Science Round-Up Seconds: Vitamin E Succinate, How It's Extracted from Barley Leaves, Kills Cancer, Ramps up Growth Hormone & Spikes Prolactin. Plus: Testostosterone & Thyroid Hormone Decline Due To Plyometrics & HIIT

Regardless of all the hypocritical hoopla around his persona, Lance Armstrong has always been able to push himself like no one else. No wonder that intense plyometrics were part of his regimen.

If the SuppVersity Science Round Up was a meal, I guess you could say that Carl Lanore and I were sort of gluttonous, yesterday (click here to download the podcast, if you have not already done so). We almost raced from one topic to another and therefore all the good stuff from the list is gone already and I am a bit pressed on time to get some "private life" in, so that I am not psyched about the idea of writing about auxiliary stuff.

Against that background and in view of the fact that I felt that the pace of yesterday's show did not really leave enough room for some important details, I will stick to rehashing and expanding on the stories about Vitamin E succcinate and the detrimental effects of beating the crap out of yourself doing plyometrics or crazy HIIT workouts (too regularly), in today's installment of the SuppVersity Science Round-Up Seconds.

Let's see. Why don't we start at the end of yesterday's show?

• Vitamin E succinate the most potent anti-cancer tocopherol known to man. As you have heard on the show, vitamin E succinate attaches directly to a protein that's preferentially expressed in carcinogenic or pre-carcinogenic cells. It goes by the name α-Tocopherol-associated protein (TAP) and was found to be one of the major α-tocopherol binding proteins in serum, liver, brain and prostate. What has as of yet not been so clear, though, is that the expression of this protein increases with the malignancy of (breast) cancer (Tam. 2012). 
  
  

  

  Figure 1: Effects of alpha tocoperyl succinate alone (TOS), doxorubicin alone (DOX) or both (DOX + TOS) on cell viability in human MB231 breast cancer cells (my edits, original from Tam. 2012) - note: The effect was less pronounced in other cancer cells, so that it is reasonable to assume that the efficacy of the therapy will depend on the exact genotype of the cancer (for those tested in the study it was MB231 > SKBR3 > MCF 10A)

  When alpha tocopherol succinate binds to the protein on the cancer cells, this will either alone, or in combination with chemotherapy trigger apoptosis and cell death. It is as of yet not fully elucidated why vitamin E succinate is highly cancer-specific and leaves the healthy cells intact, but this could be related to the high metabolic rate and exuberant ROS production of cancer cells. There is however some research that would suggest that the cancer cells literally suffocate in their own radical oxygen specimen (ROS), which can no longer be cleared from the cell, due to the alpha-tocopheryl succinate induced displacement of ubiquinone from CII and the subsequent blockade of succinate dehydrogenase (SDH) activity (Dong. 2012).  If this hypothesis holds true it would therefore appear that long-term chronic supplementation with vitamin E succinate cannot be recommended until future studies on its general safety have been undertaken. As an adjuvant to chemotherapy, on the other hand, it could drastically reduce the dosage requirements during chemotherapy in specific types of cancer (see figure 1) and thus minimize side effects.
  
  You see, there is more to it than you can say in two minutes on the radio and this is why I will make sure we don't rush through the items that fast, in the next show. Ah,... of course the dietary source. I had almost forgotten about that one. As mentioned on the show, alpha tocopheryl succinate was originally extracted from Barley leaves. An while this may not be the first paper dealing with this "natural vitamin E analog", the one by Badamchian et al. is probably the one you will be most interested in.
  
  Published in the Journal of Nutritional Biochemistry the paper does not only describe the isolation of vitamin E succinate from green barley leaf extract (BLE)...
  

