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Performance Area => Peer Reviewed Studies Discussion => Topic started by: Zetz on July 24, 2011, 01:24:44 am
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http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0012033
Overview:
Background
We aimed to determine the effect of resistance exercise intensity (% 1 repetition maximum—1RM) and volume on muscle protein synthesis, anabolic signaling, and myogenic gene expression.
Methodology/Principal Findings
Fifteen men (21±1 years; BMI = 24.1±0.8 kg/m2) performed 4 sets of unilateral leg extension exercise at different exercise loads and/or volumes: 90% of repetition maximum (1RM) until volitional failure (90FAIL), 30% 1RM work-matched to 90%FAIL (30WM), or 30% 1RM performed until volitional failure (30FAIL). Infusion of [ring-13C6] phenylalanine with biopsies was used to measure rates of mixed (MIX), myofibrillar (MYO), and sarcoplasmic (SARC) protein synthesis at rest, and 4 h and 24 h after exercise. Exercise at 30WM induced a significant increase above rest in MIX (121%) and MYO (87%) protein synthesis at 4 h post-exercise and but at 24 h in the MIX only. The increase in the rate of protein synthesis in MIX and MYO at 4 h post-exercise with 90FAIL and 30FAIL was greater than 30WM, with no difference between these conditions; however, MYO remained elevated (199%) above rest at 24 h only in 30FAIL. There was a significant increase in AktSer473 at 24h in all conditions (P = 0.023) and mTORSer2448 phosphorylation at 4 h post-exercise (P = 0.025). Phosporylation of Erk1/2Tyr202/204, p70S6KThr389, and 4E-BP1Thr37/46 increased significantly (P<0.05) only in the 30FAIL condition at 4 h post-exercise, whereas, 4E-BP1Thr37/46 phosphorylation was greater 24 h after exercise than at rest in both 90FAIL (237%) and 30FAIL (312%) conditions. Pax7 mRNA expression increased at 24 h post-exercise (P = 0.02) regardless of condition. The mRNA expression of MyoD and myogenin were consistently elevated in the 30FAIL condition.
Conclusions/Significance
These results suggest that low-load high volume resistance exercise is more effective in inducing acute muscle anabolism than high-load low volume or work matched resistance exercise modes.
Link has the full study.
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Unfortunately that study kinda sucks :(
You'd need to do a multi week study using compound exercises...
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No it's a good study, but it's odd, because who ever promoted using 90% 1RM for hypertrophy. They should have used 65%.
Also, I read the full text a while ago, and the 90% 1RM induced the same increases in protein synthesis 24 hours after the workout, but not at 48.
Since the total work performed from the 30% was so much greater, maybe the correct conclusion is that per amount of work performed, 90% 1RM is better for protein synthesis. Id I remember correctly they did take short rest periods right? That would play a huge role.
So the conclusions of the study are one and many
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The point is that none of the conclusions you can make are relevant to those of us who are interested in training.
They compared using 30% vs 90% of 1RM one time. If your training plan is to be "recreationally active" for eight weeks and then perform a new exercise one time at 30% or 90% and you can't decide which is a better choice then this study might be useful. However, nobody here trains like that. The first time you do an exercise 90% will quickly turn into 70% within a matter of weeks. Additionally beginners don't have the neuromuscular coordination to perform an exercise with 90% of their true 1RM. We really should not make conclusions about a study that was performed once as to how it relates to repeated progressive overload which is what most people here use.