Polarized Concomitant Training - Will it Help You Make Max. Gains & Improvements in Body Comp. W/ Strength+Cardio?

Polarized Concomitant Training - Will it Help You Make Max. Gains & Improvements in Body Comp. W/ Strength+Cardio?

bench press build muscle cardio concomitant training gain muscle lose fat polarized training squat strength strength training training workouts

Polarized training? Find out more...

Does concurrent / concomitant training intensity distribution matter? Unless you're a first timer at the SuppVersity you will have read at least two or three previous articles of mine about studies investigating the effects of concurrent training, i.e. the combination of strength and cardio training, (i.e. concomitant training) here.

If you recall the results, you will know that previous research has demonstrated the influence of intensity distribution on strength endurance training adaptations.

You can learn more about the optimal exercise order at the SuppVersity

What's the Right Training 4 You?

Hypertrophy Blueprints

Fat Loss Support Blueprint

Strength Training Blueprints

Study: Over-training Exists

Recovering from the Athlete's Triad

You may also remember that no previous study has addressed the influence of "intensity distribution", i.e. the way intensity and volume are distributed across the training sessions, on the effectiveness of concurrent training (CT | see Figure 1). The goal was to prevent interference of the two types of training:

Figure 1: Training design of the experimental groups during the 8-week training period. Continuous-line and dotted-line circles represent the different training session modalities for the PT and TT groups, respectively. PT: polarized training group; TT: Traditional-based training group; BW: brisk walking; RM: repetition maximum; RNG: running; IST: intermittent sprint training (Varela-Sanz. 2016).

"Another problem which must be solved is the comparison of external training loads. Thus, our independent variable and focus was training intensity distribution with an equivalent total external load [...] of both training programs. A training group performed a combination of strength and endurance training aligned with the current ACSM recommendations of intensity distribution, while another group performed the same amount of external workload but with a polarized intensity distribution. Both ex. groups were evaluated before and after an 8-week training period (weekly training frequency of 3 days), and compared to a control group. To examine the effectiveness of the [...] training regimes, [...] physical (jump capacity, upper- and lower-body strength, running performance, and body composition), physiological (heart rate variability), and perceptual variables (rate of perceived exertion, training impulse, and feeling scale) were examined as dependent variables" (Varela-Sanz. 2016)

Thirty-one healthy sport science students (30 men, 5 women; all moderately active, but training less than 2 days per week apart from their academic activities which included a variable amount of PA on a daily basis) volunteered and were, after a 2-week familiarization phase (training thrice a week for two weeks), evaluated for resting heart rate variability (HRV), countermovement jump, bench press, half squat, and maximum aerobic speed (MAS).

I don't get it. How exactly did this "polarized training" work? Yes, the protocol was different from the one you may remember from Seiler et al. (2006) who tried to quantify training intensity distribution in elite endurance athletes. More specifically, subjects trained thrice a week (i.e. Monday, Wednesday, and Friday) for ~120 min each on Monday and Friday, and ~60 min on Wednesday. The training sessions on Mondays and Fridays consisted of cardiorespiratory exercise training (i.e. brisk walking or running) followed by resistance exercise training; meanwhile on Wednesdays participants only performed cardiorespiratory exercise training.

Each training session started with a standardized warm-up that consisted of 5 min of calisthenics followed by 5 min of brisk walking at 30% of the MAS. Before resistance exercises, participants also performed a specific warm-up that consisted of 2 sets of 8 repetitions of the resistance circuit they performed during the familiarization period with a OMNI-Scale perception of effort of 2-3. Cooling down exercises consisted of 2-3 sets of 15 s of stretching exercises of the muscle groups involved during the session. The exercises during the actual workout were bench press and half squat. Based on the conclusions of Simão et al., whose study had revealed that you will see greater gains on those exercises you do first in your workout, the order of resistance exercises was alternated each week. In that, the TT group performed 3-5 sets of 10-12 RM with 3 min of rest between sets. The PT group performed 3-5 sets of 5 RM on Mondays, and 2-4 sets of 15 RM on Fridays. The rest between sets was always 3 min. Resistance exercise workloads were equated.

All were then randomly distributed into either a traditional-based training group (TT; n=11; 65-75% of MAS, combined with 10-12RM), polarized training group (PT; n=10; 35-40% and 120% of MAS, combined with 5RM and 15RM), or control group (CG; n=10).

Figure 2: Relative changes in heart rate, jump height, peak power, bench press (1RM) and half squat (1RM) after 8 weeks of traditional (TT), polarized (PT) training or control (Varela-Sanz. 2016).

