Eight HIIT Sessions on the Rowing Ergometer Cut Body Fat, Increase Adiponectin, VO2Max & Performance in National Level Rowers - Workmatched Classic "Cardio" Does Nothing

If you have hitherto ignored my previous advice (e.g. "Choosing Your Workout Style") to give the rowing machines a try, maybe the study at hand will rise your interest. Give it a try. It's an awesome whole body workout and highly effective, even if you just do 20min of steady state after lifting weights.

Yesterday you've learned that even the most idio... ah, I mean unconventional - not to say "experimental" in the literal sense - one-legged leg training routine is more likely to get you those six-pack abs, of which everyone appears to believe that it was a natural sign of outstanding health and a thing everybody must have (just like the new iPhone, you know ;-), than a bazillion of sit-ups. Today, you will see that a somewhat less "experimental" training regimen will not have you reach your goal faster and more efficiently, it will also have the welcome "side effect" of making you healthier and improving your conditioning. And you know what's the best about all that? It does not only work for sedentary baby-boomer, but also for highly trained athletes. 5 male and 2 female19(± 1.2)-year-old junior state and national level rowers from the Tasmanian Rowing Team (height: 1.77 ± 0.10 m, body mass: 74.0 ± 10.7 kg, body fat: 17.1%, VO2max 62.1 ± 7.0 mL·kg/min), to be precise (Shing. 2012).

Healthier, leaner, fitter - that's a HITTer ;-)

To evaluate the influence of two different training regimen, namely the traditional steady training (SST/LISS) on a rowing ergometer (a piece of equipment of which the regulars among you already know that I highly suggest you incorporate it into whatever cardio routine you may be doing), or a high intensity interval training (HIIT) variety of the latter the researchers from the School of Human Life Sciences at the University of Tasmania in Launceston, Australia put their participants, the aforementioned young national rowers, on two different workout protocols with matched cumulative energy expenditures (my emphases in Shing. 2012):

• SST: "The traditional training program involved rowers completing two ergometer sessions per week; one with a duration of 35 minutes and the other 40 minutes. [...] The intensity of each session
  was relatively low and more aerobic in nature when compared to the interval training protocol. The intensity of the traditional ergometer sessions was set to power outputs that corresponded to blood lactate concentrations of 2 and 3 mmol/l determined from the incremental exercise test."
• HIIT: "The interval training sessions consisted of eight 2.5 minute intervals at 90% of mean four-minute maximal power achieved during the incremental exercise test. Recovery between each interval was at an intensity of 40% of mean four-minute maximal power and the recovery duration was until heart rate returned to 70% of maximum heart rate, up to a maximum of five minutes."

The 2x four week experimental period (remember: we are dealing with a cross-over design, where all subjects participate in both protocols in random order) involved the incorporation of two ergometer sessions per week. Since all participants were part of the same squad the rest of their training regimen was identical, so that confounding factors - at least as far as the training is concerned - can be ruled out.

Body composition and adiponectin took a HIIT - a highly beneficial one that is ;-)

Performance tests were done and body fat mass (DXA), as well as a general blood profile and adiponectin values were taken at baseline and the end of both 4-week periods. Moreover, all participants had to keep a detailed training and diet log, so that the scientists could make absolutely sure that non of the effects they observed were due to unexpected changes in either activity levels or dietary habits.

Any potential influence of the randomized order, i.e. whether the rowers performed the classic training first and the HIIT sessions 2nd or vice versa was ruled out by statistical means before the scientists eventually analyzed their data sets and got the following results:

Figure 1: adiponectin levels before (pre) and after the respective workout at the beginning and end of the respective 4-week training period and body fat levels before and after 4 weeks of steady state (SST) or high intensity interval training (HIIT) in national level rowers (Shing. 2012)

I must admit, the changes are not earth-shattering, but there are changes - beneficial ones that is  - and they are statistically significant despite the small number of participants, and the fact that the subjects were already highly trained individuals and - I figure this may be the most convincing argument not to discard this effects - participated in no more than a total of only 8 HIIT sessions.

Bottom line: I guess, you could certainly argue that the novelty of the training stimulus was part of the reason, the HIIT regimen had so beneficial effects on the fitness, body composition and even the adiponectin levels of these already highly trained rowers (Adiponectin? That's the "new leptin", which promotes insulin sensitivity and exerts profound anti-inflammatory effects); but does this take away from the efficacy of this 4x2.5 min @90% max. + 5min active rest high intensity interval training regimen? I don't think so.

