Serum & Intramuscular Testosterone, DHT and Androgen Receptor Response to High vs. Low Volume Training

Another set for another ng of testosterone? Does it work that way and is it worth it - not just on paper, but in terms of real gains?

I know that we don't know! And among the many things we don't know the influence of the post-workout elevation in the long-thought "anabolic" hormones testosterone, growth hormone, and co. is unquestionably one of my personal favorites. You've read about it, here at the SuppVersity many times and I got to tell you in advance that the absence of convincing evidence for / against its importance will become a problem in the bottom line of today's SuppVersity article dealing with the intriguing results of an experiment that has been conducted by Lukas J. Farbiak as part of his Honors Thesis (Farbiak. 2013).

"Effects of Lower- and Higher-Volume Resistance Exercise on Serum Total and Free Testosterone, Skeletal Muscle Testosterone and Dihydrotestosterone Content, and Skeletal Muscle Androgen Receptor mRNA Expression and Protein Content"

That's quite a title for a thesis right? Well, one thing's for sure: Having the words, "high, "low", "training volume", "resistance exercise", "total and free testosterone", "dihydrotestostereone", etc. all in the headline is certainly an advantage when it comes to findability of a paper - or in this case - a thesis in a database. And in fact, it was really the title of the 91 page piece that has caught my eye, a couple of days ago - what peaked my interest, though were the research hypotheses Farbiak, whose thesis was by the way overseen by Darryn Willoughby, formulated:

• H1 : Following the HV [high volume] exercise bout involving both upper- and lower-body resistance exercise, a significant increase in serum testosterone will occur compared to the LV [low volume] exercise bout only involving lower-body resistance exercise. 
• H2 : Following the HV exercise bout involving both upper- and lower-body resistance exercise, a significant increase in muscle testosterone and DHT content will occur compared to the LV exercise bout only involving lower-body resistance exercise. 
• H3 : Following the HV exercise bout involving both upper- and lower-body resistance exercise, a significant increase in AR mRNA expression and protein content will occur compared to the LV exercise bout only involving lower-body resistance exercise.

I took the liberty of highlighting three things in Farbiak's hypotheses, which tell you why you want to know the outcome of the study, even if the current "state of the research" questions the significance of exercise-induced elevations of androgens in terms of their ability to elicit muscle growth.

What's special, here, is that we are not measuring serum levels exclusively, but get a much more detailed picture of the endocrine response to high vs. medium volume training.

Why would the internal androgen levels differ from those outside of the cell? The notion that this could and in fact is the case did not arise before Hammes et al. discovered that contrary to the previously heralded position that says that only free testosterone levels would matter and that the latter would be able to enter the cells via passive diffusion, the entrance of testosterone into the cell is actually governed by (attention please) megalin, a low density lipoprotein receptor (LDR) related  protein. According to Hammes, SHBG can bind to megalin can internalize the SHBG + androgen pair into the cytoplasm, where the binding globulin is degraded and the steroid will be released to the cellular environment.It goes without saying that this changes the interpretation of previous data and provides a whole new perspective on the androgen - muscle interaction with the formerly "passive" bound testosterone suddenly having the ability to promote hypertrophy.

In this context the relation of free androgens, androgen receptor expression and the presence and concentration of intra-muscular may well provide first insights into why previous studies, which have predominantly relied on the determination of serum levels without even checking,

• whether there were enough receptors to (this is an oversimplification) transduct the anabolic signal of workout induced increases in testosterone to the muscle cells, and
• to which extent the changes in extra-cellular androgen levels correlate with the amount of testosterone and DHT that's actually in the muscle.

Now that I have your full attention let's take a look at what kind of workout program we are dealing with in the study at hand, for which the researchers recruited 10 "apparently healthy resistance trained  [regular,  consistent  resistance  training (i.e. thrice weekly) for  at least 1 year prior to the onset of the study], men between the ages of 18-30" (Farbiak. 2013).