After 8 weeks of training (3 days.week-1), TT and PT exhibited similar improvements in MAS, bench press and half squat performances. No differences were observed between TT and PT groups for perceived loads. There were no changes in heart rate variability (HRV) for any group although TT exhibited a reduction in resting HR.

Figure 3: Effect sizes corresponding to the relative values in Figure 1 (Varela-Sanz. 2016).

What is worth mentioning, though, is that, compared to other groups, the PT group maintained jump capacity with an increment in body weight and BMI without changes in body fatness, in other words: they gained muscle, but also fat (see Figure in Bottom Line | body fat measured by skinfold "only").

There's one thing we didn't discuss yet: Was the polarized training maybe less taxing or more fun? The findings of the study at hand suggest that this was the case: TT and PT reported similar perceptions of effort, sensations, and internal load levels over the 8-week training period. Briefly, RPE and TRIMPS increased progressively along the 8-week training period. These perceptual levels demonstrated an increase in external load during the 3rd microcycle compared to the 1st and 2nd microcycles of each mesocycle. Thus, "the current findings suggest that different concurrent training regimes of equated loads could be similarly perceived by participants" (Varela-Sanz. 2016).

Effects on body composition; effect sizes and rel. (%) changes (Varela-Sanz. 2016).

Bottom line: The previously outlined observations lead the scientists to conclude that their funky polarization approach to concurrent training "induced similar improvements in physical fitness of physically-active individuals", but that "PT produced a lower interference for jumping capacity despite an increment in body weight, whereas TT induced greater bradycardia" (Varela-Sanz. 2016).

The fact that there were further benefits in terms of peak power, squat and bench press performance, but that those were not statistically significant (see Figure 2), however, is something the scientists don't mention in the abstract, even though these differences could become significant in the longer (>8 weeks) term.

A mistake? No, in view of the conflicting evidence from the calculated effect sizes (see Figure 3), it is absolutely correct to say that there were no meaningful inter-group differences in the most important parameters for most trainees, i.e. the bench press, half squat and the effects on body comp (see Figure on the right) | Comment!

References:

• Seiler, K. Stephen, and Glenn Øvrevik Kjerland. "Quantifying training intensity distribution in elite endurance athletes: is there evidence for an “optimal” distribution?." Scandinavian journal of medicine & science in sports 16.1 (2006): 49-56.
• Simao, Roberto, et al. "Exercise order in resistance training." Sports Medicine 42.3 (2012): 251-265.
• Varela-Sanz, Adrián; Tuimil, José L.; Abreu, Laurinda; Boullosa, Daniel A. "Does concurrent training intensity distribution matter?" Journal of Strength & Conditioning Research: Post Acceptance: May 09, 2016 doi: 10.1519/JSC.0000000000001474.

Cardio Can BOOST Your Gains?! Do it Before Weights and be Rewarded With 28% Increased Fiber Size & VO2 Gains

Cardio Can BOOST Your Gains?! Do it Before Weights and be Rewarded With 28% Increased Fiber Size & VO2 Gains

aerobic exercise build muscle build strength cardio concomitant training resistance training VO2 vo2max

It may be important that the subjects cycled, because a recent review of the potential interference of cardio w/ strength training shows that cycling is the least likely to affect your gains (Murach. 2016).

In previous articles at the SuppVersity, I have written about the still ubiquitous concern that cardio training (or aerobic training, in general) could hamper your size and strength gains - a fear that is, unless you overdo it, unwarranted (learn more about HIIT & "regular" cardio training).

Now, a recent study from the Mid Sweden University shows that the opposite could be the case, i.e. that the hypertrophy response to exercise can actually be stimulated by combining resistance training not just with "cardio", but with "cardio" (=continuous cycling) and HIIT - at least if it's done not after, but before resistance training.

Are you looking for muscle builders for the year 2016? Find inspiration in these articles:

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

1, 2, or 5 sets per Exercise? What's "best"?

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!

The authors of the study, Zuzanna Kazior, Sarah J. Willis, Marcus Moberg, William Apró, José A. L. Calbet, Hans-Christer Holmberg, andn Eva Blomstrand were (just like you?) unhappy with the contradictory outcomes of existing studies on the effect of endurance exercise on the anabolic response to strength training. Accordingly, they designed a study to "re-investigated this issue, focusing on training effects on indicators of protein synthesis and degradation" (Kazior. 2016).

Figure 1: Overview of the resistance (top) and cardio training (bottom) protocols in the study at hand (Kazior. 2016).