Click here to learn more about the "Iranian HIIT Solution" a minimalist program with maximal results

There is nonetheless one thing I want to add before I close the SuppVersity doors for today. The 4x2.5 minute protocol is certainly appropriate for trained athletes; in fact, previous studies even suggest that it requires those long(er) intervals in order to elicit gains in VO2max in highly trained (endurance) athletes (e.g. Franch. 1998; Laursen. 2002). The initially mentioned sedentary baby-boomer - obese or not - may however be better off, if they follows a different regimen, such as the one I outlined in the "Iranian HIIT Solution" (see image on the right) and incorporate that in a three-day split (e.g. A, B, hypertrophy, C strength) or a two-day full body circuit training.

The main message here is that starting out "low" (in terms of both volume and intensity) is not just possible, it's even advisable, so that there is still enough room to do more, and/or preferably up the intensity. I know I have been telling you that before, but I feel it's worth stating again: Real cardio training, i.e. the type of training that strengthens the cardiovascular system is progressive. If you do the same thing day in and day out the best you can hope for is to keep the status quo. Remember that before you start out way too high (esp. on the volume side of things) and either bunk directly, or end up without any room to make progress.

References:

• Franch J, Madsen K, Djurhuus MS, et al. Improved running economy following intensified training correlates with re-duced ventilatory demands. Med Sci Sports Exerc 1998; 30: 1250-6.
• Laursen PB, Jenkins DG. The scientific basis for high-intensity interval training: optimising training programmes and maximising performance in highly trained endurance athletes. Sports Med. 2002;32(1):53-73.
• Shing CM, Webb JJ, Driller MW, Williams AD, Fell JW. Circulating Adiponectin Concentration AND BODY composition ARE Altered in Response to High-Intensity Interval Training. J Strength Cond Res. 2012 Dec 4.

Reduced Exertion High Intensity Training - A Minimalist 2x20s HIIT Protocol For The Male Convenience Generation.

Image 1: Looks like humans are not the only lazy creatures, in these days of unhealthy convenience.

Laziness, it seems, is utterly human. If you look around, these days, it appears as if we were genetically programmed to be bone idle. And, from an evolutionary perspective, we may actually be. After all, moving around, hunting and gathering was an obligatory part of our lives in 99% of the human history. It was thus only consistent that our genes would tell us to sit down at the fireplace and relax, once we had found enough to eat on a given day... (un-)fortunately things have changed since those early days. Not only have we moved out of our caves, we have also found ways to radically reverse the ratio of activity to inactivity in our lives.

"Convenience" is the buzzword of the modern western civilization and the obesity epidemic is its unwanted consequence.

A consequence, which is yet by no means inevitable. After all, we all know that getting our behinds off our couches and into the gym, and setting the dietary recommendations of the (fast-)food industry, ahh... pardon, the government at naught would solve the problem, if ... yeah, if there was not this aforementioned genetically programmed laziness that makes the couch so much more appealing to us than the hard benches in the gym...

Sacrifice 30min per week of your TV-time and live to see your grandchildren graduate

A recent study from scientists from the United Kingdom does yet show that you could still spend more than enough time in front of your beloved television set, if you just performed what what Richard S. Metcalfe and his colleagues from the United Kingdom call the "minimal amount of exercise for improving metabolic health" (Metcalfe. 2011) - a 3x per week 10min exercise regimen with no more than two (yes, only 2x!) all-out sprints.

Figure 1: Outline of the training protocol, the black bars indicate all-out sprints at a breaking force equivalent to 7.5% of the individuals body weight (directly adapted from Metcalfe. 2011. Fig. 1)

As you can see in the outline of the experimental protocol, the 29 healthy and normal-weight, but sedentary young (~23y) men (n=13) and women (n=16) did not even have to start with 2x20s sprints. They rather built up to it, by starting out with a single 10s all-out cycle-ergometer sprint at a braking force equivalent to 7.5% of their body weight in the first week of the 6-week study period and built their exercise capacity from there.

Image 2: "Cardio" does not have to be steady state.

Note: If you have not read my previous blogposts on HIIT, you may have missed the information that interval training (not necessarily at the maximal intensity, though) is suitable for everyone - even heart disease patients (cf. Interval, not Steady State Aerobics is the Way to Go - Even for Patients with Myocardial Infarctions!). This has been confirmed only recently by Neil A. Smart et al. who found that "[i]ntermittent exercise may improve functional capacity [of congestive heart failure patients] to a greater extent than continuous exercise" (Smart. 2011) - and that despite the fact that both continuous (30min), as well as interval training (60min, 1 min cycling, 1 min rest) were performed at the same low intensity.

The rest of the 10-min exercise sessions, the subjects were pedaling along at 60W, which is about as much as it takes so that you do not fall off the bike, because of the lack of resistance that is required to stabilize yourself on the bike. The latter would have been tragic, at least if you are a man, because that would have counteracted the surprisingly (not for who has read about the magic of HIIT here at the SuppVersity before) profound effects this regimen, for which the scientists coined the name "reduced exertion high intensity training" (REHIT), had on the glucose homeostasis of the male subjects.

