Showing posts with label men. Show all posts
Showing posts with label men. Show all posts

Wednesday, April 13, 2016

Longer Rest Periods Compromise Adaptational Response in Resistance Training Older Men in 12 Week Study

Best-agers listen up: If you want to make progress, socialize after your workouts and stick to rest periods in the 60-90s range.
Best-agers, listen up! If you are the kind of person who likes to chat for four minutes between his / her sets you are not just wasting time. You are also making your workouts less effective. While there is little evidence that there are major differences between rest times of 60s and 90s, a recent study from the Division of Biokinesiology and Physical Therapy at the Clinical Exercise Research Center of the University of Southern California is not the first study to suggest that resting longer than maximally 120s is going to compromise the changes in body composition, muscular performance, and functional performance that occur in response to resistance training.

I have to admit, with a mean age of 70.3 years, the 22 male volunteers of said study dont qualify as the "classic" gymrat. On the other hand, you will probably have heard the argument that aging muscle cannot sustain the same extent of high intensity hammering thats highly productive in younger folks against.
Learn more about building muscle at www.suppversity.com

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Pre-Exhaustion Exhausts Your Growth Potential

Full ROM ? Full Gains - Form Counts!

Battle the Rope to Get Ripped & Strong

Study Indicates Cut the Volume Make the Gains!
Against that background, its actually all the more surprising that the 11 men in the 60s rest period groups of this recent 4 weeks resistance training study saw significantly greater increase in lean muscle mass, bench press & leg press 1RM max, performance on the pull-down and several parameters of functional performance (not shown in Figure 1).
Figure 1: Changes in body composition and strength after 8 and 12 weeks; expressed relative to the values that were measured after the 4-week pre-training phase that was identical for both groups (Villanueva. 2014)
Except from the rest times, the periodized strength training regimen was 100% identical for both groups. This means that all 22 study subjects performed the same progressive total body resistance training program which was preluded by a 4-week familiarization protocol that was 100% identical for both groups:
  • Training frequency: 3 days/week for the 4-week training cycle
  • Sets / reps: 2 to 4 sets with 15 to 8 repetitions (set number increased, rep number decreased over time)
  • Exercise number: Four to six exercises per workout
Only after the subjects had completed the first four weeks of training they were paired based on the similarity of their flat bench machine chest press 1-RM and randomly placed into one of the two groups: The SS = short (60s) and the SL = long (240s) rest group. As the scientists say they chose
"this strength outcome measure, because previous work from our lab has indicated there is relatively less variability among study participants with chest press 1-RM val ues, versus leg press 1-RM values, and, therefore, it would allow us to more easily randomize and create two treatment groups that are similar in (upper body maximum) strength.
In the following 8-week actual study period the subjects were subjected to a progressive total-body resistance training program emphasizing development of upper and lower body strength.
  • Training frequency: 3 days/week for 8 weeks by both groups (SS and SL)
  • Sets / reps: sets ranged from 2 to 3, repetitions from 6 to 4
  • Exercise number: 4–6 exercises
During this active study period, the only difference in program design between the two strength RT groups in was the rest interval length utilized between sets: 60 s (SS group) versus 4 min (SL group).
"Throughout the entire resistance training program, all sets were performed maximally for the assigned number of repetitions and with proper lifting technique, and loads were adjusted in accordance with recovery and performance, across the repeated sets progression.
At least in untrained subjects shorter rest periods (60s vs. 150s) may have more beneficial effects on body composition, i.e. they elicit greater lean mass gains and higher losses of body fat (Buresh. 2009)
What about studies in younger subjects? The results are not consistent, but generally speaking there appears to be slight advantage in terms of strength gains with rest periods in the 90s-150s range as they were observed by Robert Buresh et al. (2009) in healthy, recently untrained males. In previously strength-trained men the benefits appear to vanish, when the total exercise volume is not controlled for, though (Willardson. 2008). Moreover, the previously cited study by Buresh et al.  (2009) indicates that shorter rest periods will elicit more favorable changes in body composition (see Figure on the left). We must be careful, though - short is not generally better.  A review by de Salles et al. (2009) indicates that rest periods below 60s can impair the strength gains and while respective data is lacking, it is likely that this will also have negative effects on the amount of lean mass you will gain on otherwise identical training regimen.
Furthermore, it is important to note that study participants were never expected to perform sets to absolute muscular failure; given an appropriate loading progression, with alterations in set/repetition schemes throughout and across microcycles (i.e., a series of 3 training sessions), the repetition maximum assignments allowed for successful completion of the assigned number of repetitions at the load(s) prescribed, across multiple sets, and with minimal need for assistance/spotting" (Villanueva. 2014.)
Now this certainly sounds as if the protocol was realistic. But there is one major difference that puts a question mark behind the results of the study: usually regimen with long and short rest times differ significantly in the number of sets and the number of reps. Thus it is possible that future studies using different protocols for both groups would yield different results.
Figure 2: More helps more... at least in elderly study subjects increasing the intake of whey protein after a workout from 20g to 40g will yield significant benefits (Yang. 2012).
Bottom line: The study at hand certainly supports previous evidence that older men and women dont necessarily have to train with the "handbreak firmly fixed". The relatively large increase in strength and functional performance, however, stand in stark contrast to the pathetic increase in lean mass. And the standardized set and rep ranges make it impossible for the 240s rest group to benefit from the ability to train at higher volumes.