  "BLE [barley leaf extract] powder (50 mg/mL) was suspended in water and stirred for 1 hr at room temperature. The mixture was then centrifuged at 3000g for 30 minutes using a bench-top centrifuge. The pellet was discarded and the supernatant was pre-filtered through a Millipore DEPTH filter. The filtrate was then filtered through 0.45 I.tM mem- brane and stored at -20 ° C for HPLC or biological assays." (Badamchian. 1999)

  ... it does also shine another spotlight on its potential biological effects, as far as it's ability to increase growth hormone, but (unfortunately?) also prolactin in isolated anterior pituitary cells from female rodents:
  

  

  Figure 2: Prolactin and growth hormone release in anterior pituitary cells of female rodents after incubation with different amounts of green barley extract in which vitamin E succinate had been deterimed as the main ingredient before (based on Badamchian. 1999)

  It's really hard to estimate whether or not one of these effects would translate from a rodent cell in the petri dish to you or me popping a cap with vitamin E succinate everyday. That's particularly true in view of the fact that the underlying mechanism of the increase in GH and the imho more concerning increase in prolactin is neither mediated by increases in intracellular C-AMP, as it would be the case for GRF (old acronym for growth hormone releasing hormone), nor is it induced by the hydrolysis of polyhoshpoinositide, which is the underlying mechanism of the stimulative effect of TRH (thyrotropin releasing hormone). So basically we neither know how it works, nor do we know, whether the oral ingestion of vitamin E-succinate would be sufficient to produce serum concentrations in the pituitary that would be high enough concentrations to make any difference at all (note: the scientists excluded the influence of other components of the extract by testing alpha tocopherol succinate on its own in a separate trial)
  
  Bottom line: Based on roughly one dozen of in-vitro studies there is simply still to little evidence to decide who, outside of people with a history of cancer or someone who is just undergoing chemotherapy would benefit. Therefore, I suggest you wait before you add vitamin E succinate to your list of 'must have' supplements. Is it promising? Sure! Is it exciting, yeah! Is it save for a healthy being to be taken chronically??? I can't tell.
• The detrimental hormonal effects of pushing yourself beyond the tolerable threshold - Hardcore plyometrics and heavy HIIT and their impact on testosterone, cortisol, thyroid hormone and co: I guess you did already get the main message when you listened to the show, but just to give you an idea about the actual quantities, I thought it would be nice to provide you with two graphs as a reference.
  

  

  Figure 3: Comparison of the hormonal responses measured in the plyometrics (left) and the HIIT vs. LISS (right) study (based on Ozen. 2012 and Hackney. 2012)

  If you focus mainly on the differential cortisol responses in the two studies, it would appear likely that we are dealing with two very different forms of 'overtraining' here. While the HIIT protocol (90s at 100-110%, 90s active recovery at 40% matched for workload with steady state jogging at 60-65% of the VO2 max) probably wouldn't be a problem, if the athletes would get adequate rest and nutrition in the days after the session, the 6-weeks of plyometrics (15 session, increasing density, 90-195 reps per session) were enough to send the participants right into the vicious circle of the Athlete's Triad (if you have not done so already, I suggest you read up on that in the eponymous SuppVersity series).
  
  And you know what? Despite, or I should probably rather say due to their compromised hormone levels the guys in the plyometrics study did not lose a single gram of body weight. Good for their muscle, bad for the fat which was likewise preserved by the hormonal shut down, which affected both cortisol and testosterone in a similar way. So is that good or bad news? Well, let me say it this way:. Usually I see people training for a purpose and while the outcome often is stagnation and chronic fatigue, I would suspect that only few of you will have that on their mind, when they are hitting the gym, right?

Apropos viscous circle, and overtraining in order to avoid "overblogging" I will call it a day for today. Come back tomorrow for a couple of wholly new studies from the realms of exercise and nutrition sciences and in case you are planning to drink this evening, I highly suggest you check out the SuppVersity Facebook newspost on the effects of green tea extract on the uptake of alcohol. It may well be that those old fatburner caps of yours can be put to a way better use ;-)

References:

• Badamchian M, Spangelo BL, Bao Y et al. Isolation of a vitamin E analog from green barley leaf extract that stimulates the release of prolactin and growth hormone from rat anterior pituitary cells in vitro. Journal of Nutritional Biochemestry. 1994; 5: 145-150.
• Dong LF, Low P, Dyason JC, Wang XF, Prochazka L, Witting PK, Freeman R, Swettenham E, Valis K, Liu J, Zobalova R, Turanek J, Spitz DR, Domann FE, Scheffler IE, Ralph SJ, Neuzil J. Alpha-tocopheryl succinate induces apoptosis by targeting ubiquinone-binding sites in mitochondrial respiratory complex II. Oncogene. 2008 Jul 17;27(31):4324-35. Epub 2008 Mar 31.
• Hackney AC, Kallman A, Hosick KP, Rubin DA, Battaglini CL. Thyroid hormonal responses to intensive interval versus steady-state endurance exercise sessions. Hormones (Athens). 2012 Jan-Mar;11(1):54-60.
• Ozen, SV. Reproductive hormones and cortisol responses to plyometric training in males. Biol Sport.2012; 29 (3).
• Tam KW, Ho CT, Lee WJ, Tu SH, Huang CS, Chen CS, Lee CH, Wu CH, Ho YS. Alteration of α-tocopherol-associated protein (TAP) expression in human breast epithelial cells during breast cancer development. Food Chemistry. 2012 [ahead of print]

Breakthrough HMB Research: Additional(!) 10% Reduction in Body Fat, 5% Higher Lean Mass + 2x Higher Strength Gains After 12W of Heavy Lifting in Trained Individuals

HMB-FA could be for ladies, too - or don't you want to look good naked, girls?

First, it was "as potent as oxandrolone", then it was "disappointing", "dysfunctional" and "tasted like crap"... you know what I am talking about? Well, then you've been around in the bodybuilding and fitness community for some time. And since you are here, at the SuppVersity, your goto source for the latest information from the realms of nutrition, exercise and supplementation science, you will probably be aware, that HMB, the molecule, I have obviously been referring to in the first sentences of this article, is about to make a comback - in liquid form and without the calcium bond in calcium β-hydroxy-β-methylbutyrate the studies that were presented at the last ISSN conference (read previous article) caused quite sensation in the fitness community.

Now, more than 6 months later, I got a message from Jacob Wilson that he and his colleagues have "just published the first long term periodized HARDCORE training study using HMB-Free acid." It's, as Jacob says, and I can confirm, the "most controlled study to date" (Wilson, 2014 - Facebook).

No, soccer mums! HMB is not going to kill your kid: I am nor sure why, but whenever supplements work (best example creatine), it won't take long until the first rumors of potentially hazardous side effects appear (Fuller. 2014). First on the Internet, then on TV (see the WPXI News Item Jose Antonio posted recently on the ISSN Facebook site). Against that background it's good to know that the no-observed-adverse-event-level (NOAEL) for HMB is 2.48 and 2.83 g/kg BW d−1 in male and female rats, respectively. For a human being this would translate to ~70-100g/per day and thus certainly more than you'll be able to afford, when the free acid form of HMB will hit the market.

And after a brief with Jacob about the study design that revealed that the authors omitted the (imho critically important) information that the subjects received both HMB and a whey protein supplement (the latter is not mentioned in the methodology section), I would even agree that Jacob's conclusion that "his" study shows that HMB "clealy works in trained athletes" (Wilson, J. Facebook Conversation. 2014) is accurate as well.

Let's first take a look at what Wilson et al. did

Before we go on with the results, of which I know that they are what intrigues you most, let's briefly take a look at the pretty unique design of the combined exercise training + supplementation regimen the scientists from the University of Tampa, the IMG Acadamy, the University of Central Florida, and the Iowa State University came up with for this experiment:

• 12 weeks is the study length we are looking at -- plenty of time for muscle growth, you would say, but if you want to use trained athletes, this is probably as short as it may be to make sure that you get measureable results 