"In a randomized, cross-over design, participants visited the laboratory on 5 separate occasions in the following manner: visit 1 = entry/familiarization session, visit 2 = testing/resistance exercise session 1, visit 3 = 24 hour follow-up for session 1, visit 4 = testing/resistance exercise session 2, visit 5 = 24 hour follow-up for session 2. Relative to the testing sessions (visits 2 & 4), participants performed a resistance exercise session involving the knee extension exercise on two occasions separated by one week. One session constituted the control session and was preceded by rest and the other was preceded by the experimental session and preceded by a bout of high-volume, moderate-intensity upper-body resistance exercise using short rest periods." (Farbiak. 2013).

The dependent variables, i.e. serum free and total testosterone, intra-muscular testosterone, DHT and  AR  receptor mRNA, as well as protein expression were determined on all, but the initial entry/familiarization visit.

The workout itself (remember this is not a chronic resistance training study, as the one by West et al. (2012) which is - at least to my knowledge unique wrt to the real-world relevance of the data; learn more) consisted of

• LV - low volume: 5 sets of 5-RM (90%-95% 1-RM) of the bilateral knee extension exercise with 3 minutes of rest between sets.
• HV - high volume: Upper-body resistance exercise protocol of 4 sets of 10-RM each of the bench press, seated row, and overhead shoulder press exercises immediately prior to the knee extension protocol. 
• the initial load was set at 80% of the 1-RM for each participant. 
• if muscle fatigue/failure occurred during a set, a spotter provided assistance until the participant completed the remaining repetitions and resistance was reduced for subsequent sets

In all cases, 2 minutes of rest separated sets and exercises. All training sessions were conducted in
the Baylor Laboratories for Exercise Science & Technology (BLEST) and supervised by study personnel.

Figure 1: Sum total and free testosterone in response to high and low volume training (Farbiak. 2013)

Now, the data in figure 1 actually mirrors what we already know: The overall serum response to high volume training is more pronounced that that to playing around on a leg extension machine (which happens to be the favorite benchmark for the / I repeat myself / likewise not very useful studies on PWO protein synthesis).

"Several studies have shown that acute resistance exercise bouts elicit a testosterone response (Kraemer. 1990; Kraemer, Gordon et al., 1991; Kraemer, Hakkinen et al., 1999; Spiering, Kraemer. 2008; Roberts. 2009). Such exercise bouts shown to elicit a testosterone response need to consist of a high intensity (load) (85%-95%) of one repetition max and meet a minimum threshold, and moderate to high volume (set x number of reps x intensity). Exercises that utilize large muscle groups (i.e. power clean, squats, and dead lifts) as well as performing exercises involving large muscle groups first, with short rest periods (30-60 sec) have shown to elicit the greatest response (Kraemer, Marchitelli et al., 1990; Spiering, Kraemer et al., 2008; Vingren, Kraemer et al., 2010). [...] It is known that the testosterone response resistance exercise is highly variable (Kraemer, 1988). Thus, it is possible that after multiple years of resistance training, the initial phasic response of the hypothalamus gonadal axis (aka. testosterone axis) response elicited by resistance exercise bout un trained individuals has become blunted from habitual resistance exercise. However, it is necessary that further research be conducted to elucidate why this blunted response occurs." (Farbiak. 2013; my emphasis of the key points)

As far as the differential response of free and total testosterone is concerned the tendency for both to go hand in hand has been observed in previous studies, as well (Durand. 2003; Kraemer. 1990; Kraemer. 1991; Kraemer. 1999; Spiering. 2008; Roberts. 2009). What's "new" or let's say something we have much less reliable data on are the changes that take place within the muscle (see figure 2)

Figure 2: Intra-muscular androgen & -receptor mRNA & protein expression (Farbiak. 2013)

Interestingly, enough those potentially far more relevant changes take place on a very different time-scale. While we do see the touted increases in serum testosterone in the immediate vicinity of the workout, the corresponding intra-muscular levels are actually declining from pre to post (red vs. blue bars). As Farbiak points out, these changes were yet statistically non-significant and to thus correspond to previous results presented by Vingren & Kraemer et  al. in 2008 (Kraemer. 2008). The same goes for the DHT response that did not make it past the p > 0.05 mark of statistical significance (FYI: this means the chance that this is just a statistical artifice is >5% and thus "not significant").