Another thing that is wirth mentioning is that the subjects consumed >1.0 gram protein/kilogram body weight/day - without the addition of fast absorbing high BCAA protein sources, however, elderly men (and women) are always having a hard time to build practically relevant amounts of lean muscle.

Against that background, I would love to see this study being repeated with 30-40g of whey protein being consumed in the vicinity of the workout; and in case you want to do your own N=1 experiment using this or any other workout protocol described in the study at hand, I would suggest you make sure to add some extra-protein, as well. Previous studies do after all indicate that "more" as in 40g vs. just 15-20g helps more in men and women in their 60s or older | Comment on Facebook!
References:
  • Buresh, Robert, Kris Berg, and Jeffrey French. "The effect of resistive exercise rest interval on hormonal response, strength, and hypertrophy with training." The Journal of Strength & Conditioning Research 23.1 (2009): 62-71.
  • de Salles, Belmiro Freitas, et al. "Rest interval between sets in strength training." Sports Medicine 39.9 (2009): 765-777.
  • Villanueva, Matthew G., Christianne Joy Lane, and E. Todd Schroeder. "Short rest interval lengths between sets optimally enhance body composition and performance with 8 weeks of strength resistance training in older men." European journal of applied physiology (2014): 1-14.
  • Willardson, Jeffrey M., and Lee N. Burkett. "The effect of different rest intervals between sets on volume components and strength gains." The Journal of Strength & Conditioning Research 22.1 (2008): 146-152.
  • Yang, Yifan, et al. "Resistance exercise enhances myofibrillar protein synthesis with graded intakes of whey protein in older men." British Journal of Nutrition 108.10 (2012): 1780-1788.


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Thursday, March 31, 2016

Physical Cognitive Exercise Are Similarly Effective DNA Protectors Antioxidant Boosters in Elderly Men Women

Brain builders and muscle builders are similarly effective DNA protectors in the elderly.
As a SuppVersity reader you wont be surprised to hear that Bernhard Franzke and his colleagues from the University of Vienna were able to confirm that resistance training can improve the resistance of human DNA to H2O2 damage in institutionalised elderly. What may be news to you, though, is that very similar effects can be achieved by cognitive training in form of coordinative or cognitive tasks that were performed only two times per week by the 105 institutionalised elderly women and men (aged 65–98 years) the scientists recruited from five different senior residences in the area of Vienna (Franzke. 2014).
DNA damage is obviously important, maintaining optimal lean mass levels is important, too

Tri- or Multi-Set Training for Body Recomp.?

Alternating Squat & Blood Pressure - Productive?

Pre-Exhaustion Exhausts Your Growth Potential

Full ROM ? Full Gains - Form Counts!