In said study, two groups of previously not regularly trained male subjects performed 7 weeks of resistance exercise alone (R; n = 7) or in combination with preceding endurance exercise, including both continuous and interval cycling (ER; n = 9). You can see the exact protocols in Figure 1, with the resistance training part being on the top and the endurance / HIIT part on the bottom (the number of training sessions in the ER and R group were identical; importantly, the endurance training was performed before the resistance training and included an extra 5-min warm-up + cool-down before and after the E-part.

Did carbohydrates make the difference? Within 20 min after completion of a training session, subjects in the R-group received a protein supplement (Kolozzeum Pure Whey, Stockholm, Sweden), 20 g dissolved in 500 ml of water to enhance muscle recovery. The ER-group were given this same supplement, but with addition of maltodextrin (Fairing Fast Carbs, Järfälla, Sweden) in an amount corresponding to the individual´s calculated energy expenditure during the endurance training - did the maltodextrin make a difference? Based on the results of previous studies, this seems very unlikely. While carbs alone can enhance the protein synthetic response to resistance training (Børsheim. 2004), studies show no benefit of adding it to a sufficient amount of protein that is consumed right after resistance training workouts (Koopmann. 2007). 

Biopsies were taken from the lateral part of m. quadriceps, i.e., the vastus lateralis, both before and after 7 weeks of training. To ensure the results were not messed up, ...

"[t]he subjects were instructed to refrain from training for 2 days prior to the pre-training biopsies and the post-training biopsies were taken approximately 2 to 3 days after the final session in 15 subjects, but in one subject the post-training biopsy was taken 90 hours after the final session. During this period the subjects also refrained from training" (Kazior. 2016).

All data are expressed as means ± SD and were checked for normal distribution before performing parametric statistical analyses. A two-way repeated measures ANOVA (time, group) was applied to evaluate and compare the effect of training in the R and ER groups. When the ANOVA showed a significant main effect or interaction between time and group, Fisher’s LSD post hoc test was applied to identify where the differences occurred. A P-value <0.05 was considered to be statistically significant.

Figure 2: Levels of proteins in the Akt signaling pathway before and after 7 weeks of training. (A) Akt, (B) mTOR and (C) S6K1 in skeletal muscle before (Pre) and after (Post) 7 weeks of strength training only (R) or combined endurance and resistance exercise (ER). Representative immunoblots from two subjects. *P < 0.05 for Post vs. Pre (Kazior. 2016).

While similar increases in leg-press 1 repetition maximum (30%; P<0.05) were observed in both groups, irrespective of the maximal muscle gains - a discrepancy of which the scientists say that it "suggests that the improvement in maximal strength (1RM) observed following our relatively short 7-week period of training is due largely to neuromuscular adaptation" (Kazior. 2016), the scientists observed a striking and highly significant difference between the changes of the subject's maximal oxygen uptake (a marker of cardiovascular fitness) in the two groups. As you may already have expected, the latter was elevated (8%; P<0.05) only in the ER group, while the strength training only group saw no increase in this important fitness marker.

Figure 3: Pre- vs. post changes in fiber are and capillary density in both groups (Kazior. 2016).

And what about the gains? As far as those were concerned, Kazior et al. observed significantly larger increases in the ER training group as well. More specifically, the ER group saw gains in both, the areas of both type I and type II fibers. The R protocol, on the other hand, increased only the area of the type II fibers, which is why it is not exactly surprising that the mean fiber area increased by 28% (P<0.05) in the ER group, whereas no significant increase was observed in the R group - a difference that appears to be in line with the expression of the anabolic proteins Akt and mTOR, which were both enhanced in the ER group, whereas only the level of mTOR was elevated following R training. The scientists further analyses showed that...

"[the t]raining-induced alterations in the levels of both Akt and mTOR [both anabolic] protein were correlated to changes in type I fiber area (r = 0.55–0.61, P<0.05), as well as mean fiber area (r = 0.55–0.61, P<0.05), reflecting the important role played by these proteins in connection with muscle hypertrophy. Both training regimes reduced the level of MAFbx protein (P<0.05) and tended to elevate that of MuRF-1 [both catabolic]" (Kazior. 2016).

In view of these findings, it is only logical that the authors conclude that "the present findings indicate that the larger hypertrophy observed in the ER group is due more to pronounced stimulation of anabolic rather than inhibition of catabolic processes" (Kazio. 2016) - irrespective of the fact that they cannot tell for sure what it was that triggered these practically relevant differences.