As far as the androgen receptor mRNA expression is concerned a often-cited (also by me, here at the SuppVersity) by Kraemer et al. observed a reduction in response to a single bout of resistance exercise, (Kraemer. 2010). The latter does actually conflict with in-vitro studies that suggested that the presence of higher testosterone levels would lead to an increased expression of androgen receptor mRNA and proteins - an observation of which Farbiak points out that it does not only stand in line with a previous study by Willoughby  and  Taylor (Willoughby. 2004) who observed a

"+35% and +43% increases in AR mRNA expression 48 hours after the first and third resistance exercise bouts, with a peak increase of 68% in AR mRNA expression occurring 48 hours after the second resistance exercise bout within the resistance exercise group" (Farbriak. 2013)

which was ascribed to corresponding increases in serum testosterone levels. In view of the fact that the latter were absent in Farbiak's subjects, it is not surprising that the existing increases in AR receptor mRNA in the study at hand did not reach statistical significance. Similarly, Farbiak was not able to show significant alterations in androgen receptor protein content in response to either LV or HV bouts of resistance exercise, which leaves us with pretty much of a null result and raises the question...

What do we make of this null result?

I guess the first thing would be to take a look at the underlying "mathematical" reason for the non-significance of the results... standard deviations - HUGE standard deviations, indeed. So huge that I initially thought that this must be a mistake, I mean if you have a mean pre-testosterone level of 43.59 ng/dl and a standard devition of 43.03 ng/dl, i.e. 99%, what can you expect? Now this is an extreme example, but in view of the relative small number of participants it should suffice to tell you that - maybe - we should not focus that much on statistical significance, here?

Suggested read: "Advanced Trainees Benefit from Increased Training Volume! Greater & Steadier Strength Gains with 8 Sets of Squats. Plus: Over 6 Weeks, 1 Set and 4 Sets Equally (In-)Effective." If higher volume begets higher T-responses and the latter is blunted in advanced trainees, it would appear logical that they benefit from doing more (learn more)

Schoenfeld mentioned similar effects in a whole host of pertintent studies in his excellent review of the literature on the effects of the exercise induced hormonal changes on muscle hypertrophy (I mentioned this review before, e.g. March 2, 2013; March 4, 2013). So it could simply be inter-individual variability that skewed the results. If that was the case, it is however unlikely to assume a dose-response relationship between any (serum or intramuscular) changes in androgens / androgen receptor expression and skeletal muscle hypertrophy - I mean that would imply much more pronounced differences in muscle growth in response to a workout than the real world results do indicate.

Another factor that may have influenced the results is the high training experience (>8 years) of the participants in the Farbiak study, if the initially cited hypothesis that the androgen response to exercise declines in experienced athletes turns out to be true, the non-significance of the endo- and paracrine hormonal response in the study at hand could well be "normal" and no anomaly. And if that was the case, it would suggest that the changes that were observed in previous studies, many of which were conducted on rookies, do matter - at least to a certain degree.

To use this as the only explanation for the (comparatively) exorbitant gains training noobs experience once they pick up their first dumb- and barbells would yet be shortsighted. To add it as yet one of the many confounding factors, on the other hand, would make perfect sense, as it would stand in line with the (comparably) short-term detrimental effects chronic resistance training without off-times has on the protein synthetic mTOR response to exercise (learn more about exercise induced "mTOR resistance").

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Bottom line: To sum it up, while we do now have another puzzle piece, it looks as if it only made us realize that our 1,000 piece puzzle is in fact a 10,000 piece puzzle and that it will probably require more than just a handful of follow up study to investigate the numerous factors "such as age, time of day [not all trainees trained at the same time, so the circadian rhythm may be an issue, in the study at hand], and training experience" (Farbiak. 2013) of which Farbiak speculates in the discussion of his honors thesis that they may account for the observed discrepancies and inconsistencies in testosterone response to acute resistance exercise... ah, and once we've done that, we would need more studies like the one by West et al. (2012) to see the real world implications. I guess, we better issue a bond to get those finance, right?