Figure 2: Changes in VO2Max, glucose and insulin area under the cure in response to oral glucose tolerance test in men and women after 6 week of "reduced exertion high intensity training" (data calculated based on Metcalfe. 2011)

As the data in figure 2 shows, the statistically more than significant decreases in the area under the glucose (-12%) and insulin (-39%) curve (AUC) measured during an oral glucose tolerance test was exclusive to the 13 male participants - and that despite the fact that both, male as well as female study participants exhibited similar improvements in their individual VO2Max (+15% in men; +12% in women).

(RE)HIIT only for men?

As far as the underlying reasons for these gender differences are concerned, the scientists are pretty much at a loss, stating that this could be due to "the low statistical power of our study, with only eight female subjects performing the REHIT", " differences in metabolic perturbations during the brief high-intensity cycle sprints",  and the 3-day delay after the last HIIT session before the glucose tolerance test was done (as a SuppVersity reader you will be familiar with the notion that the "anabolic barn door" is wide open for 24-48h), so that "insulin sensitivity was improved in female subjects at an earlier time-point". Now, I do not want to sound like a himbo, but I would say that another observation the scientists made, provides a much better explanation:

[...] we observed that some of the female volunteers struggled with the transition from 60 W to the all-out sprints, and were unable to substantially increase their pedal frequency, and thus their power output during the sprints. This may have increased the aerobic contribution to energy supply and reduced glycogen depletion.

In other words, what was supposed to be a sprint turned out to be a sluggish ordeal. The slightly, but statistically significantly higher rates of perceived exertion (+10%) in the female study participants corroborates the assumption that the women simply did not burn enough glycogen. If we do now also consider the results of a 2008 study by Hagobia et al. who report that

[...] in women, exercise altered energy-regulating hormones in a direction expected to stimulate energy intake, regardless of energy status. In men, the response to exercise was abolished when energy balance was maintained.

It appears obvious that an increase in pedaling frequency by adapting the resistance to the individual fitness levels and dietary controls may be necessary to render this minimalist "REHIT" protocol productive for the fairer sex.

Figure 2: Comparison of changes in VO2Max, glucose and insulin area under the cure in response to oral glucose tolerance test subsequent to 6 weeks of REHIT, or 10 months of "classic cardio" exercise, or dietary intervention (data calculated based on Metcalfe. 2011 and Dengel. 1996)

The comparison of this 6 week exercise program with the results of a 10 months intervention program in likewise healthy sedentary, but older men (45y) who exercised 3x a week for 40min (steady state) at 75-85% of their maximal heart rate, goes to show that it would well be worth making the REHIT protocol work for women, as well (Dengel. 1996). After all, the steady state endurance protocol in the Dengel study was not only four times more time-consuming (plus, the intervention period was 6.6x longer) than the modified HIIT protocol in the Metcalfe study, it also failed to improve the glucose response to the oral glucose tolerance test and produced less pronounced improvements in insulin sensitivity (cf. insulin AUC in figure 3). The mild caloric reduction (-300-500kcal/day) that was imposed on another group of the study participants, on the other hand, yielded similar reductions in glucose and insulin AUCs as the REHIT protocol in the Metcalfe study that was accompanied by a body weight reduction of ~10%, a reduction in body-fat of -5.8% and essentially no loss in fat free mass!

Note: Unfortunately, Metcalfe et al. did not measure the body composition of the study participants. In view of the results of the Whyte study (Whyte. 2010), I cited in the Intermittent Thoughts on Healthy Weight Loss, where the participants lost -2.4cm of their allegedly obese bellies within no more than 2 weeks of doing HIIT, as well as the well-established correlation between insulin resistance and the size of your beer-belly, it is very well possible that the male participants in the Metcalfe study will have lost some body fat doing no more than 8.67 minutes of all out cycling spread across 18 training sessions in 6 weeks... and if they didn't their diet probably was still too convenient ;-)

The (in-)convenient truth about your future

Taken together the results of these studies suggest that a) steady state aerobic exercise is pretty pointless, b) even a minimalist HIIT regimen goes a long way, as long as c) you really hit it hard and d) adhere to your regular (hopefully non-convenient) diet, or even better e) introduce a slight calorie deficit. In other words, without at least some "inconveniences" as far as nutrition and exercise are concerned, chances are that YOU will either remain or become one of the 34,004,946 obese human beings that are now populating a planet where the US alone spend 1,550,566$ per day on the detrimental health consequences of the"convenience" of its citizens (data from Obesity Statistics).

"Training in the Zone", Does it Work, After All? Middle-Aged Women Lose 8% Fat in 10 Weeks, Effortlessly. Plus: Weight Loss & Gain Patterns in African Americans

Training in the fat burning zone works. But the claim that it was the best way to lose weight is certainly subject specific.