Can the increase in IGF1, GH and testosterone as it was observed W/ Cardio first by Rosa et al. (2014) explain the increased size gains?

So what's going on, here? While you may expect that the addition of carbohydrates after the workout in the ER group could have something to do with the increased size gains, the data discussed in the red box shows that this is relatively unlikely (even though it could be the reason why AKT increased only in the ER group).

As far as the reasons for the surprising differences to other studies are concerned, we are thus left with two options: (1) the cardio protocol with steady state + HIIT could be special, or (2) doing cardio before not after strength training could be special. Interestingly enough, I've written about potential anabolic benefits of doing your cardio before weights, before: In a 2014 study, Rosa et al. observed significant increases in the purportedly muscle building hormones GH, IGF1 and testosterone when cardio was done before weights.

Whether it's in fact a pro-anabolic response to reversing the more common order of resistance training > cardio to cardio > resistance training does yet seem questionable - irrespective of the fact that the acute GH response was in fact one out of two parameters of which West et al. have found that it correlates with the actual muscle gains in their seminal 2012 study (discussed here) | Maybe you've got better explanations? If so, leave them in a comment on Facebook!

References:

• Børsheim, Elisabet, et al. "Effect of carbohydrate intake on net muscle protein synthesis during recovery from resistance exercise." Journal of Applied Physiology 96.2 (2004): 674-678.
• Kazior Z, Willis SJ, Moberg M, Apró W, Calbet JAL, Holmberg H-C, et al. "Endurance Exercise Enhances the Effect of Strength Training on Muscle Fiber Size and Protein Expression of Akt and mTOR." PLoS ONE 11.2 (2016) : e0149082. doi:10.1371/journal.pone.0149082
• Koopman, René, et al. "Coingestion of carbohydrate with protein does not further augment postexercise muscle protein synthesis." American Journal of Physiology-Endocrinology and Metabolism 293.3 (2007): E833-E842.
• Murach, Kevin A., and James R. Bagley. "Skeletal Muscle Hypertrophy with Concurrent Exercise Training: Contrary Evidence for an Interference Effect." Sports Medicine (2016): 1-11.
• Rosa C, Vilaça-Alves J, Fernandes HM, Saavedra FJ, Pinto RS, Machado Dos Reis V. "Order effects of combined strength and endurance training on testosterone, cortisol, growth hormone and IGFBP-3 in concurrent-trained men". J Strength Cond Res. (2014): Jul 15 Ahead of Print. 
• West, Daniel WD, and Stuart M. Phillips. "Associations of exercise-induced hormone profiles and gains in strength and hypertrophy in a large cohort after weight training." European journal of applied physiology 112.7 (2012): 2693-2702.

"HIIT-ing it After Arm Workouts Will Ruin Your Gains", Study Says and Confuses Statistical and Practical Significance

"HIIT-ing it After Arm Workouts Will Ruin Your Gains", Study Says and Confuses Statistical and Practical Significance

arms build muscle build strength cardio concurrent concurrent training exercise order HIIT strength training

Does this look as if sprinting would impair muscular development of arms or any other muscle? I mean, come on - look at the average sprinter: Many gymrats dream of the arms and overall muscular physique they have; no wonder that the data from the full-text shows a different picture than the abstract would suggest.

I have repeatedly written about combining strength and classic endurance training. With endurance first, endurance last and even endurance in-between the studies yielded often very different results in terms of what would be the optimal way to combine both. With a few exceptions in which resistance training was combined with crazy endurance training sessions, however, I've yet never written about nor seen compelling evidence for the often-heard claim that "cardio ruins your gains".

For HIIT, i.e. high-intensity interval training, a recent study from the Nippon Sport Science University does now claim, though, that my that combining HIIT and weight training may be a very bad idea, ... an idea that may in fact, just as the broscientific nightmare suggests "ruin your gains, bro!" Upon closer scrutiny, however, things appear less unambiguous than the abstract would have it...

You can learn more about the optimal exercise order at the SuppVersity

Before, After or In-Between?

Exercise Order and Leptin Levels

Cardio First for Anabolism?

Large Muscle Groups First?

Combine Cardio & Strength, Right

Cardio or Weights First? What the...

The purpose of the study was to examine whether or not lower limb sprint interval training following arm resistance training influences training response of arm muscle strength and hypertrophy. Or in short: Will doing HIIT sprints immediately after an arm workout ruin the strength and strength gains you've primed before? 