Battle the Rope to Get Ripped & Strong

Study Indicates Cut the Volume Make the Gains!
In the recent Austrian study, the subjects had been randomized to three groups. The previously described cognitive training group, which also served as a "control", as well as two resistance training groups.
"The RT groups (RT and RTS) performed two sessions of RT per week, supervised by a sport scientist, conducted on two non-consecutive days. Training attendance was recorded every session. The only equipment used was exercise bands and a chair. [...] The main part consisted of 10 exercises for the main muscle groups (legs, back, abdomen, chest, shoulder and arms). One training session started with 10 min of warm-up, continued with 30–40 min of strength training and ended with a 10-min cool-down. To keep the training stimulus high enough, the exercise program was adjusted to the participants’ individual needs, by either adapting the resistance of the elastic band (shorter or stronger band) or by modifying the exercise, by means of performing a more diffiult version. In the initial phase (4 weeks) one set of 15 repetitions was performed in order to learn the correct form of each exercise. From the fifth week on, the intensity and volume were progressively increased from two sets of light exercises to two sets of heavy resistance. If the participants could easily perform two sets of 15 repetitions they were told either to take more resistance or to perform a more difficult version of the exercise" (Franzke. 2014).
In contrast to the RT group, which did "nothing", but the previously described resistance training regimen, the subjects in the RTS group consumed a multi-ingredient supplement every morning, as well as directly after each training session. Said supplement consisted of 20.7g protein [56 energy (En) %, 19.7g whey protein, 3 g leucine, >10 g essential amino acids], 9.3 g carbohydrates (25 En%, 0.8 BE); 3.0 g fat (18 En%), 1.2 g roughage (2 En%), 800 IU (20 ?g) of vitamin D, 250 mg calcium, vitamins C, E, B6 and B12, folic acid and magnesium (one portion FortiFit, Nutricia with a total energy content per drink of only 150 kcal).
Figure 1: Changes in parameters of DNA damage and antioxidant enzyme expression (Franzke. 2014).
In spite of the fact that the intake of the nutritional supplement was controlled at breakfast as well as after the training sessions, it did not provide significant additional benefits on top of the regular resistance training protocol.

We should keep in mind, though, that (a) non-significant benefits were visible for the formamidopyrimidine DNA glycosylase (FPG) and the expression of superoxide dismutase and that (b) the actual benefits of protein supplements would have become visible only if the scientists had accessed the changes in body composition, as well.
Maximal protein synthesis - How much protein do the elderly need? Find out in a previous SV article.
Bottom line: If you dont have a present for your grandpa or grandma, yet, I suggest you craft a voucher for 2 weekly resistance training and cognitive training sessions with yourself as a trainer and buy a tub of protein to round your present off...

All Christmas jokes aside, the study at hand simply confirms what the proverb "a rolling stone gathers no moss" implies. Exercise, no matter whether its cognitive or physical exercise, protects aging men and women from pro-cancerous DNA damage and ensures that can maintain "a sound mind in a sane body" | Comment on Facebook!
References:
  • Franzke, B. et al. "The impact of six months strength training, nutritional supplementation or cognitive training on DNA damage in institutionalised elderly." Mutagenesis (2015):147–153.


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Thursday, March 10, 2016

Vitamin D3 Supplementation for Older Men Women Done Right Dietary Fat Can Increase the Bioavailability by 30

Taking vitamin D pills on their own may be less effective than taking them with a meal containing 30% of the calories from fat - at least for older men & women and high doses of vitamin D3
This is science. Only 6 months ago, I wrote in an article about the effects of fat on the absorption and bioavailability of fat soluble vitamins that vitamin D would be the fat soluble vitamin with the lowest dependence on the co-administration of fat. Rather than the amount, it appeared as if the change in plasma 25OHD (nanograms per milliliter) during vitamin D supplementation was rather associated with the types of fat, i.e. MUFA = increased absorption vs. PUFA = decreased absorption (Niramitmahapanya. 2011).

Now, half a year later, it appears as if another, previously overlooked variables would force me to reformulate previous recommendations: Age and dosage!
There are many ways to get your vitamin D learn more the SuppVersity

How Much To Take?

Leucine, Insulin & Vitamin D

Vit. D Speeds Up Recovery

Overlooked D-Sources

Vitamin D For Athletes!