Time for a brief overview of the latest research on obesity, it's health consequences and potential causes. I mean, you don't really believe that the result of a recent review in Nutrition Reviews is more than the sum of biased research that appears to hilariously suggest that "grain products are more protective than fruits and vegetables" (Fardet. 2014). We have heard that way too often and just like the claim that "dairy/milk products have a neutral effect on the risk of diet-related chronic diseases, while red/processed meats tend to increase the risk" (Fardet. 2014) we have not yet made any progress in out battle against obesity, type 2 diabetes, and various types of cardiovascular disease and cancer.

It does not always have to be HIIT, ladies and gentlemen, trainers & trainees

Never Train To Burn Calories!

Tabata = 14.2kcal /min ≠ Fat Loss

HIIT vs. LISS - Efficiency?

Making HIIT a Hit Part I/II

Making HIIT a Hit Part II/II

HIIT Ain't For Everyone

• Training in the (fat) burning zone: In a recent study scientists from the University of Southern Queensland were not able to demonstrate the superiority of training at an intensity that equaled their thirty 45-59 year old female subjects maximal fat oxidation intensity (Tan. 2014). But this was not due to the fact that this form of training is not effective, but rather a result of the five 1h sessions of steady state cardio in "the fat burning zone" was the only form of training tested.
  
  What the researchers did find, though, was that the exercise group obtained significant decreases in body mass, BMI, body fat % and abdominal fat mass, as well as the concentrations of triglycerides, serum leptin and blood glucose.
  

  

  Figure 1: The changes in body composition with 5x / week 1h of cardio in the zone in the absence of dieting were quite impressive in this 10-week study (Tan. 2014)

  The activity of lipoprotein lipase was increased in trained participants, there were no changes in these variables in the Control group.
  
  In addition, there was no significant change in daily energy intake for all participants before and after the experimental period. In this particular study, the often derided cardio training "in the zone" did thus work its often doubted magic and shed 8% of the subjects body fat without dieting.
• Patterns of weight change in African Americans: Even more so than the US citizens with Caucasian ancestors, the group of African Americans is threatened by ever-increasing obesity rates. By trying to identify broad categories of people with likely different program outcomes in a large weight loss intervention study, scientists from the Center for Clinical Epidemiology and Biostatistics at the University of Pennsylvania Perelman School of Medicine tried to identify treatment approaches that would better position program enrollees for success.
  
  

  

  Figure 2: Obesity is not an African American exclusive problem in the US, but the obesity rates - specifically for the women - are still higher in AA vs. CC citizens (Ogden. 2014).

  What the researchers found was that there are three general patterns that distinguish the "big losers" in their program into people with a...
  
  1. mean weight loss of approximately 2 kg (n = 5 519); 
  2. mean weight loss of approximately 3 kg at 1 year, followed by 4 kg regain (n 5 61); 
  3. mean weight loss of 20 kg at 1 year followed by 4 kg regain (n = 524).
  In a final multivariate analyses, were also able to show that a higher BMI predicted having pattern 2 (+10%) or 3 (+42%), and higher dietary fat scores were predictive of a lower odds of having patterns 2 (-63%) or 3 (-67%).
  
  While a weight regain of 4kg sounds huge - losing 20kg within one year and regaining only 4 means that you still lost 16kg, which is not bad and speaks in favor of the "the fatter you are, the easier you can lose tons of weight" truism. Moreover, the association with high dietary fat intakes underlines that the often cited benefits of eating more fat will occur only if the carbohydrate content of the diet is severely reduced. All in all, the study results are yet far too general to use them to deduce better weight loss prescriptions. 

Suggested read: More Than 3x Higher EPOC Induced Energy Expenditure With HIIT vs. LISS! But Does That Really Matter? Plus: Why Headlines Like This May Compromise Your Progress | read more.

Bottom line: It will certainly depend on the amount of exercise, the physical fitness and the degree of overweight, whether or not classic "fat burning" training works or not. The results of the study Tan et al. present in their latest paper, however, clearly indicate that trainers and trainees (esp. those who still have a relatively long way to go to get back to a normal body weight) should not underestimate the benefits of this derided type of exercise.

Speaking of "to underestimate", one should not underestimate the power of fast weight loss either. The African American participants who lost 20kg of body weight in the first year of the studies, Morales et al. reviewed did after all lose 14kg more weight than the "healthy losers" with their pathetic 2kg weight loss per year and no weight regain.

A result that should remind you of the recently published evidence that "slow and steady" has no significant advantage over rapid fat loss (Purcell. 2014; Yamada. 2014).