Figure 1: According to the study, you better don't do HIIT sprint training after an intense arm workout if you don't want to ruin the strength and size gains you "primed" with curls and co (photo from Kikuchi. 2015)

The subjects, twenty previously only lightly trained men, were divided into resistance a training group (RT, n=6) and concurrent training group (CT, n=6).

• The RT program was designed to induce muscular hypertrophy (3 sets x 10 repetitions (reps) at 80% 1 repetition maximum [1RM] of arm curl exercise), and was performed in an 8-week training schedule carried out 3 times per week on nonconsecutive days. 
• Subjects assigned to the CT group performed identical protocols as strength training (ST) and modified sprint interval training (4 sets of 30-s maximal effort, separated in 4m 30-s rest intervals) on the same day. 

The relevant study outcomes the researchers evaluated were the changes in maximal oxygen consumption (VO2max), muscle cross-sectional area (CSA), and 1RM that were measured before and after the 6-week study.

Figure 1: Relative changes in VO2max (conditioning), muscle size (CSA) and strength (1-RM) over 6 wks (Kikuchi. 2015).

As the data in Figure 1 reveals, significant increases in VO2max from pre- to post-test were observed only in the CT group (p=0.010, ES=1.84), but not in the RT group (p= 0.559, ES= 0.35). The rest of the results in Figure 1, however should be kind of surprising to anyone who has read the researchers conclusion that "our data indicate that concurrent lower limb sprint interval training interfere with arm muscle hypertrophy and strength" (Kikuchi. 2015).

No, you are not mistaken. The average muscle size and strength gain in the combined training group was larger. The reason the scientist still claim that their study would show that HIIT impedes strength adaptation is a statistical one. While the changes in the CT group had p-values p > 0.05 and were thus not statistically significant. The (albeit smaller) mean increase in the RT group was significant. Accordingly, the corresponding "effect size" in the RT group is larger than the one in the CT group and thus HIIT training must be bad, right? Well,... I don't think so.

If you take a closer look at the individual muscle  size and strength development, you should notice that being afraid that sprints would ruin your arm development is unwarranted and the statistical significance and effect sizes of the changes practically irrelevant.

Beware of bling faith in abstracts! If you look at my plot of the individual data the scientists luckily published with their full-text, it is yet obvious that this study does not prove and if we are honest, not even really suggest that there practically relevant negative effects of doing HIIT in this workout. If you just read the conclusion to the abstract, which reads "our data indicate that con-current lower limb sprint interval training interfere with arm muscle hypertrophy and strength" (Kiku-chi. 2015), you may be inclined to make unne-cessary changes to your workout that are neither necessary or productive. After all, the objective result of the study is that in some individuals it is possible that the addition of HIIT to an arm workout may have a minor impact on their gains.

In view of the facts that there's (a) one person with a roughly ~41% increase in sleeve sizes in each group and that (b) the average increase in sleeve size would be 23% in the CT and only 21% in the RT group if the two outlayers who lost muscle (one in each group) were excluded, though, I would suggest you ignore this possibility unless you realize that you're making no gains at all with concurrent training. This doesn't falsify the scientists' conclusion, which is based on scientific standard procedure, i.e. look for statistical significant results, use those to make your conclusion, but I felt I needed to write this article to put the theoretically correct interpretation of results of an unquestionably under-powered study into perspective | Comment!

References:

• Kikuchi et al. "The effect of high-intensity interval cycling sprints subsequent to arm-carl exercise on muscle strength and hypertrophy in untrained men: A pilot study." Journal of Strength and Conditioning Research Publish (2015): Ahead of Print | DOI: 10.1519/JSC.0000000000001315

Cardio After Weights! Doing Resistance Before Endurance Training Has More Beneficial Effects on Leptin, Cortisol, Testosterone and Body Composition in Young Men

Cardio After Weights! Doing Resistance Before Endurance Training Has More Beneficial Effects on Leptin, Cortisol, Testosterone and Body Composition in Young Men

build muscle cardio cortisol endurance endurance training exercise order leptin lose fat resistance training testosterone weight training weights

I can almost guarantee that the results of this study are not sex-specific. Ladies, pick up the weights fater you hit the treadmill, stairmaster, elliptical or other torture instrument you like to use!

It has been a while since the last study on exercise order (cardio or weights first) has been published. Now, scientists from the University of Kurdistan have conducted another study to investigate the effects of intrasession sequencing of concurrent resistance and endurance training on the serum leptin, testosterone, cortisol responses and body composition in obese men.