References:

• Farbiak, LJ. Effects of Lower- and Higher-Volume Resistance Exercise on Serum Total and Free Testosterone, Skeletal Muscle Testosterone and Dihydrotestosterone Content, and Skeletal Muscle Androgen Receptor mRNA Expression and Protein Content. A Thesis Submitted to the Faculty of Baylor University In Partial Fulfillment of the Requirements for the Honors Program. May 2013.
• Durand RJ, Castracane VD, Hollander DB, Tryniecki JL, Bamman MM, O'Neal S, Hebert EP, Kraemer RR. Hormonal responses from concentric and eccentric muscle contractions. Med Sci Sports Exerc. 2003 Jun;35(6):937-43.
• Hammes A, Andreassen TK, Spoelgen R, Raila J, Hubner N, Schulz H, Metzger J, Schweigert FJ, Luppa PB, Nykjaer A, Willnow TE. Role of endocytosis in cellular uptake of sex steroids. Cell. 2005 Sep 9;122(5):751-62. 
• Kraemer WJ, Marchitelli L, Gordon SE, Harman E, Dziados JE, Mello R, Frykman P, McCurry D, Fleck SJ. Hormonal and growth factor responses to heavy resistance exercise protocols. J Appl Physiol. 1990 Oct;69(4):1442-50.
• Kraemer WJ, Gordon SE, Fleck SJ, Marchitelli LJ, Mello R, Dziados JE, Friedl K, Harman E, Maresh C, Fry AC. Endogenous anabolic hormonal and growth factor responses to heavy resistance exercise in males and females. Int J Sports Med. 1991 Apr;12(2):228-35.
• Kraemer WJ, Häkkinen K, Newton RU, Nindl BC, Volek JS, McCormick M, Gotshalk LA, Gordon SE, Fleck SJ, Campbell WW, Putukian M, Evans WJ. Effects of heavy-resistance training on hormonal response patterns in younger vs. older men. J Appl Physiol. 1999 Sep;87(3):982-92.
• Kraemer WJ, Ratamess NA. Hormonal responses and adaptations to resistance exercise and training. Sports Med. 2005;35(4):339-61.
• Roberts MD, Dalbo VJ, Hassell SE, Kerksick CM. The expression of androgen-regulated genes before and after a resistance exercise bout in younger and older men. J Strength Cond Res. 2009 Jul;23(4):1060-7. 
• Schoenfeld BJ. Postexercise hypertrophic adaptations: a reexamination of the hormone hypothesis and its applicability to resistance training program design. J Strength Cond Res. 2013 Jun;27(6):1720-30.
• Spiering BA, Kraemer WJ, Anderson JM, Armstrong LE, Nindl BC, Volek JS, Maresh CM. Resistance exercise biology: manipulation of resistance exercise programme variables determines the responses of cellular and molecular signalling pathways. Sports Med. 2008;38(7):527-40.
• Spiering BA, Kraemer WJ, Vingren JL, Ratamess NA, Anderson JM, Armstrong LE, Nindl BC, Volek JS, Häkkinen K, Maresh CM. Elevated endogenous testosterone concentrations potentiate muscle androgen receptor responses to resistance exercise. J Steroid Biochem Mol Biol. 2009 Apr;114(3-5):195-9.
• West DW, Phillips SM. Associations of exercise-induced hormone profiles and gains in strength and hypertrophy in a large cohort after weight training. Eur J Appl Physiol. 2012 Jul;112(7):2693-702.
• Willoughby DS, Taylor L. Effects of sequential bouts of resistance exercise on androgen receptor expression. Med Sci Sports Exerc. 2004 Sep;36(9):1499-506.

"Just One More Set" (2/2): Three Sets of Three Exercises Three Times Per Week - High Volume Can Work. With Appropriate Rest Also to Build Strength & Power

High , not insane (!) volume training can be productive.

I hope that you have already being waiting for this post, so I'll try to cut myself short and get right to the facts. In yesterday's first part of "Just One More Rep" it turned out that a higher training volume sucks, when it comes to what is often thought would be its prerogative, i.e. using strength training to induce excess post-exercise oxygen consumption (EPOC) and lean out.

In view of these results you could argue that it would be totally logical that a higher training volume cannot be ideal for muscle gains either. After all those require energy and if the RMR does not go up, this would suggest that there was little to repair and supercompensate. A recent study (Naclerio. 2012) does yet refute this already intrinsically non-stringent considerations.

High volume can work! As long as it's high, and not simply insane.

