guess, 45 will run to the next best newsdealer get their Shape, let alone Cosmopolitan and start starving themselves according to the latest diet fat from Hollywood, while the remainder will do just the same, except that they combine the starving with some "healthy" cardiovascular exercise in the mythical "fat burning zone". Now the former, i.e. the starvation diet, was not an option for any of the 60 Chinese women, as the design of the 12-week trial required them to maintain their regular diets, the latter, and even the walking or running in the "fat burning zone" was not really part of the experimental conditions the women were randomly assigned to:

• moderate intensity continuous training (MICT): 40min of jogging or walking at 50% of the individual VO2max 
• high intensity interval training (HIIT): 5x3min of running at 85%VO2max with 3min of active rest between the high intensity bouts
• sedentary control: no exercise at all

The exercise was performed on an outdoor track five times a week for a total of 12 weeks an elicited (remember: in the absence of any dietary interventions or restrictions!) pretty astonishing results in - and this must be said for the sake of fairness - both groups.

Figure 1: Changes in body composition and fitness parameters compared to baseline (Sijie. 2013)

If you take a closer look at the data in figure 1 it is yet evident that the 15min of HIIT exercise were not only less time-consuming, they also produced more pronounced and, what's even more important, more favorable changes in body composition, i.e. a greater reduction body fat percentage and waist-to-hip ratio, greater retention in lean mass (as evident from more pronounced fat loss in the presence of slightly lower reductions in BMI) and statistically significantly more pronounced improvements in cardiovascular fitness (VO2Max and ventilatory threshold) - exactly those domains, which should (but have never been) the domain of "cardiovascular" exercise ;-)

Not just for Chinese overweight women: Another recently published study by Astorino et al. confirms that the HIIT induced beneficial effects on VO2max are not restricted to otherwise sedentary, obese subjects, but will also occur in active, young men and women (age and body fat = 25.3 ± 4.5 years and 14.3 ± 6.4%). And that despite the fact that the subjects in the Astorino study performed only two sessions per week (4-6x 30s wingate tests = all out cycling followed by 5min active recovery) and the total duration of the study was no longer than three weeks (Astorino. 2013). In this context it is also worth mentioning that Ciolac et al. were able to show that young women with high familial risk for hypertension also derive greater benefits in terms of cardiovascular health improvements from aerobic interval vs. classic aerobic training (Ciolac. 2011).

Lose weight or lose fat? Look sick or look good? Burn calories or burn body fat? LISS or HIIT?

Despite all obvious limitations of this study it should thus be obvious that "cardio", regardless of whether you do it to improve your physique or overall fitness, must neither be time consuming nor should it be conducted in the "fat burning zone". Those of you who have been following the Step By Step Guide to Your Own Workout (specifically the Fat Loss Example Routine), will yet be aware that this does not imply that you must never perform "classic" low intensity steady state cardio. As a means of recreational activity on your off days, 20-30 minutes on a treadmill may actually help you recover from the "real" training sessions which will bring about those adaptation (fat loss and muscle gain) even women should be striving for if their focus is to improve the way they look and feel about their bodies.

A note on the right type of HIIT for you: If you compare the HIIT protocol in the Astorino to the HIIT protocol in the Sije study, it is pretty obvious that we are dealing with an all-out short burst approach (Astorino) vs. an high intensity longer burst approach (Sijie). In order to find the right HIIT protocol for you, you will have to reconsider your current training status and goals - with the general rule being: The fitter you are the more you should tend towards the shorter all-out bursts, because here, outside your comfort zone, is where the magic of adaptation happens. The more body fat you are still carrying, the more you should tend to longer high intensity bouts.

References:

1. Astorino TA, Allen RP, Roberson DW, Jurancich M. Effect of high-intensity interval training on cardiovascular function, VO2max, and muscular force. J Strength Cond Res. 2013 Jan;26(1):138-45
2. Ciolac EG, Bocchi EA, Greve JM, Guimarães GV. Heart rate response to exercise  and cardiorespiratory fitness of young women at high familial risk for hypertension: effects of interval vs continuous training. Eur J Cardiovasc Prev Rehabil. 2011 Dec;18(6):824-30. Epub 2011 Feb 28.
3. Sijie T, Hainai Y, Fengying Y, Jianxiong W. High intensity interval exercise training in overweight young women. J Sports Med Phys Fitness. 2013 Jun;52(3):255-62.