And don't worry, we are not talking about useless acute-phase data that shows no correlation with either strength or muscle gains, or fat loss (West. 2012). Sheikholeslami-Vatani and colleagues conducted an eight-week study on thirty obese young male students without continuous exercise history (age: 23.2±1.4 year, BMI: 31.8±1.6 kg/m²).

You can learn more about the optimal exercise order at the SuppVersity

Before, After or In-Between?

Exercise Order and Leptin Levels

Cardio First for Anabolism?

Large Muscle Groups First?

Combine Cardio & Strength, Right

Exercise Order Reloaded

The subjects were randomly divided into three groups: concurrent resistance-endurance (CRE, n = 10) group, concurrent endurance-resistance (CER, n = 10) group and control (C, n = 10) group (no training program). The concurrent training groups (CER and CRE) trained three times a week on alternate days for 8 weeks. The training itself consisted of which consisted of ...

"running with 70—75% of maximal heart rate (HRmax) for 10 minutes which gradually increased to 80% HRmax for 21.5 minutes [plus] resistance training consisted of 3 sets of 8 repetitions at 80% of 1 repetition maximum (1RM) in 5 resistance exercises (leg extensions, lying leg curl, triceps pushdown, bench press and lateral pull down)" (Sheikholeslami-Vatani. 2015). 

In-between the endurance and resistance (or vice versa) training parts of the workouts, the subjects rested for 5 minutes. Blood sampling and skin-fold measurements to asses the body composition was conducted 48 hours before the start of the course and again 48 hours after the last training session (learn why waiting longer for the body comp test may have been better, but no study does that).

Figure 1: Relative changes in hormone levels (left) and absolute and relative changes in body fat fat free mass and body fat % (right) after 8 weeks of doing nothing (C) or doing cardio (CER) or weights (CRE) first (Sheikholeslami-Vatani. 2015).

I've plotted the most important results in Figure 1a & b. So, let's take a look: The first thing that everyone should see is that both workout regimen had relevant health and physique effects:

• 

  Similar gains w/ weights vs. cardio first in trained men | more.

  normalization of leptin levels (health)
• slight increases in testosterone (health)
• increases in cortisol (which are benign | learn why)
• significant reductions in body fat (health + physique)
• increases in fat free mass (health and physique)

In that, the resistance training first (CER) group came off slightly better in all tested study outcomes. Statistical significant inter-group differences, however, were observed only in comparison to the control group. In view of the fact that the body fat (total and %) improvement reached statistical significance compared to control only in the endurance first, group, yet not in the strength first group, one may still argue that the difference between cardio first (CER) and weights first (CRE) was "almost significant" ;-)

Weights or Cardio? What's the Best Visceral Fat Burner + How Often, Long and Intense Do You Have to Train | Learn more!

So, weights first is the way to go? Well, I assume I should write that doing both on separate days and thus doing having 5-6 workout days per week may have even more pronounced effects on the body composition of obese young men. In the end, though, I have no evidence to prove that doing the same amount of cardio on a separate day would actually have yielded greater improvements in body composition. Against that background and in view of the fact that three workouts per week is everything that fits into the busy schedules of the average trainee, we are left with the confirmation that (a) doing (intense) cardio and weights in one session feasible and effective when the goal are health and physique improvements and that (b) if you or your clients combine both, you better start with the weights, not the cardio part | Comment!

References:

• Sheikholeslami-Vatani, D., et al. "The effect of concurrent training order on hormonal responses and body composition in obese men." Science & Sports (2015).
• West, Daniel WD, and Stuart M. Phillips. "Associations of exercise-induced hormone profiles and gains in strength and hypertrophy in a large cohort after weight training." European journal of applied physiology 112.7 (2012): 2693-2702.

Load Carrying Cardio Doesn't Affect Muscle Protein Flux While Intra-Workout EAA Reduces Protein Breakdown and Bumps Nitrogen Balance From Zero to Plus 50µmol/kg/h

Load Carrying Cardio Doesn't Affect Muscle Protein Flux While Intra-Workout EAA Reduces Protein Breakdown and Bumps Nitrogen Balance From Zero to Plus 50µmol/kg/h

amino acid supplementation anti-catabolic cardio catabolism EAA endurance exercise endurance training essential amino acids intra-workout load carrying cardio protein breakdown

While this picture shows loaded cardio in its most beautiful form, the study investigated loaded cardio on the treadmill and compared it (for questionable reasons) to non-loaded cardio on a stationary bike and guess what: Both burn the same amount of muscle - NET: Zero!