The study was conducted by researchers from the University of Greenwich, the College of New Jersey, the European University of Madrid and the Appalachian State University and it has one caveat I don't want to hold back to the discussion of the results at the end of this post (although it will reappear and be addressed there): Though we are dealing with college athletes (20 male soccer and 12 female volleyball college players)  none of them had previous strength training experience. This may not be exactly representative of a dumb- & barbell god like you are *rofl*, but is at least better than taking totally untrained participants, where you never know if the the higher volume was too demanding for their musculature or their overall conditioning.

Moreover, the separate analysis of upper and lower body strength gains could shed some more light on whether or not legs do in fact need some more hammering to adapt than the smaller musculature of the upper body (cf. "Three is more than one").

Who and at which intensity for how many sets and reps?

The 32 athletes (age = 23.1± 1.57 yrs, injury free) with at least 3 years of experience as regular team sports practitioner were randomly assigned to one of four groups (all performed 8 reps at 75% of their 1-RM max per set!):

• low volume(LV), 1 set per exercise and 3 sets per muscle group per session;
• moderate volume (MV), 2 sets per exercise and 6 sets per muscle group per session;   
• high volume (HV), 3 sets per exercise and 9 sets per muscle group; 

and of course, the obligatory non-exercise control group (this leaves us with only 8 subjects per group, so don't expect all too meaningful p-values). Before and after the 6 week each subject underwent a progressive resistance test aimed to determine the 1RM and the maximal average power produced from light to heavy weights on two upper body exercises (bench press (BP) and upright row (UR)) and one lower body exercise (parallel squat (SQ)). The individual tests, were structured as follows:

"After a standardized warm up, each subject started the PRT  which consisted of 8 sets of 2 repetitions performed with maximal acceleration, alternating with rest periods between 2 min for the light load, 3 to 4 min for the moderate load and 5 minutes for the higher load. The 1st and 2nd sets were performed with a light weight (~25 to 45% of estimated 1RM), the 3rd and 4th sets with a medium weight (~50% to 65% of estimated 1RM), the 5th and 6th sets with a medium to heavy weight (~ 70% to 80% of estimated 1RM), and the 7th and 8th sets with a maximum or near maximum weight (~85% to 100% of estimated 1RM)." (Naclerio. 2012)

For the subsequent analysis the scientists picked those sets and reps, on which the subjects had lifted with the greatest average power (no sure whether this was the best idea, but alas).

The workouts - chest, shoulders, biceps + legs, back, triceps

It stands to reason that the exercises that were part of the testing procedure, i.e. bench presses (BP) and upright rows (UR), which were performed using Olympic bars and plates, as well as the classic back squat (till thighs were parallel to the floor, SQ), which was performed on a Smith machine, "in order to standardize exercise", were also the core exercises of the  actual workouts, the participants performed during the 6-week training phase.

Day 1 (chest, shoulders, biceps)	Day 2 (legs, back, triceps)
Bench press Incline Bench press Dumbbell Fly Upright Row Lateral Raise Posterior Lateral Raise Barbell Biceps Curl Dumbbell Biceps Curl Machine Biceps Curl	Smith Machine Parallel Squat Leg Press Knee Extension Lat Pull down Seated Row 1 Arm Dumbbell Row Machine Triceps Extension Standing Triceps Pushdown 1 Arm Triceps Extension
Table 1: Workout schedule, for set and rep scheme see text above .

Overall each subject took part in 18 training session, i.e. 3 per week. The training sessions were scheduled on non-consecutive days in a day 1 v.s day 2 fashion, with day 1 being 'chest + shoulder + biceps day ' and day 2 being 'legs + back  + triceps day'. Given the aforementioned volume prescriptions you see that the actual routines were actually more or less representative of what you will see the relatively sane part of the trainees actually do at the gym.

Figure 1: Relative change (in % of baseline) in 1RM and maximal average power during the 6-week intervention period (Naclerio. 2012)

If you take into account that these were the first real lifting sessions for most of the study participants, the same can be said of the strength gains I plotted relative to the respective baseline levels in figure 1. In fact, the multivariate analysis the scientists conducted showed that all training protocols yielded statistically significant increases in strength.

When gains are the goal: Volume (or stimulus?) does count!

