In comments to this post about low versus high reps for muscle growth, Anoop said “8 sets of 8 reps have shown to elevate synthesis upto 24 hrs in the post fed state.”  That is much more volume than I am doing.  In one session for chest, I might only perform 3 sets of 8.

I started to wonder if there were other studies that covered this topic using different protocols, so I might have some idea how muscle protein synthesis acts with various volumes/workloads.  As you will recall, Anoop also stated in the comments, “The volume of 3*8 reps & 6 sets of 3 is lower than usual. And the protein synthesis came back to basal levels after 2 hrs.”

Study 1:
Chesley A, MacDougall JD, Tarnopolsky MA, et al. Changes in human muscle protein synthesis after resistance exercise. J Appl Physiol 1992; 73: 1383-8

This study had 12 healthy males “who regularly engaged in resistance training” perform “four sets of 6-12 repetitions of the biceps curl, preacher curl, and concentration curl with a resistance equal to 80% of the 1 RM. All sets were performed to muscular failure, and rest periods of 3 min were provided between sets and exercises.”  The results were that muscle protein synthesis was elevated by ~50% at 4 hours, and ~100% at 24 hours.

Study 2
MacDougall JD, Gibala MJ, Tarnopolsky MA, et al. The time course for elevated muscle protein synthesis following heavy resistance exercise. Can J Appl Physiol 1995; 20: 480-6

This study had 6 males (I am not sure if they are trained or untrained) perform 12 sets of biceps curls in the 6 to 12RM range.  I asssume that they followed the same protocol as outlines for the study above, but I do not know that.  This study determined that muscle protein synthesis is within 14% of baseline levels 36 hours after the resistance exercise session.

My Thoughts/Questions:

1) 72 to 144 total repetitions performed over 12 sets taken to concentric failure?!  Wernbom advises 30 to 60 repetitions per session, and 2 to 3 sessions per week, but, as we saw above, 3 sets of 8 (or 24 total reps, just shy of Wernbom’s 30 rep cut-off) only seems to increase protein synthesis for 2 hours following an exercise session.  Would 30 repetitions for a muscle really do much more than 24?  I am only trying to point out that it seems like Wernbom’s recommendations would only cause muscle protein synthesis to spike for a short time after a workout.

3) It doesn’t seem advisable to me to try and replicate the protocols described above to exercise the entire body two times per week.  Does anyone have any thought about this?

I remember Bryan presents on his forum data that on trained protein synthesis lasts shorter then untrained

back to basal after 2 hours is pretty short lasting.. Don’t know if it had as much to do with the volume and intensity as with amino acid availability, though.

In this study (also fasted, actually), MPS was elevated at 12 hours post exercise with 4 sets of 8-10 reps with the last set being performed to failure.
http://jp.physoc.org/content/568/1/283.abstract
This used fractional, so it investigated myofibrillar protein synthesis, not just mixed muscle.
This happened in trained subjects (trained for 8 weeks)

In this study (fed)
http://ajpregu.physiology.org/cgi/reprint/294/1/R172
6 sets with 6-8RM
elevated MPS in trained (trained for 8 weeks) at 4 hours, but back to baseline (no statistical difference between rest and 24h post training) at 24 hours. The elevation was so large at 4 hours that I think the MPS stayed elevated for some time after 4 hours. But the study only does 2 measurements.

I’m kind of confused now.. How much volume do I need if I want to keep MPS elevated for the longest possible period of time? Was the difference between the fasted 2 hour back to baseline and the 12 hour still elevated studies in the exercise protocol? Maybe doing 3 sets isn’t enough? But then again, I think most meta analyses on number of sets find that 3 sets work very well for hypertrophy..

Karky - 12 May 2010 01:42 PM

back to basal after 2 hours is pretty short lasting.

The peak was at 1-2 hours post exercise, and then MPS declined back to basal levels afterwards.  Still short, but not that short. 

Karky - 12 May 2010 01:42 PM

In this study (fed)
6 sets with 6-8RM
elevated MPS in trained (trained for 8 weeks) at 4 hours, but back to baseline (no statistical difference between rest and 24h post training) at 24 hours. The elevation was so large at 4 hours that I think the MPS stayed elevated for some time after 4 hours. But the study only does 2 measurements.

Is there a link to this study you mention above (the second study).  Does it mention whether the test subject perform their sets to concentric failure?