Vitamin D Helps Store Fat
In contrast to previous studies, Bess Dawson- Hughes and colleagues investigated the influence of fat on the absorption of vitamin D3 in older, not young men and women. In that, inclusion criteria for the study were
  • no use of not more than 400 IU vitamin D or 1,000 mg calcium per day,
  • serum 25(OH)D level in the range 20 to 29.5 ng/mL (49.9 to 73.6 nmol/L),and
  • a body mass index in the range 20 to 29.5 (normal weight)
Subjects with kidney problems, hypercalcemia, general issues with malabsorption, Crohn’s disease, disorders of bone metabolism, kidney stones, cancer and those who were using proton pump in hibitors, lipid-lowering medications, fish oil, or flaxseed oil, hormones, osteoporosis medications, or high-dose thiazide diuretic therapy were equally excluded as those subjects who attended tanning salons, regularly.
Its important that the subjects were lean, because (a) the serum vitamin D response may be attenuated by D-storage in the fat tissue and (b) previous studies show that "[o]besity-associated vitamin D insufficiency is likely due to the decreased bioavailability of vitamin D3 from cutaneous and dietary sources because of its deposition in body fat compartments" (Wortsman. 2000).
This was yet not the only difference. Next to the subjects age, the amount of vitamin D3 in the capsules the subjects received differed, as well. While previous studies that reported little to no effect of fat on the absorption of vitamin D3 used small(er) amounts of vitamin D, like 1,000, 2,000 or 5,000 IU per serving, Dawson-Hughes et al. used a single serving of 50,000 IU(!) and thus more than 10x higher dosages than previous studies.
Figure 1: Composition of the test breakfast, lunch, and dinner meals, expressed as % of total energy the 50 healthy older adults consumed in the study at hand (Dawson-Hughes. 2014)
Alongside said vitamin D3 super-dose all 50 subjects ingested one out of three randomly selected meals that were either fat free or contained 30% of the total calories in form of dietary fat - albeit at two different PUFA:MUFA ratios (see Figure 1)
"[The m]eals were provided by the metabolic kitchen and consisted of real food. For example, breakfast consisted of egg whites flavored with small amounts of onion and tomato, fruit, toast, and cranberry juice. The groups were balanced for energy by adjusting the amount of sugar in the cranberry juice (diet or regular juice or a mixture of the two). Protein and fiber were balanced across all groups. MUFA:PUFA was manipulated by adding varying amounts of MUFA (olive oil) and PUFA (corn oil) to achieve a ratio of 1:4 in the low and 4:1 in the high MUFA:PUFA diets. The boxed lunch and the dinner provided to the study subjects on the test day had fat/protein/carbohydrate content similar to that of the test breakfast meals.
Importantly, the subjects were required to (a) eat all of the food provided and (b) refrain from pigging out on anything that was not on the menu for the study day.
Figure 2: Serum vitamin D3 levels in subjects after consuming fat-free or -containing meals (Dawson-Hughes. 2014)
What the scientists found, when they analyzed the vitamin D response of the subjects depending on (a) the fat content and (b) the type of the fat, Dawson-Hughes et al. found:
  • In analyses of vitamin D absorption at baseline and the three follow-up time points, there was a significant interaction of fat-free vs fat-containing meal group with time (P < 0.001). As shown in [figure 2], there was no significant difference in plasma vitamin D-3 levels at baseline, but the fat-containing meal group had significantly higher plasma vitamin D-3 concentrations than the fat-free meal group at each time point thereafter.

    At 12 hours, the fat-containing vs fat-free meal mean difference in plasma D-3 concentration was 26.9 ng/mL (95% CI 9.6 to 44.1 ng/mL) (69.9 nmol/L). Differences at the other time points were for 10 hours, 30.5 ng/mL (95% CI 14.4 to 46.7 ng/mL) (79.3 nmol/L) and for 14 hours, 21.3 ng/mL (95% CI 4.6 to 37.9 ng/mL) (55.4 nmol/L).
Keep in mind: Actually, we dont really care about the amount of vitamin D3 in the blood that was measured in the study at hand. What we care about is the impact on the 25-OHD levels and the latter were not tested in the study at hand. Previous studies suggest that using large boluses of vitamin D3 are suboptimal to achieve this goal. Against that background the study design of the study at hand, was not really optimal and didnt access the practically most relevant outcome.
  • Vitamin D-3 levels at 12 hours after the dose were 116.0 3 ng/mL (301.5 nmol/L) in the low MUFA:PUFA group and 104.2 ng/mL (270.8 nmol/L) in the high MUFA: PUFA group.

    Potential covariates, body mass index, total body fat mass, and screening plasma 25(OH)D level were not associated with vitamin D absorption and neither modified the effect of fat on vitamin D absorption.
As the researchers point out, "[t]here were no serious adverse events during the study" and "[c]ompliance with the vitamin D supplement was 100%" (Dawson-Hughes. 2014). So, non of these obvious, but undesirable confounding factors could explain the observed differences between (a) the non-fat vs. fat-meals and (b) the influence of the PUFA:MUFA ratio.
Read more about the influence of dietary fat on the bioavailability of vitamin A, D, E & K in "Vitamin A, D, E & K - How Much and What Type of Fat Do You Need to Absorb These Fat Soluble Vitamins?" more
Bottom line: Since both, age and dosage may be the confounding factors that explain the obvious difference to previous studies, I suspect that the amount of vitamin D3 is the major culprit, here. With lower doses of vitamin D3 being administered chronically, the results may well have been different - specifically with respect to their effect on serum 25OHD levels, which were unfortunately not assessed in the study at hand | Comment on Facebook!