In contrast to the EPOC values, of which we have learned yesterday that they do by no means benefit from increases in total workout volume, Naclerio et al. did actually observe a clear trend toward greater improvement in strength and power with the high vs. the low and even the medium volume protocol (at a similar overall volume, though with different exercises in a classic split routine). Thte most evident downsides to the lower volume programs, were

• no significant increases in the 1-RM squat in both the low and medium volume group, and
• no significant increases in the average power during the bench press,

where both, the medium (MV) and high volume (HV) protocols achieved significant before vs. after differences of 10% and 16%, respectively.

If you look at the overall pattern in figure 1 once more, there is still no clearcut picture emerging. While it does in fact appear as if the high volume routine appears to be in front in the majority of 1-to-1 comparisons, this is mainly based on an analysis of the improvements in maximum strength. With respect to the average power measurements, on the other hand, the authors are (partly) right to point out that you could argue in favor of both the low and medium volume protocols as being "better strategies for enhancing lower body or upper body average power performance." (Naclerio. 2012)

So is high volume the way to go - or no?

For the subjects who participated in this study (and maybe some of you), the last mentioned equivalence, if not superiority of the low(er) volume routines (1-2 sets per exercise) the low and medium volume training do in fact appear to be superior to support their regular sports specific training program. After all, mere strength is not so much of an issue in either soccer or volleyball; and given the fact that at least for soccer the lower limb power is what really counts, a low volume strength training approach would, aside from obviously being highly economic, also yield the most pronounced sport specific performance increases.

It stands to reason: If neither brute strength nor tons of muscle are your goal and strength training is just an adjunct to your sports-specific training, high volume sucks!

Whether the surprising superiority of the low volume routine as a 'average strength builder'  for soccer and volleyball players does mean that legs need less, rather than more work than the chest, which appears to like the constant hammering, is however highly questionable. In fact, this is where the bias of previous training comes into play. For both volleyball and soccer players, the latter does obviously include a hell lot of 'leg work' and while you do push-ups in soccer (and I guess volleyball as well), there is no training component that would correspond to the sprinting and HIIT exercises that involve the legs only. Now, of the latter you know that they can in fact have 'anabolic' effects on skeletal muscle. These may not be so immediate as they would be for someone doing a BB-like hypertrophy training, but they accumulate over time; and with three years of more or less 'professional' training in their respective sports, we may savely assume that all participants had their share of muscular hypertrophy in the quads, glutes and hams.

Moroever, skeletal muscle hypertrophy and strength gains require a certain degree of overload. Allegedly, when the training induced or the overall stress becomes too much, your training won't yield the desired results either. For someone whose main goals are skeletal muscle hypertrophy and strength gains, and who does not compete in any other sports that requires separate training,  the data from the study at hand would yet still support Arnold's way of doing "just one more set " - as long, as this is done in conjunction with adequate rest not just in-between sets, but in-between workouts, as well!

I can however guarantee you that doing 27 sets today and another 27 tomorrow, just to follow that up by some HIIT on day 3, in order to have a "day off" without a guilty conscience and to be "recovered" to do chest shoulders and biceps, your day 1 on day 4 again (thus starting another "cycle"), will yield neither muscle, nor strength gains. It will simply burn you out and pave your way right into the Athletes' Triad.

References:

• Naclerio F, Faigenbaum AD, Larumbe-Zabala E, Perez-Bibao T, Kang J, Ratamess NA, Triplett NT. Effects of different resistance training volumes on strength and power in team sport athletes: a pilot study. J Strength Cond Res. 2012 Oct 5.

"Just One More Set" (1/2): Metabolic Response to 10,000kg vs. 20,000kg Regimen. EPOC: Do Reps and Loads Both Figure? And What About Elite Athletes Do They Need More?

"Ah come on, just another set!" ... "I don't know man, we've already pumped away 100,000kg today... do you really believe that's going to be productive, I mean, yeah, we are cuttin', but still... I mean I don't dig this epic!", "EPOC man, it's called EPOC!" *shakes his head* "Call it whatever you want, bro, I am out!"