• 

  Table 1: Overview of Phase 1-3 (Wilson. 2014)

  three training phases -- with Phase 1 (Table 1, top) consisting of a daily undulating periodized
  resistance-training program 3 days per week during,  Phase 2 (Table 1, middle) 2-week
  overreaching cycle during weeks 9 and 10, and Phase 3 (Table 1, bottom) tapering (volume) for weeks 11 and 12 - needless to say that this is an intense protocol which will, even without HMB, produce serious gains
• 20 is the number of resistance trained men who participated in the study -- with 9 guys in the placebo and 11 guys in the HMB group enough to detect statistically significant differences, if those are actually physiologically relevant (in other words: a single outlier, maybe a "non-responder" - if there was such a thing - won't ruin the whole data set)
• standardized baseline tests for strength & body comp, as well as blood draws and analyses -- this is so basic that I actually thought about even mentioning it
• 3g of per day that's the dosage of HMB in a free acid form (HMB-FA) -- the free form of HMB has been shown by Fuller et al. in 2011, already, to have a superior bioavailability

There is more than just a superior bioavailability to HMB-FA! What's in fact more important than the increased relative amount of HMB that makes it into your blood stream, is the speed at which this process takes place. Improved absorption kinetics, ie. faster absorption ➲ greater anabolism - if we apply what we've learned about the difference between 30g of whey protein and a quarter-pounder, this would mean that cannot expect to see the same results with 3g and probably not even with 9g of calcium bound "regular" HMB - even if the total amount of HMB that hits your blood stream would be higher!"

• 30g of whey protein isolate (Dymatize ISO100, chocolate) that's the dosage of additional whey protein all subjects received -- this information is unfortunately missing from the original paper - a mishap that had me question the value of the data, initially; and if I had not been able to acquire it from Jacob directly, I would probably have torn the study apart, pointing to the possibility that HMB (FA or not) would produce similar non-existent results as the 3g+ of leucine people add to their whey protein shakes, falsely hoping this would increase the protein synthesis "beyond 100%"

I know the above is more than some of you want to process; so if you don't want to read it just keep in mind that we are dealing with a highly anabolic exercise protocol, which is - if anything - too intense to be considered "what the average fitness enthusiast will do in the gym". This does not change, though, that the results I plotted in Figure 1 are more representative of what the majority of you could achieve on a corresponding regimen (exercise + supplementation), than the albeit impressive results of the myriad of classic HMB studies in elderly patients (Wilson. 2008).

Figure 1: Changes in strength and body composition over the course of the 12-week study (Wilson. 2014))

Apropos, "impressive" - I should say that this attribute applies to the results Wilson et al. present in their recent paper, as well; and that's true for both, the supplement and placebo group!

"HMB-FA resulted in increased total strength (bench press, squat, and deadlift combined) over the 12-week training (77.1  ±  18.4 vs. 25.3  ±  22.0  kg, p  <  0.001); a greater increase in vertical jump power (991 ± 168 vs. 630 ± 167 W, p < 0.001); and increased lean body mass gain (7.4  ±  4.2 vs. 2.1  ±  6.1  kg, p < 0.001) in HMB-FA- and placebo-supplemented groups, respectively." (Wilson. 2014)

Whether or, the more appropriate question probably is, to which degree the superior lean and strength gains in the HMB group are a result of the blunted increase in creatine kinase (−6 ± 91 vs. 277 ± 229 IU/l, p < 0.001), an (imho) very unreliable marker of muscle damage and cortisol (−0.2 ± 2.9 vs. 4.5 ± 1.7 μg/dl, p  <  0.003), a suspected catabolic, the role of which in the orchestrate of muscle growth does yet remain highly elusive (learn more in "All About Cortisol" | read more), in the HMB-FA group during the overreaching cycle is questionable and imho of corelative, not causal nature.