Furthermore, the previously conducted studies used low not, no-fat meals. Against that background it appears prudent to consume your vitamin D supplements with your meals... and, you are not still eating "no-fat meals", are you?
References:
  • Dawson-Hughes, Bess, et al. "Dietary Fat Increases Vitamin D-3 Absorption." Journal of the Academy of Nutrition and Dietetics (2014).
  • Niramitmahapanya, Sathit, Susan S. Harris, and Bess Dawson-Hughes. "Type of dietary fat is associated with the 25-hydroxyvitamin D3 increment in response to vitamin D supplementation." The Journal of Clinical Endocrinology & Metabolism 96.10 (2011): 3170-3174. 
  • Wortsman, Jacobo, et al. "Decreased bioavailability of vitamin D in obesity." The American journal of clinical nutrition 72.3 (2000): 690-693.


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Sunday, February 28, 2016

Study Confirms Acute Post Exercise Myofibrillar Protein Synthesis Is Not Correlated with Resistance Training Induced Muscle Hypertrophy in Young Men

FSR ? more muscle = no news for ya!
For the average SuppVersity reader the sentence "Acute Post-Exercise Myofibrillar Protein Synthesis Is Not Correlated with Resistance Training-Induced Muscle Hypertrophy in Young Men" is not just the title of a recent paper in the open access journal PLOS|ONE, its also the experimental verification of a claim Ive made in almost all my articles about the acute effects of certain training modalities and/or supplements on myofibrillar protein synthesis and the corresponding increases in muscle size some people appear to expect from a 2h-long 10% increase in fractional protein synthesis (learn more).

And yes, practically speaking these findings imply that we have to question the real world significance of all the neat studies on the "superior muscle building effects" of whey protein, BCAAs and even more so leucine, in which the authors base their recommendations on acute increases in post-exercise protein synthesis.
Dont worry, you have not been "wheysting" your money: While there is a paucity of data to confirm the long(er) term muscle building effects of isolated amino acids (EAA, BCAA and leucine), there is plenty of data from 6-12 week human trials to support the pro-anabolic effects of whey protein. What we dont have, though is evidence to support the notion that the long-term muscle building effects are as superior to those of other protein sources (e.g. casein) as the increases in acute protein synthesis would suggest.
In the corresponding experiment that was funded by the National Science and Engineering Research Council (NSERC) of Canada Cameron J. Mitchell et al. determined whether the acute myofibrillar protein synthesis measured acutely in training-naive subjects after their first bout of resistance exercise with protein consumption would correlate with the actual increase in muscle size after 16 weeks of resistance training.

Suggested read: "Protein Intake & Muscle Catabolism: Fasting Gnaws on Your Muscle Tissue and Abundance Causes Wastefulness " | more
Before the actual experiment began, the subjects, healthy young recreationally active normal-weight men (177 cm; body mass index = 26.4 kg/m²; men age 22 years) without previous strength training experience, underwent a magnetic resonance imagining (MRI) scans of their right thigh to determine muscle volume, a dual, energy x-ray absorptiometry (DXA) scan to assess whole body fat and bone-free mass (lean mass) and standardized strength tests to determine their maximal isotonic strength (often labeled the 1RM) for all training exercises.