References:

• Fardet & Biorie. "Associations between food and beverage groups and major diet-related chronic diseases: an exhaustive review of pooled/ meta-analyses and systematic reviews." Nutrition Reviews (2014).
• Morales, Knashawn H., et al. "Patterns of weight change in black Americans: Pooled analysis from three behavioral weight loss trials." Obesity (2014). 
• Ogden, Cynthia L., et al. "Prevalence of childhood and adult obesity in the United States, 2011-2012." JAMA 311.8 (2014): 806-814. 
• Purcell, Katrina, et al. "The effect of rate of weight loss on long-term weight management: a randomised controlled trial." The Lancet Diabetes & Endocrinology (2014).
• Tan et al. "Positive effect of exercise training at maximal fat oxidation intensity on body composition and lipid metabolism in overweight middle-aged women." Clin Physiol Funct Imaging (2014).
• Yamada, Tomohide, Kazuo Hara, and Takashi Kadowaki. "Abstract P084: Influence Of Amount And Rapidity Of Weight Loss On The Risk Of Subsequently Regaining Weight And Drop-out From Treatment Among Patients With Severe Obesity Dieting In Hospital Without Bariatric Surgery." Circulation 129.Suppl 1 (2014): AP084-AP084.

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. 2012) -- 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. 2012). 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. 2012). 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. 2012) -- 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. 2012) -- 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 2012, 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. 2012)

  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 . 2012) -- 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 . 2012)

  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. 2012) -- 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. 2012).
  
  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. 2012) 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. 2012). 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. 2012)

  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. 2012;2012:465020. doi: 10.1155/2012/465020. Epub 2012 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/h2012-111. 
• 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. 2012 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. 2012 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. 2012;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/h2012-115
• Shetty RA, Forster MJ, Sumien N. Coenzyme Q(10) supplementation reverses age-related impairments in spatial learning and lowers protein oxidation. Age (Dordr). 2012 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. 2012 Nov 12.

New "Fasted Cardio"-Study Falsifies the Myth of Superior Long-Term (4 Week) Fat Loss on a Moderate Energy Deficit

If we go by the convincing results of the study at hand, the fasted cardio myth is obviously busted.

Sometimes the day you've been waiting for comes faster than you'd thought... no, I am not talking about a teen's eighteens birthday or Christmas (reminds me, I still have to buy a ton of presents), but rather of the recently hinted at "fasted cardio study" by Brad Jon Schoenfeld, Alan Albert Aragon, Colin D Wilborn, James W Krieger and Gul T Sonmez.

The study of which I wrote only 2 days ago in my article about the 50% increase in fatty acid oxidation in fasted vs. fed morning cardio (learn more). And it is in fact the study which may finally solve the "Is fasted cardio good for your weight loss?"-question.

In contrast to the previously discussed paper, Schoenfeld et al. who started with the common hypothesis that "performing aerobic exercise after an overnight fast accelerates the loss of body fat" (Schoenfeld. 2014), did not content themselves with measures of acute fatty acid oxidation. What they did was a study to investigate the actual changes in fat mass and fat-free mass following four weeks of volume-equated fasted versus fed aerobic exercise in young women adhering to a hypocaloric diet.

Want to get stronger, bigger, faster and leaner? Periodize appropriately!

30% More on the Big Three: Squat, DL, BP!

Block Periodization Done Right

Linear vs. Undulating Periodizationt

12% Body Fat in 12 Weeks W/ Periodizatoin

Detraining + Periodization - How to?

Tapering 101 - Learn How It's Done!

Needless to say that this study has the potentially to give us reliable insights with respect to the previously formulated question, because their subjects, twenty healthy young female volunteers were randomly assigned to 1 of 2 experimental groups,

• a fasted training (FASTED) group that performed exercise after an overnight fast (n =10) or
• a post-prandial training (FED) group that consumed a meal prior to exercise (n =10)

not for one or two testing days, but for 4 weeks! The training itself consisted of 1 hour of steady-state aerobic exercise on a regular treadmill (0% incline) and was performed for 3 days per week for the previously mentioned total study duration of 4 weeks.

"Subjects performed a warm-up for the first 5 minutes at an intensity equating to 50% of maximal heart rate (MHR), determined by the formula 220 - age, then increased intensity to 70% MHR for the next 50 minutes, and finished with a 5 minute cool down at 50% MHR. Heart rate monitors (model F7U, Polar Electro Inc, Lake Success, NY) were used to ensure that exercise remained at the appropriate intensity." (Schoenfeld. 2014)

To ensure that (a) the subjects actually trained and they would (b) only do the prescribed standardized volume of exercise, all training sessions were supervised by research assistants who were upper level undergraduate students in exercise science and the subjects were instructed to refrain from performing any additional structured exercise for the duration of the study.