Previously, HMB turned out to be particularly useful in scenarios where muscle loss was an issue (the previously mentioned studies in elderly individuals). You also know from a previous article of mine that Wilkinson et al. were able to show that HMB - contrary to leucine, by the way - an excellent inhibitor of protein breakdown. In am overreaching scenario, of which you can see based on the significant strength decreases in the placebo group at the end of the overreaching phase (see Figure 1, left), it is thus possible that the added anti-catabolic effects of HMB are what actually made the difference. In turn, this would yet mean: If you don't train like a maniac, even high amounts of additional HMB may feel to induce changes, as Jacob and his colleagues observed in the study at hand.

When is HMB-FA going to be available? As of now no supplement company has officially announced a free form HMB product (at least none I know of). Based on the hype the study at hand will certainly generate, I would yet expect that John Rathmacher, John Fuller, Shawn Baier, Steve Nissen, and Naji Abumrad who hold a patent on an "Improved method of administering beta-hydroxy-beta-methylbutyrate (hmb)" (Rathemacher. 2011), which is basically HMB-FA, will already be locked in talks with several companies.

I am impressed! By both, the study design and the results, by the way. That's the type or dietary research on dietary supplements that's done by exercise enthusiasts instead of office sitters; and it's the kind of science of which I would like to see more in the future.

That being said, let me tell you something important before you scroll down to the comment area and ask: I don't know when the first HMB-FA products are about to hit the market. All I can tell you is that I personally would not try to emulate the results with regular HMB. As I pointed out in the red box towards the top, chances that you'd see the same benefits, when you're supplementing with calcium-HMB and whey are slim and if you know how "regular" HMB tastes, you will be aware that a "test run" would probably hurt your tastebuds even more than it would hurt your purse ;-)

Reference:

• Fuller Jr, John C., et al. "Subchronic toxicity study of β-hydroxy-β-methylbutyric free acid in Sprague-Dawley rats." Food and Chemical Toxicology (2014).
• Rathemacher, John, et al. "Improved method of administering beta-hydroxy-beta-methylbutyrate (hmb)" WO 2011075741 A1. 2011
• Wilson, Gabriel J., Jacob M. Wilson, and Anssi H. Manninen. "Effects of beta-hydroxy-beta-methylbutyrate (HMB) on exercise performance and body composition across varying levels of age, sex, and training experience: A review." Nutr Metab (Lond) 5 (2008): 1.
• Wilson, Gabrial J., et al. "The effects of 12 weeks of beta-hydroxy-beta-methylbutyrate free acid supplementation on muscle mass, strength, and power in resistance-trained individuals: a randomized, double-blind, placebo-controlled study." European Journal of Applied Physiology (2014)

Two Crazy, but Scientifically Proven Workouts for You to Try if You Want to Gain Muscle While Losing Fat or Cut Your Body Fat in Half to Finally Reach a Sub 10% Body Fat Level

Don't be fooled. It takes significant effort to realize significant results.

I assume by now all of you have taken up their new workout routines for 2015. This article may thus come a bit late, but even if you are happy with your 2015 routine by now, in 6 months from now you will have to switch things up to make further progress.

Against that background it may be worth bookmarking (hit "ctrl + d") this article for later reference. I mean, results like 10% reduction in body fat, 5% increased lean mass and significant strength gains in 12 weeks" or a 50% reduction in body from 16% to 8% body fat that's something you may want to go back to in 6 months, right?

Learn more about the best muscle building exercise at the SuppVeristy

Optimizing Rest for Size and Strength Gains

Alternate Squats & BP for GAINS!

Farmer's Walk or Squat? Is Strong- men T. For You?

Full ROM ➯ Full Gains - Form Counts!

Battle the Rope to Get Ripped & Strong

Up Your Squat by 25% With Sodium Bicarbonate

• The HMB-Powered Overreaching Regimen from Wilson's 2014 study is quite extreme and will stretch any of you to his / her personal limits, but it's going to yield results... with and without free acid HMB supplementation, by the way.
  