After all baseline measurements (including baseline muscle protein synthesis) were recorded, the subjects completed 16 weeks of RT while ingesting a protein rich beverage (30g of the same whey protein of which Burd et al. showed in 2012 that it elicits a higher increase in MPS than casein) immediately after their exercise session and with breakfast on non-training days.
"Briefly, participants trained four times weekly with two upper and two lower body workouts. Lower body exercises are described above in the acute exercise session. Upper body exercises consisted of chest press, shoulder press, seated row, lat pulldown, bicep curl and tricep extension. The program was progressive in linear manner moving from 3 sets of 12 repetitions to 4 sets of 6  repetitions. At the end of the training period, MRI, DXA scans and strength testing were repeated." (Mitchell. 2014)
If you look at the above description of the workout (and supplementation regimen) you will probably agree that this is pretty much what the majority of resistance physique oriented gym-goers do.
Figure 1: Myofibrillar fractional protein synthesis rate (left) measured acutely after a single workout and changes in muscle volume (%) over the whole 16-week study period as a function of the 1-6h post-workout FSR (Mitchell. 2014).
People who hope that the often reported increases in fractional protein synthesis would pay off and yield increased net muscle gains and thus exactly what Mitchell et al. did not observe in their study, which could not establish the corresponding correlation between the actute increase in post-workout fractional protein synthesis (Figure 1, left) and the chronic change in muscle volume (Figure 1, right).

Figure 2: Changes in muscle volume (%) expressed relative to acute increases in 4E-BP (Mitchell. 2014).
If anything, it was the expression of the Eukaryotic translation initiation factor 4E-binding protein 1 aka 4E-BP1 one of the motors of protein synthesis, but not the increase in myofibrillar fractional protein synthesis that looked as if it could have any predictive value with respect to the increase in muscle volume, the young men experienced in the course of the 16-week training period.

After thinking about the implications of these findings for a minute, I do yet have to admit that the assumption that this would refute the previously invoked recommendations completely, is probably premature.
SuppVersity Suggested Read: "Protein Wheysting?! No Significant Increase in PWO Protein Synthesis W/ 40g vs. 20g Whey, But 100% Higher Insulin, 340% More Urea & 52x Higher Oxidative Amino Acid "Loss" | more
"Though shalt not make quantitative predictions about long(er) term muscle gains based on acute FSR measurements!" - This statement is unquestionably correct. Its something I have written about before and its a statement that is supported (if not confirmed) by the data of the study at hand.

The statement "though shalt not make qualitative predictions about long(er) term muscle gains based on acute FSR measurements", on the other hand, would yet be unwarranted and is probably incorrect. We do after all have more than enough evidence that increases in post-workout protein synthesis will (sooner or later) result increases in muscle size. The fact that we cannot predict the extent of long(er) term hypertophy effects based on measuring acute changes in FSR does not imply that these changes would not matter at all. It does only mean that we have to be careful about overestimating the real-world effects of differences in protein synthesis between training modalities and supplements, even if they are statistically significant in the hours after a workout.
Reference:
  • Burd, Nicholas A., et al. "Greater stimulation of myofibrillar protein synthesis with ingestion of whey protein isolate v. micellar casein at rest and after resistance exercise in elderly men." British Journal of Nutrition 108.06 (2012): 958-962.


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Wednesday, February 17, 2016

High or Low Intensity Running Whats Better for the Heart of Untrained Men When the Energy Exp is Identical

It takes some effort to avoid making the transition from the sofa to the ICU.
Whats better for heart disease protection - high or medium intensity exercise as it is still prescribed by the majority of doctors? A recent study from the University of Erlangen-Nürnberg (Germany) probed the effects of high vs. moderate intensity training on cardiovascular risk markers of 81 untrained, healthy not exactly lean (BMI 27.2kg/m²) men aged 30-50 years.

The subjects were randomized to either a high intensity interval training or a moderate intensity steady state training group who burnt the exact same amount of energy during their workouts.
You can learn more about HIIT at the SuppVersity

Add 2lsb of Lean Mass in 3 Weeks

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 Aint For Everyone
In contrast to other studies, the groups did not train at the same time. The study started in September. From September to December, the HIIT group performed high intensity interval training
  • at 80-100% of their maximal heart rate during 90s-120min intervals,
  • with 1-3 min pauses at 70-75% of the maximal heart rate
so that 40% of the total training volume were performed at high heart rates, 35% at maximal heart rates, and 25% of the total volume at 25% of medium heart rates.
Figure 1: Overview of the study protocol (translated from Kemmler. 2015).
During the first three months, the medium intensity steady state group (MIST) group served as sedentary control (see Figure 1). A control group in which the markers of cardiovascular health rather deteriorated than improved.
Figure 2: Changes in left ventricular myocardial mass (LVMI), cardiovascular fitness (CV), intima-media thickness (IMT, associated with increased CVD risk), body fat, and lean mass (Kemmler. 2015).
What is of interest is thus not really the difference between the control and the HIIT group, but the difference between the HIIT and MIST group. A difference of which the data in Figure 2 indicates that there was a significant advantage of doing HIIT vs MIST training - at least as far as the cardiovascular disease markers are concerned.