One thing to consider: I would not fully discard fasted cardio, yet. Even if the resulrs of the study are convincing. It's one study that simulates a specific scenario. In a real world scenario you will often have people, who do shorter fasted cardio sessions, extend the fast and thus reduce their overall energy intake. This is similar to breakfast skipping, which works magic if you don't compensate for the lack of energy intake in the AM (learn more). In the study at hand this "side effect" of morning cardio didn't exist, because of the standardization of the dietary intakes of the female participants. This is perfectly correct from a science perspective, but may still be a reason the real world results you or your clients see may differ from the null-result in the study at hand.

Subjects were provided with customized dietary plans designed to induce a caloric deficit. In that, their total caloric intake was calculated on the basis of the Mifflin-St. Jeor Equation, which yields adequate, but obviously not 100% precise measurements of the resting metabolic rate (max. 10% off in non-obese adults according to Frankenfield. 2005). Since the same method was used for both groups, any possible inaccuracies, due to which the real caloric deficit among the women may not be identical to the calculated one, should carry no real weight, though. And we can simply assume that all women were in the same ~500kcal/day energy deficit the researchers thought to create.

Figure 1: Nutrient composition and total energy intake of the subjects in both groups (Schoenfeld. 2014)

In addition to their regular diet, the adherence to which was monitored on a regular basis, the subjects received a meal replacement shake either

• immediately prior to exercise for the FED group or
• immediately following exercise for the FASTED group,

with this nutritional provision carried out under the supervision of a research assistant. The "Pursuit Recovery" (Dymatize Nutrition, TX) shake you could also buy at your local GNC contains 250 calories, total, and 40 g carbohydrate (from maltodextrin and organic cane sugar), 20 g protein (from whey protein isolate + added leucine), and 0.5 g fat (residues).

Let's  take a look at the results now

As you can see in Figure 2, both groups showed a significant loss of weight (P =0.0005) and fat mass (P =0.02) from baseline, but no significant between-group differences were noted in any outcome measure (which means, that all the differences you see are "random").

Figure 2: Pre- vs. Post-study body composition measures (Schoenfeld. 2014)

As Schoenfeld et al. rightly point out, their findings clearly "indicate that body composition changes associated with aerobic exercise in conjunction with a hypocaloric diet are similar regardless whether or not an individual is fasted prior to training" (Schoenfeld. 2014) - in other words, in this pretty realistic scenario (I hope nobody starves himself after a 1h morning cardio session for another 4-8h) the myth that morning cardio on an empty stomach would accelerate fat loss is thus busted.

Bottom line: The assumption that the consumption of an insulinogenic pre-workout meal as it was used in the study at hand and a subsequent reduction of fatty acid oxidation during the workout would induce a shift from fat to carbohydrate oxidation (not measured in the study at hand, but previous studies show that this is the case) and have significant effects on an individual's long-term fat loss on an energy reduced diet is thus falsified.

The study at hand shows that the 50% increase in fatty acid oxidation w/ fasted cardio does not translate into increased fat loss | more

You could still argue that it may be beneficial if there is no energy deficit involved, for example by improving glucose levels as it was reported by Van Proeyen et al. (2013) in a study with a hyper-caloric energy intake (~bulk), but that's a whole different story.

Or you could argue that there is an albeit non-significant trend for an increased loss of fat mass in the FASTED group (inter-group difference = 33%, but the latter was (a) paid dearly for by an almost 2x higher increase in lean mass loss (inter-group difference = 60%) and stands (b) in contrast to the non-significant greater reduction in abdominal fat in the FED group as it is signified by changes in waist circumference.

For the time being, the long-standing "myth" that fasted cardio would lead to a significant acceleration has thus to be considered "questionable", if you put 100% faith the statistical accuracy of the study at hand (with only 10 participants in both groups, I am inclined not to do that) even "busted". For so long, at least, until another study, maybe one with more participants (which would allow to really figure out how "significant" the difference actually was), but a similar strict standardization, will show that it works. In that case, we would have to find out could have been that made the difference - could be the sex or training status of the subjects, the extend of the caloric deficit, the total protein intake (which was comparatively low), the type of the pre-workout meal or the form of cardio training that was used... Comment on Facebook!

References:

• Frankenfield, David, Lori Roth-Yousey, and Charlene Compher. "Comparison of predictive equations for resting metabolic rate in healthy nonobese and obese adults: a systematic review." Journal of the American Dietetic Association 105.5 (2005): 775-789.
• Van Proeyen, Karen, et al. "Training in the fasted state improves glucose tolerance during fat-rich diet." The Journal of physiology 588.21 (2010): 4289-4302. 
• Schoenfeld, Brad, et al. "Body composition changes associated with fasted versus non-fasted aerobic exercise." Journal of the International Society of Sports Nutrition 11.54 (2014)

Fasted Cardio Before Breakfast Increases 24h Fat Oxidation by Almost 50% over Doing AM+PM Workouts, But This Does Not Necessarily Mean That You Will Lose 50% More Fat

Can fasted cardio switch on your "fat burning mode. And, more importantly, will it help you lose body fat faster?