Carrying a (heavy) load during cardio? Sounds dumb? Well, that's however, how the real world looks like. Not just soldiers who are carrying armor and a heavy backpack in the field, but also hikers will attest to the fact that doing "cardio" with a weight on your shoulders or elsewhere is more natural than running around in the park with your mobile and ear-plugs as the only load you're carrying on top of your ultra-light runners clothing.

With that being said, it is actually quite astonishing that Stefan M. Pasiakos and colleagues from the Military Nutrition Division at the US Army Research Institute of Environmental Medicine in Natick are the first to take a look at the muscle anabolic and catabolic effects of regular (unloaded) and loaded cardio training in 40 free-living healthy, physically fit (peak oxygen uptake, VO2peak 40/60 mL/ kg/ min), adults (37 males and 3 females), normal weight men and women between the ages of 18–39 years.

HIIT is the ideal complement to classic "cardio" training!

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

In said study, the volunteers were then randomly assigned to one of four experimental groups, each
of whom performed a single 90 min exercise bout.

• Two groups performed CE and the other two performed LC. 
• One of each of the exercise groups received EAA drinks to consume during exercise, and the other groups received control (CON) drinks. 

To determine the effects on skeletal muscle, the subjects' individual muscle protein synthesism (MPS) was assessed during exercise and recovery and whole protein turnover was determined in recovery only. What may be a bit surprising in this context is the fact that a resting MPS measure was not included in the study. The authors, however, have a good argument to neglect this, when they say that (a) the MPS responses to endurance-type exercise (i.e.,as they relate to resting MPS) are well established and that (b) their ...

"[...] intent was not to determine temporal changes in MPS within an exercise mode (with or without EAA), but to examine MPS responses between LC and CE during exercise and recovery independently" (Pasiakos. 2015).

Another thing that was just like in any other study, though, was the standardization of diet and physical activity, the scientists describe as follows:

"Volunteers completed 3 d diet and activity records at baseline, and similar to our previous work (Pasiakos. 2011), these records were used to individually prescribe 7 d lead-in diets to maintain body weight and to limit the potential confounding effect of diet on outcome measures. Compliance was confirmed by 24 h dietary recalls conducted every two days during the lead-in phase (Food Processor SQL1, version 10, ESHA Research, Salem, OR) (Table 1). Volunteers were also instructed to maintain activity levels reported at baseline for the first five days of the lead-in phase. All resistive and endurance-type activity was prohibited 48 h before data collection to minimize any potential residual effects of previous exercise on protein turnover" (Pasiakos. 2015).

The actual news is however not the dietary standardization what you are (rightly) interested in is probably the exercise protocol which is - and I will get to that in the bottom line - not ideal: While the LC, i.e. the load carriage training, was performed by walking on a treadmill while wearing a weighted vest equivalent to 30% of baseline body mass, the CE, i.e. the control endurance exercise, was non-weight bearing and performed on a cycle ergometer (Lode, BV, Netherlands), of which the scientists say that they used it to "allow for comparisons with our previous studies" (Pasiakos. 2015).

Illustration 1: Graphical overview of the study design (Pasiakos. 2015) | EAA = 10g of EAAs, CON = non-nutritious control drink; LC = load carrying cardio on a treadmill, CE = control endurance exercise on a stationary bike.

What's unquestionable a strength of the study, though, was the fact that the baseline VO2peak and associated heart rates at maximal and submaximal levels were used to establish target exercise intensities for the LC and CE trials. In addition, speed and grade for LC and power (watts) for CE were adjusted to match the absolute exercise intensity (intended oxygen uptake was 2.4 L /m) and
to elicit a similar energy cost (intended energy expenditure was 1050 kcal /90 min) between
LC and CE. Lastly, ...

"[m]atching the intensity and energy cost was done to isolate the effects of the possible differences in mechanical force and contractile properties of LC and CE from the relative intensity and energy cost of the exercise bout [and a] familiarization trial was conducted to ensure the accuracy of the exercise prescription and the ability of the volunteer to complete the prescribed exercise bout" (Pasiakos. 2015).

As previously alluded to, the intra-workout beverage the subjects consumed was either a high EAA drink (10 g EAA: 0.7 g histidine, 0.7 g isoleucine, 3.6 g leucine, 1.2 g lysine, 0.3 g methionine, 1.4 g phenylalanine, 1.0 g threonine, and 1 g valine) or an identically looking placebo drink (non-nutritive).