What may come as a surprise is that despite the significant improvements in fitness and metabolic disease scores (-2.06 pts vs. -1.6 pts with HIIT vs. MIST, respectively), the amount of fat lost was more pronounced in the MIST group; and that in spite of the fact that they performed only 5% of their training at the maximal heart frequency, 10% at high intensities and the vast majority of exercise, i.e. 85%, at a moderate exercise intensity. In view of the fact that the design of the study required that all participants expended the same amount of energy, its quite interesting that the subjects in the MIST study burned more body fat than the subjects in the HIIT study. In the absence of a strictly controlled energy intake, its yet no reliable evidence that would disprove the rule that HIIT is - specifically for leaner folks - the more effective fat burner. The result of the study at hand should thus not be overrated.
Isnt high intensity training dangerous for those with heart disease? Its certainly not useful for everyone, but scientific evidence suggests that performing at high individual heart rates is beneficial and safe for cardiac rehabilitation patients (Beniamini. 1999; Warburton. 2005; Tinkham. 2014)
Figure 2: Endothelial function measured as FMD (left); maximal oxygen uptake (right) before and after 12-week high intensity interval or moderate intensity steady state exercise in patients with heart failure (Wisløff . 2007)
Before I get to the conclusions, I would like to point out that having a exisiting heart condition is not necessarily a reason to refrain from high intensity exercise. On the contrary, a 2007 study by Ulrik Wisløff et al. clearly indicates that aerobic interval training is superior to moderate continuous training even in heart failure patients. More specifically, the scientists from the Norwegian University of Science and Technology in Trondheim found that "[e]xercise intensity was an important factor for reversing LV remodeling and improving aerobic capacity, endothelial function, and quality of life in patients with postinfarction heart failure" (Wisløff. 2007).

Yet in spite of the fact that the researchers  highlight that their results would have "important implications for exercise training in rehabilitation programs" - the impact on the real world prescriptions in such programs is negligible.,
Bottom line: When it comes to heart health, the study at hand confirms that HIIT is significantly more effective than classic "cardio" training aka moderate intensity steady state (MIST). From a health perspective practitioners should thus finally stop advising their patients and clients to do hours of low or moderate intensity cardio.

2002 meta-analysis confirms: High intensity = high, medium intensity = medium reduction in CVD risk (Tanasescu. 2002).
"No effort, no results" - Its not that extreme, but doing high intensity interval training is unquestionably significantly more time efficient and as the lowe(er) drop out rates in the HIIT group show, very well doable.

What I am not sure about is whether it was a good idea to use intervals of different lengths with durations of 90s-12min. At least to me this sounds as if it was prone to overtax the CNS and increase the risk that clients will fall of the bandwagon. Furthermore, previous studies suggest that short(er) intervals are also effective. It is likewise questionable if the standardization for identical energy expenditures that lead to an increase in the HIIT volume is necessary. As it is the case with the long sprint durations, I doubt that this is actually necessary | Comment on Facebook!
References:
  • Beniamini, Yael, et al. "High-intensity strength training of patients enrolled in an outpatient cardiac rehabilitation program." Journal of Cardiopulmonary Rehabilitation and Prevention 19.1 (1999): 8-17.
  • Kemmler, Wolfgang, et al. "Hoch-versus moderat-intensive Laufbelastung–Einfluss auf kardio-metabolische Risikogrößen bei untrainierten Männern." DMW-Deutsche Medizinische Wochenschrift 140.01 (2015): e7-e13.
  • Tanasescu, Mihaela, et al. "Exercise type and intensity in relation to coronary heart disease in men." Jama 288.16 (2002): 1994-2000.
  • Tinkham, Michelle. "Health Promotion in Cardiac Rehabilitation Patients through the Use of a High-Intensity Interval Training Protocol." World Journal of Cardiovascular Diseases 4.10 (2014): 493.
  • Warburton, Darren ER, et al. "Effectiveness of high-intensity interval training for the rehabilitation of patients with coronary artery disease." The American journal of cardiology 95.9 (2005): 1080-1084.
  • Wisløff, Ulrik, et al. "Superior cardiovascular effect of aerobic interval training versus moderate continuous training in heart failure patients a randomized study." Circulation 115.24 (2007): 3086-3094.


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