Before you get overtly excited about this being the study to finally solve the "fasted cardio" conundrum (i.e. answer the question "Will fasted cardio promote fat loss?"), I want to warn you. To answer this question, we will have to wait for Brad Schoenfeld's latest study on the chronic effects of fasted cardio to be released.

The study at hand, which was conducted by researchers from the Graduate School of Comprehensive Human Sciences at the University of Tsukuba can only inform us about the acute (24h) metabolic effects of cardio at different timepoints and with different amounts of food in the tummy (Iwayama. 2014).

High intensity interval training aka HIIT is more than just an alternative for steady state.

Never Train To Burn Calories!

Tabata = 14.2kcal /min ≠ Fat Loss

30s Intervals + 2:1 Work/Rec.

Making HIIT a Hit Part I/II

Making HIIT a Hit Part II/II

60s of HIIT per week suffice!

In the experiment the nine young male endurance athletes, whose mean age was 23.2 ± 2.7 years of age (height: 168.4 ± 5.7 cm | weight: 59.5 ± 1.2 kg | body fat: 11.6 ± 0.6 %) and who had a relatively high cardiovascular fitness (O2max was 71.7 ± 6.4 ml/kg/min), performed three different types of exercise at different times in the day during a 42h stay in a metabolic chamber. 

• 100 min exercise before breakfast (AM),
• 100 min exercise after lunch (PM) or
• two sessions of 50 min exercise before breakfast and after lunch (AM/PM),

All the exercise sessions were performed at the same relatively low intensity of only 65% of the subjects' individual VO2max and repeated the day after under different caloric conditions. Thus, the actual experiment that was designed to investigate the effects of "cardio" on empty vs. full stomach, the effects of the duration and the time of the day, once in energy balance (2464 ± 75 kcal/day in day 1) and once in an energy deficit (3544 ± 127 kcal/day in day 2). The macronutrient composition (15 % protein, 25 % fat and 60 % carbohydrate) and timing of the meals was identical for all conditions. The contribution of the breakfast, lunch and supper to total 24-h energy intake were 32 %, 34 % and 34 %, respectively.

Figure 1: 24h fat and glucose oxidation during the two trials (fed condition) measured pretty reliably
in a metabolic chamber (Iwayama. 2014)

The scientists observed that the 24h energy expenditure was similar among the trials (that's why all three bars in Figure 1 have the same height). The 24h fat oxidation, on the other hand, was significantly higher in the 100 min trials and highest, when the 100 minutes of cardio were performed fasted in the AM (1142±97, 809±88 and 608±46 kcal/24-h in descending order of its magnitude for AM, AM/PM and PM, respectively).

Figure 2: Relations of 24-h fat oxidation to average (r = -0.52, P < 0.01) and nadir (r = -0.72, P < 0.01) of relative energy balance were plotted on panel (left) and (right), respectively (Iwayama. 2014).

If you take a look at Figure 2, you will also see that the increase in fatty acid oxidation correlated with the nadir of energy balance (Figure 2, right). In other words: The higher your cardio induced energy debt (as in doing cardio on empty), the greater the increase in 24h fatty acid oxidation.

Since the overall energy expenditure was identical in all trials, you should not be surprised that the increase in fatty acid oxidation in the AM group went hand in hand with a decrease in 24h glucose oxidation. A decrease of which the data in Figure 1 indicates that it largest in the AM (2062±96 kcal/24-h) trial, and hardly different for the PM (2374±114 kcal/24-h) compared to the AM/PM trial (2558±110 kcal/24-h), in which the fatty acid oxidation had been the lowest.

For people with type II diabetes interval training and thus burning more glucose than fat during the workout would be the preferred method. At high intensities you will burn a lot of fat after the workout, anyway (learn more). And even at low intensities, interval training is more effective than "steady state". Only recently, scientists from the University of Copenhagen have been able to show that at intensities that were as low as 40% VO2max during active rest and 70% VO2Max during the intervals, interval training is more beneficial than steady state cardio training with identical energetic costs (Karstoft. 2014).

Fat oxidation up, glucose oxidation down: At first sight, a 47% difference in fatty acid oxidation sounds like a huge advantage, but the fact that you oxidize fat, not carbohydrates does not necessarily mean that this fat (a) comes from your belly and other areas, where you may want to lose it, and (b) will not be restored after the workout.

In a caloric deficit, on the other hand, one could cautiously argue that burning more fat for fuel could lead to a slightly faster depletion of the adipose energy stores and thus slightly (not by 50%!) accelerate your weight loss. Plus: As long as you burn fat for fuel, your chances of running low on blood sugar and experiencing hunger pangs and cravings will be significantly reduced.