  Since you can read all the details about the results in my previous article I am going to focus solely on the training regimen in today's SuppVersity article. So let's see: You will go through three training phases over the course of 12 weeks:

  • 

    Table 1: Overview of Phase 1-3 (Wilson. 2014)

    Phase 1 (blue), a daily undulating perio- dized resistance-training program w/ 3x full body workouts/week for 8 weeks.
  • Phase 2 (red), after you've laid the groundwork you will go through an intense 2-week overreaching phase in weeks 9 and 10, with five intense workouts per week
  • Phase 3 (green), now that you are totally fatigued you will be tapering the volume during weeks 11 and 12 to reap the benefits from the two weeks overreaching without running the risk of overtraining (=chronic overreaching with all the negative side effects described in the Athlete's Triad Series)
  I do have to warn you, though, this workout is intense and a baseline protein supplement as well as plenty of food are required to sustain a workout like this, where your workout weights are increased systematically whenever the prescribed amount of repetitions were completed. Whether you decide to copy the HMB supplementation protocol is up to you. If you want to, but don't have enough money, try to take 3x2g of regular calcium HMB instead of the pricey 3g of free-acid HMB - I am pretty sure that's going to work, too.
• The crossfit-esque 10-week workout from a 2013 study by Smith et al. (2014), which did shed an extra 8% of body fat of the already lean frames of the 16% body fat participants of the respective study (read more about the results).
  
  If you want to try it, you'd have to follow a crossfit-based high intensity power training (HIPT) program using basic gymnastic skills (handstands, ring, and bar exercises) and traditional multiple-joint, functional, resistance exercises (squat, press, deadlift, Olympic lifts) performed as quickly as possible at a high intensity (low repetition, high percentage of 1-RM).
  

  

  Table 2: Two representative weeks of the training program, click here to see the rest (Smith. 2014).

  You obviously don't have to copy the subjects and perform all your training sessions at a CrossFit affiliate gym, but you would be well-advised to hire a trainer if you don't know how to perform the exercises listed in Table 2. You will do workouts in which you will perform a given number of sets / reps as fast as possible and workouts where you have to perform as many reps/sets as possible in a given amount of time ranging from 10-20 minutes. Practically speaking this means you are competing against your personal best on every exercise in every workout.
  
  In contrast to the strength/skill portion of the exercise session, where you won't have a prescribed recovery time, the WOD sessions require you to complete all the exercises as quickly as possible with no prescribed rest period (yes, this means you rest only so long to make sure you don't pass out). You can review the full workout program here, but I guess you would even see results if you simply did the workouts outlined in Table 2 in an A / B style for 10 weeks.

Crossfit is highly injury prone - even if a trainer is present. When a trainer is present only "some times" to watch what the trainees are doing, however, the injury rates are two times higher (32% vs. 15%) than when a trainer  is present "all of the time". That's at least what an impressive 2014 study from the University of Rochester School of Medicine and Dentistry in 486 men and women workout out in crossfit gyms indicates (Weisenthal. 2014).

A word of caution: I have to warn you. Neither the Wilson nor the Smith workout is suitable for rookies. With the Wilson workout you may easily run from the 2-week overreaching into a chronic overtraining phase as a rookie - specifically if you don't know your own limits and fall for the common mistake that "doing more helps more". Stick to the two weeks of 5x/week workouts and don't tell yourself that you could sustain another week of overreaching and wouldn't need the tapering phase and/or repeat the same cycle right away. That's a 12-week intervention after which you should return to a "normal" workout routine and repeat it no sooner than 2 months later.

Similarly, the crossfit-esque workout from the Smith study should (a) not be done by people who are still struggling with their their O-lifting techique and/or (b) are not already well-conditioned. And this is no arbitrary "disclaimer". Studies show that the mean injury rate in CrossFit is approximately 20%. In that, males who usually cannot leave their egos at the door are significantly more likely to sustain an injury than females | Comment on Facebook!