Figure 1: Overview of protein fluxes (synthesis vs. breakdown and oxidation) and subsequent net protein balance in the four treatment groups, i.e. loaded and control cardio with and with out EAA (Pasiakos. 2015)

Interestingly enough, the latter, i.e. the 10 grams of EAA drink that was consumed in four small doses (i.e., 350 mg of phenylalanine and 900 mg of leucine per serving), over 90 min to minimize "any isotopic dilution that may have occurred if the EAA drink was consumed as a bolus" (Pasiakos. 2015) was the only treatment that made a difference to the protein flux parameters illustrated in Figure 1. In that it is worth mentioning the tthe difference in protein oxidation alone does not fully explain the conservation of skeletal muscle protein even if we assume that all the amino acids that were oxidized during the EAA supplementation trial came from the EAA supplement. This is curious in view of the lack of effect of BCAAs on exercise (learn more) induced protein breakdown and points with a finger to other EAAs as potential motors of this effect.

Figure 1: Protein synthesis. Mixed-muscle (A), myofibrillar (B), and sarcoplasmic (C) muscle protein synthesis (MPS) during exercise and mixed-muscle (D), myofibrillar (E), and sarcoplasmic (F) MPS in recovery from a 90 min, metabolically matched load carriage (LC) or conventional endurance (CE) exercise bout, with and without (control, CON) essential amino acid (EAA) supplementation. Data are mean ± SD, n = 10 per group. †Mode main effect; LC different than CE, P < 0.05. *Drink main effect; EAA different than CON, P < 0.05 (Pasiakos. 2015).

The fact that the loading didn't make a difference in either direction, i.e. that it did neither increase nor decrease the breakdown or synthesis of muscle protein may be surprising, but it's not the only result worth mentioning before we evaluate the results in the bottom line. In addition, it should be noted:

1. The EAA-mediated decrease in muscle breakdown was complemented by both enhanced mixed-muscle and sarcoplasmic MPS during exercise.
2. During the recovery phase, the mixed muscle and sarcoplasmic protein synthesis in response to loaded cardio training were higher than they were in the control group.

Of these results, finding #2 is of most interest as it puts the alleged uselessness of loaded cardio into perspectives. Muscles do after all grow during rest and if the muscle protein synthesis during the recovery phase is increased compared to the control non-loaded exercise this clearly suggests that loaded endurance exercise is more anabolic than non-loaded endurance exercise.

Yes! You can use whey or even regular milk protein, as well and benefit. Better don't eat a steak during your workout though. Learn more in this SV Classic  "23g of Dairy Protein + 5g of Leucine Turn Cardio Sessions Into Muscle Building Workouts"

So, loaded endurance exercise is not much, but a little better? Well, in this study it appears to be as if the former was the correct conclusion to be drawn. Generalizations, however, must be made with utmost care. Especially in view of the unfair comparison of walking on a treadmill with cycling on a bike, of which you could argue that it is naturally less anabolic than walking - irrespective of whether you're carrying an extra-load or not. Thus, the researchers have weakened the generalizability of their results by making the (imho unnecessary) decision to rely on a tried and proven method, i.e. cycling, only to (as I suspect) make it easier to standardize the workload in numbers. This, however, is bogus: I mean, you all have probably worked out for say 500kcal on an exercise bike and for 500kcal on a treadmill. Now tell me: What did you feel was more exhausting and had a subjectively significantly larger impact on your metabolism? You answer probably is 'treadmill'.

Eventually, the most practically relevant information you can draw from the study at hand are thus: (A) You can do both 90 minutes of loaded cardio on the treadmill and 90 minutes of classic cardio on an exercise bike without any muscle loss (at least from the exercised muscles) even if you consume only water (see net balance = 0 in Figure 2). (B) If you bring 10g of EAA and consume them over the course of your workout you may even hop off the treadmill or bike with a few micrograms extra muscle on your legs. And (C) if you chose the treadmill and loaded cardio this will trigger a better post-workout anabolic response than the bike. How meaningful all that is - in terms of gains, I mean - will yet have to be seen in future long(er)-term studies | Comment!

References:

• Pasiakos, Stefan M., et al. "Leucine-enriched essential amino acid supplementation during moderate steady state exercise enhances postexercise muscle protein synthesis." The American journal of clinical nutrition 94.3 (2011): 809-818.
• Pasiakos SM, McClung HL, Margolis LM, Murphy NE, Lin GG, Hydren JR, et al. "Human Muscle Protein Synthetic Responses during Weight-Bearing and Non-Weight-Bearing Exercise: A Comparative Study of Exercise Modes and Recovery Nutrition." PLoS ONE 10.10 (2015): Online only.