For the average physical culturist, there is yet another significant benefit: All the glucose / gylcogen you don't use during your cardio workouts will be available for your strength training sessions, where you will need them to lift heavy and thus promote lean mass retention  | What are your experiences with "fasted cardio"? Comment on Facebook!

References:

• Iwayama, K. "Transient energy deficit induced by exercise increases 24-h fat oxidation in young trained men." Journal of Applied Physiology Published (2014). Ahead of print.
• Karstoft, Kristian, et al. "Mechanisms behind the superior effects of interval vs continuous training on glycaemic control in individuals with type 2 diabetes: a randomised controlled trial." Diabetologia 57.10 (2014): 2081-2093.

HIIT or LISS - A Question of Efficacy? High Intensity Interval Training Kickstarts Fatty Acid Oxidation & Metabolism to Make Up for the Higher Energy Exp. During LISS in 24h

If you ever wondered why you're huffing and puffing for hours after your HIIT sessions, here is the answer!

Your oxygen consumption can be used as a measure of fatty acid oxidation and total energy demands. It is one of the frequently used output variables in training studies and it is often cited as one of the arguments of the friends of "classic" cardio training like jogging on a treadmill or cycling at a medium intensity. Why? Well, if you cycle for one hour you will obviously consume more oxygen (O2), than you'd do within 10 minutes of high intensity interval training, right?

In a recent study scientists from the Department of Kinesiology at the Ivor Wynne Centre of the McMaster University in Hamilton, Ontario (Canada), Lauren E. Skelly and colleagues tested whether this initial advantage, i.e. the increased VO2 consumption and thus energy expenditure in response to the exercise, would last 24h (Skelly. 2014).

You can learn more about HIIT at the SuppVersity

Never Train To Burn Calories!

Tabata = 14.2kcal /min ≠ Fat Loss

30s Intervals + 2:1 Work/Rec.

Making HIIT a Hit Part I/II

Making HIIT a Hit Part II/II

HIIT Ain't For Everyone

To this ends, the researchers recruited nine healthy young men (age = 21 ± 1 years, body mass = 91 ± 15 kg) and had them perform 3 trials in random order in a repeatedmeasures design.

• The HIIT treatment involved 10 × 60-s intervals at a workload that elicited 90% HRmax with 60 s of active recovery at 50 W. 
• The END protocol consisted of cycling at a workload that elicited 70% of HRmax for 50 min. 
• Control protocol: No exercise was performed in the control trial (CON). 

The HIIT and END protocols were selected, because previous research has reported similar changes in body composition between HIIT and longer (40–60 min) bouts of END (Macpherson et al. 2011).

"Also, given that HIIT studies typically involve 3 training sessions per week, and given current physical activity guidelines are calling for 150 min of moderate-intensity exercise per week, a comparable END training program would consist of 3 × 50-min sessions per week." (Skelly. 2014)

A 3-min warm-up at 50 W was performed prior to the main exercise bout in both, the HIIT and END trials. All trials commenced following a 10-h overnight fast (all meals were standardized for a given subject across all trials) and subjects were advised to perform no physical activity other than the prescribed exercise and normal activities of daily living for 24 h prior to each trial and over the course of the 24-h collection period. 

Figure 1: Total oxygen consumption at each measurement point (A) and over 24 h (B). CON, control; HIIT, high-intensity interval training; END, continuous moderate-intensity training; HRmax, maximal heart rate. *,p< 0.05 vs. CON; †,p< 0.05 vs. HIIT

Due to the "no breakfast" + "no other exercise" framework, the results are not per se generalizable, but it seems prudent to assume that we will see a similar "catch up" in O2 consumption after the workouts under different circumstances, as well.

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

Bottom line: The study at hand underlines hat HIIT is more than just 10 min of all out exercise. It's a metabolic trigger with long lasting consequences and a real alternative to classic "cardio" training. HIIT is time-efficient and effective, but it's not exactly resistance training compatible. The constant CNS overload you'd suffer if you add 3 HIIT sessions on the off days to a 3-day split resistance training regimen is much more likely to fry your nerves than a "lazy" walk on an incline treadmill. Keep that in mind and be weary of sleep problems, a lack of drive and motivation if you decide to incorporate additional high intensity interval work into your routine | Comment on Facebook!

Reference: 

• Macpherson, R. E., et al. "Run sprint interval training improves aerobic performance but not maximal cardiac output." Medicine and science in sports and exercise 43.1 (2011): 115-122.
• Skelly, Lauren E., et al. "High-intensity interval exercise induces 24-h energy expenditure similar to traditional endurance exercise despite reduced time commitment." Applied Physiology, Nutrition, and Metabolism 39.999 (2014): 1-4.