References:

• Smith MM, Sommer AJ, Starkoff BE, Devor ST. Crossfit-based high intensity power training improves maximal aerobic fitness and body composition. J Strength Cond Res. 2013 Feb 22.
• Weisenthal, Benjamin M., et al. "Injury rate and patterns among CrossFit athletes." Orthopaedic Journal of Sports Medicine 2.4 (2014): 2325967114531177.
• Wilson, Gabriel J., et al. "The effects of 12 weeks of beta-hydroxy-beta-methylbutyrate free acid supplementation on muscle mass, strength, and power in resistance-trained individuals: a randomized, double-blind, placebo-controlled study." European Journal of Applied Physiology (2014).

24 HIIT Workouts in Three or Eight Weeks? Net Effects on VO2Max Are Almost Identical, But Occur at Different Times

In general, you have to count and limit your weekly HIIT sessions. Doing as much as humanly possible, could yet make sense, when you're preparing for Olympia 2016 and realize 5 weeks before the event that you have been lingering for too long ;-)

I think as a SuppVersity reader you know by now that "more won't yield more" - no matter if we are talking about supplements or exercise. Now, while we've had countless examples of the "more ain't more" principle that's also at the heart of the "Three Simple Rules of Supplementation" (read article) for supplements (e.g. zinc, chromium, etc.) and the simple notion that eating less won't always result in greater weight loss, evidence for the pro-anabolic / adaptive effects of exercise in general, and non-steady state cardio, in particular is scarce. Against that background it's all the more important for us to cherish the publication of a paper from the Norwegian University of Science and Technology and the St Olav University Hospital in Trondheim Norway, Roy told me about by messaging me via the SuppVersity Facebook Page.

"More HIIT doesn't help more, either"

I guess the above would be the elevator pitch for the mythical "turbo lift" in Star Trek. For someone like yourself who has learned never to swallow "expert" wisdom just like that, the statement "more HIIT doesn't hep more, either" obviously won't be satisfying.

Figure 2: Illustration of the training in the low frequency (LF) and high frequency (HF) group.

If you look at the illustration above, you will already know somewhat more about the "more" in the previous sentence. As you can see, the parameter that has been modified is not the volume, it's the frequency!  - and thus one of the parameters of which many gymrats think that it could hardly be high enough (AM + PM training, 7 days a week - does that ring a bell?). What this people ignore is the simple truth that ...

... adapatation takes time and training more often does not accelerate this process!

In the end, I am actually quite surprised to see that the net VO2 "gain" the scientists measured in the subsequent detraining phase (see Figure 2) was identical. Or, more explicitly, that packing 24 training sessions into three weeks did not blunt the mitochondrial adaptation processes that are responsible for the increase in VO2max, altogether.

Figure 2: VO2max and heart rate values of the 16 healthy subjects before / after high vs. low frequency HIIT (Hatle. 2014)

If we are brutally honest, though, there is obviously an advantage for the 24 sessions in 8 weeks version of this training protocol (see Figure 3, as well). The VO2max scores were after all identical only in the "catch-up" up period in week 11 and due to the rapid decline after week 12 the benefits faded equally rapid in both groups when the 19 healthy, normalweight, but non-athletic subjects returned to their usual laziness (detraining = not training at all).

Figure 3: If time is an issue, it's probably worth to overreach for 3 weeks and compete after two weeks of "intense" detraining (Hatle. 2014)

Bottom line: If you are pressed in time, a short phase of very frequent training can bring your conditioning up faster (5 weeks vs. 6 weeks; see Figure 3). For an athlete who may react slightly different to this kind of protocol than the average Joes in the study at hand this one week could decide victory or defeat.

For someone who is in this for life - a true physical culturist, so to say - HIITing it everyday is not just madness, it is also very likely to end up producing the previously hinted at detrimental performance (and later on health) effects, as soon as this brief episode of overreaching becomes and endless nightmare of overtraining.

References:

• Hatle H, Støbakk PK, Mølmen HE, Brønstad E, Tjønna AE, et al. "Effect of 24 Sessions of High-Intensity Aerobic Interval Training Carried out at Either High or Moderate Frequency, a Randomized Trial." PLoS ONE 9(2). (2014): e88375. doi:10.1371/journal.pone.0088375