If you want, you can think of today's SuppVersity post as an extension to yesterday's "Bigger, Stronger, Faster" special of the On Short Notice series; to be more precise: As a practically more relevant version of the rodent study on hypertrophy vs. strength training that was part of the aforementioned post. Yep, we are "talking volume" today. How much is too much?  And though this is never-ending debate, it appears that at least as far as research goes, a little more debating certainly would not hurt. Therefore I am happy to have not one, but two studies for you which don't just address this issue, but have also been conducted with human subjects!

In view of the fact that these are no "short notices", I will discuss one today and the other tomorrow - yep, that means that you can already make a mental note to come back tomorrow ;-)

"Just one more set, ..." - how productive can that be?

Today's study comes from the Human Performance Laboratory at the Florida State University and deals with the energetic side of things - specifically the often-cited EPOC (excess post-exercise oxygen consumption), which is often touted as one of the most important aspects why strength training in general and higher volume / intensity strength training, in particularly, would have the edge over cardio training. The reasoning is easy: You don't burn so much energy while you work out, but in the time after, your body will (a) still expend more energy per minute / hour and (b) has the advantage of emptied glycogen stores, which will force it to tap into its body fat stores the source for the required energy.

All of you who have read the complete Athletes' Triad series, will by now already know that at least argument (b) is pretty idiotic, because it wouldn't allow you to replenish your muscle and liver glycogen after workouts and thus pave the way into the dreaded vicious circle of the athlete's triad. The former argument, on the other hand has - on a way more general level - only been confirmed a couple of days ago (see "Scientists resolve the paradox of stable muscle metabolism but greater mitochondrial respiration in muscle of inactive vs. active subjects", read more), the question still remains: How much weight do you have to lift to set the 'afterburner' into full gear? 

10 metric tonne or 20 metric tonnes? What do you say?

I see, you are laughing, but basically the above question is what the George J. Abboud and his colleagues tried to find out, when they recruited 8 healthy men aged19-29 yrs who had 

"at least 12 months of RT experience with no more than 2 wks rest at a time, less than a total of 4 wks off within the last 6 months, or 9 wks off within the last 12 months [and] reported no prior or current use of illegal performance enhancing substances." (Abboud. 2012)

Suggested read "Three is More Than One: Higher Volume Increases Strength Gains in Legs, and Satellite Cell Recruitment and Fiber Size in Legs & Traps."

As usual the subjects had to fill food logs for the three days before the testing and were instructed to replicate the same eating pattern on the second occasion in which they were randomly assigned to perform a standardized resistance training (RT) regimen consisting of 4 exercises performed on a non-counterbalanced smith machine so that the range of motion during

• bench press, 
• squat, 
• bent-over row and 
• Romanian deadlift 

could be controlled for easily. Other than the equipment and the exercises, which were identical on both occasions, the volume of the training sessions varied and if you express this volme in kg or metric tons, it was a competition of 10,000 kg (10 metric tonnes) vs. 20,000 kg (20 metric tonnes) of weight. 

"The loads were divided between the 4 exercises as follows: 35% to squats, 30% to bench press, 20% to bent-over rows and 15% to Romanian deadlift. For each set, subjects lifted approximately 85% of their 1RM for 6-8 repetitions. If 6 repetitions could not be completed at any point, the load was reduced by 10% for the subsequent set." (Abboud. 2012)

Both sessions were supervised by three testers : One monitored the metabolic cart, one made sure the proper range of motion was used and one monitored the proper lifting form. The subjects had to perform the concentric portion of each lift with maximal speed and ensure a controlled eccentric descent. A specific time interval was not dictated. Sets were stopped if "subjects broke form" (Abboud. 2012) and 2 minutes of rest were given between sets. In this fashion the subjects simply kept lifting set after set until the volume prescription for the respective trial was reached.

Figure 1: Resting metabolic rate (RMR) per kg body weight, 30min energy expenditure and respiratory exchange ratio (RER; lower values = higher fat, lower glucose  oxidation)  after low and high volume trial (based on Abboud. 2012)

As you can see in figure 1 there were differences as far as the effects of the high (20,000) vs. low (10,000kg) regimen on the resting metabolic rate, 30 min energy expenditure, and the respiratory quotient (lower values = higher fat, lower glucose oxidation), but in view of the fact that the high volume group moved 2x more weight and should thus (at least theoretically) have expended twice the energy (assuming they performed all reps with perfect form and identical speed), those differences are more than disappointing. 