Karky - 12 May 2010 01:42 PM

I’m kind of confused now.. How much volume do I need if I want to keep MPS elevated for the longest possible period of time? Was the difference between the fasted 2 hour back to baseline and the 12 hour still elevated studies in the exercise protocol? Maybe doing 3 sets isn’t enough? But then again, I think most meta analyses on number of sets find that 3 sets work very well for hypertrophy..

These are my thoughts exactly!  In the protocol mentioned in my OP (3 sets of 8 at 75% on 2 minutes) the test subjects may not have actually lifted to failure.  Is this why lifting to failure is so important?  Does lifting to concentric failure provide the stimulus necessary for long lasting MPS?  The second and third protocols in my OP had multiple sets to failure, and the 1st study you mentioned also had the last set to failure.

Incidentally, here is another study on this subject.  I only have the abstract, but to summarize: 8 untrained subjects performed “eight sets of eight concentric or eccentric repetitions at 80% of each subject’s concentric 1 repetition maximum ... Exercise resulted in significant increases above rest in muscle FSR at all times: 3 h = 112%, 24 h = 65%, 48 h = 34% (P < 0.01).”

Anoop, is this one of the studies you refer to when you mentioned the 8*8@80% protocol elicited increased MPS beyond 24 hours after exercise?

Also, can someone explain the difference between “muscle protein synthesis rate,” and “Mixed muscle protein fractional synthesis rate”?

Well, fractional protein synthesis is the protein synthesis in one fraction of proteins, for example myofibrillar (actin and myosin). It should say which fraction, if it doesn’t in the abstract, I’m sure it does in the full text.

I think “muscle protein synthesis rate” refers to mixed muscle protein synthesis, which is the synthesis in all muscle proteins.

Oops, forgot the link to that second study. I edited it in now. (http://ajpregu.physiology.org/cgi/reprint/294/1/R172)
Doesn’t say anything about failure or not

As for failure. I don’t know if that would be the stimulus itself.. IE, would there be a huge difference between going 1 rep shy of failure and actually going to failure? I do think that how close you come should mean something, though. If a set is very light, maybe 3-4 reps shy of failure, i think it won’t bring about a long lasting increase in MPS.

Karky - 12 May 2010 04:57 PM

As for failure. I don’t know if that would be the stimulus itself.. IE, would there be a huge difference between going 1 rep shy of failure and actually going to failure? I do think that how close you come should mean something, though. If a set is very light, maybe 3-4 reps shy of failure, i think it won’t bring about a long lasting increase in MPS.

Clearly, you are right about concentric failure ... I guess it goes back to the pretty simple idea of fatiguing the fast twitch fibers enough to elicit a growth response.  If you perform enough work at a certain intensity and above, you will cause an upregulation of muscle protein synthesis.

As we saw in the first study of the OP, 3 sets of 9 on 2 minutes rest, with reps performed on a 1 to 2 second controlled concentric and eccentric was enough to cause as much MPS increase in the test subjects as the two higher intensity protocols.  I believe I have also read elsewhere that intensities as low as 40% can cause HTMU to be recruited from the first rep if the weight is moved as fast as possible.  I believe this indicates that intensities even lower than 60% can be just as effective as the 60% to 90% intensity range if the weight is accelerated as much as possible and enough volume is performed to fatigue the HTMU.

Chad Waterbury fairly recently proposed the idea that one should just lift the weight as fast as possible (with proper form) until the bar speed slows down (I can’t really say whether this is solely his invention or not), but I am starting to think that there may be some credence to this idea.  If you consider that a heavy enough weight, moved as fast as possible, will require all HTMU to be fired from the beginning of the first rep, then wouldn’t a slowing rep speed indicate that some of the HTMUs had been fatigued enough for those units to have “failed”?

I definitely think speed has something to say, specially with regards to activating MUs.. but MU activation doesn’t equal protein synthesis.
I think muscle tension plays a pretty big role here.. Usually, more activation means more muscle tension because you’re using more weight. But if you’re just using more speed you’re not getting that much more muscle tension out of it. So while you’re activating as many MUs as in a really heavy lift, you’re not getting as much tension as in a really heavy lift.

Usually, most protein synthesis studies have used around 8-10 sets of 8-12 reps. So most studies tend to follow that route. If they deviate it is usually because of some special circumstances like equalizing volume and such. And in studies, they do not do any warm up sets.

I will write more later.