The minuscle effect size is yet not the most "disappointing" (or "surprising" ?) result

In fact, contrary to the low volume workout the 20,000kg workout did not produce any increases in resting metabolic rate and 30min energy expenditure, at all - put simply: There was no EPOC after the high volume training. And this did not change over the whole 48h period (and I know you guys, you won't rest longer anyway ;-).

Now you may say that this was a crazy protocol, but let's do the math, let's assume the guys did squat 100kg, benched and rowed their own body weight of ~80kg and deadlifted 125kg. With 10 reps per set thats 1,000kg + 2x800kg + 1,250kg per set respectively. If they did three sets per exercise they would thus already be up to 9,950kg! If you still think that's crazy, let's hear what the scientists have to say:

"As subjects in the present study were well adapted to RT, the training stimulus needed to elicit increases in EPOC arguably needed to be much higher compared to that used in previous research  Two studies using intensities of 70% 1RM report significant increases in RMR. Melby et al. had subjects perform 6 setsof 10 different exercises for a total of 60 sets. The repetition range for this protocol was 8-12 repetitions per set. This amounts to approximately 600 repetitions performed during the course of the exercise bout. The range of load-volume lifted by these subjects was 15,000-38,000 kg. [...]" (Abboud. 2012)

The list goes on and you just have to go to your gym and I guarantee you, no matter how few people are on the floor you will see a guy who (often without noticing is) will be pounding away much more word within a single workout. Moreover, the the subjects in the present study completed their trials
with a drastically lower number of repetitions -  a mean of 199. Had they performed the crazy rep-volume of the Melby study, they would probably have come close to 50,000 kg. This raises an interesting question is "volume" correctly defined by giving the total amount of weight you lift? Or is the number of reps maybe more important as far as the after-burner EPOC is concerned?

Too much of a good thing? But what if you are a highly trained athlete?

A previous study, by Hackney et al. would support the notion that heavy lifting is an obligatory part of the EPOC equation. In the latter study, EPOC trained individuals who used a lower load-volume than the trainees in the study at hand  had increased resting metabolic rates for up to 72h (Hackney. 2008). Since the Hackney study also put an emphasis on eccentric contractions and will thus probably have lead to even greater muscle damage than the protocol of the study at hand (CK(10,000kg) = 729U/L vs.CK(20,000kg)  = 1,159IU/L), Abboud et al. speculate that ...

"[a]s protein synthesis required for repair is energetically expensive, it is logical that untrained subjects will show greater and longer alterations in EPOC post-RT. Judging by training history, strength levels and CK responses, subjects in the present study had most likely reached a higher level of adaptation than ones in previous studies, and therefore were less sensitive to the metabolic effects of recovery from RT." (Abboud. 2012)

In other words, for you, probably a seasoned strength trainee, the 'more is more' principle is not going to yield better results - even if your goal is to shed body fat. And ...

"Although RT is an important component in any weight loss program to attenuate the loss of fat free mass and therefore better preserve RMR, it is unlikely that the total energetic cost (during and post-exercise) of a typical duration workout will be adequate for significant weight reduction in highly trained recreational lifters without caloric restriction and/or additional aerobic or high intensity interval training." (Abboud. 2012)

And since I rarely encounter a conclusion that's so to the point, I'll leave you with that for today and remind you to come back tomorrow to learn, when and for which body parts doing somewhat more may still be beneficial - read me tomorrow ;-)

References:

• Abboud GJ, Greer BK, Campbell SC, Panton LB. Effects of Load-Volume on EPOC after Acute Bouts of Resistance Training in Resistance Trained Males. J Strength Cond Res. 2012 Oct 18.
• Hackney KJ, Engels HJ, and Gretebeck RJ. Resting energy expenditure and delayed-onset muscle soreness after full-body resistance trainingwith an eccentric concentration. J Strength Cond Res. 2008; 22: 1602-1609.
• Melby C, Scholl C, Edwards G, and Bullough R. Effect of acute resistance exercise on postexercise energy expenditure and resting metabolic rate. J Appl Physiol. 1993; 75: 1847-1853.