Protein synthesis has a shorter duration


Resistance training alters the response of fed-state mixed muscle protein synthesis in young men.
(Borge Fagerli @ Nov. 24 2007,12:16)</div><div id="QUOTEHEAD">QUOTE</div><div id="QUOTE">Previous studies have shown that the increase in protein synthesis (formation of new muscle tissue) is relatively short-lived after a workout - after about 48 hours (2 days) is almost back to the starting point and beyond 3 days, it is primarily structural repairs that are active.

This study shows the effect of the so-called Repeated Bout Effect (RBE), which says that regular exercise has a protective effect on muscle, and the response after a workout are becoming smaller and more short-lived. The study was over 8 weeks, subjects trained one leg with bone park (leg extension) while the other leg served as control and was not trained. Training program was as follows:

Bein Park 3x per week
weeks 1-2: 3 sets 10/12 reps
weeks 3-4: 4 sets reps 8.10
weeks 5-6: 5 reps Set 8.10
Week 7.8: 6 reps Set 6.8

Protein synthesis increased in both legs (it's systemic), but increased most in the leg that was trained. Muscle mass increased only in the trained leg. After 8 weeks so one that protein synthesis was back to zero after only 28 hours in the trained leg (ie just over one day), but in the untrained leg protein synthesis was still increased by 70 + / - 49% (ie up to 120%).
This makes it even more obvious that you do not have to sacrifice exercise frequency - to train each muscle once per week is too rare and one can not compensate by running the 20-30 set, either, it gives little or no additive effect when you have reached a certain minimum.
I have recommended åresvis advanced and advanced lifters that they at least train each muscle group every 5 days, and preferably two, up to three times a week - then you will also be able to work both with a match volume and follow a regular load progression. This training rate you find again in the effective training programs that HST, DC, and 5x5.

Am J Physiol Regula Integr Comp Physiol. 2007 Nov 21
Resistance training alters the response of fed state mixed muscle protein synthesis in young men.
Tang JE, Perco JG, Moore DR, Wilkinson SB, Phillips SM.
Kinesiology, McMaster University, Hamilton, Canada.
Ten healthy young men (21.0 + / - 1.5 yr, 1.79 + / - 0.1 m, 82.7 + / - 14.7 kg, mean + / - SD) participated in eight weeks of intense unilateral resistance training (knee extension exercise) such that one leg was trained (T) and the other acted as an untrained (UT) control. After the eight weeks of training, infusions of L-[ring-d5] phenylalanine, L-[ring-(13) C6] phenylalanine, and d3 alpha-KIC were used to measure mixed muscle protein synthesis in the T and UT legs by the direct incorporation method (FSR). Protein synthesis was determined at rest, 4 and 28 h after an acute bout of resistance exercise performed at the same intensity relative to the gain in strength before and after training. Training increased mean muscle fiber cross-sectional area only in the T leg (type I: 16 + / - 10%, type II: 20 + / - 19%, P &lt;0.05). Muscle protein FSR in both legs at 4 h (T: 162 + / - 76%; UT: 108 + / - 62%, P &lt;0.01 versus rest) with the increase in the T leg being significantly higher than in the UT leg that this time (P &lt;0.01). At 28 h post-exercise, FSR in the T leg had returned to resting levels, however, the rate of protein synthesis in the UT leg remained elevated above resting (70 + / - 49%, P &lt;0.01). We conclude that resistance training attenuates the protein synthetic response to acute resistance exercise, despite higher initial increases in FSR, by short projection the duration for which protein synthesis is elevated.

From the study:
The leg to be trained was selected Randomly, counter-balanced for dominance based on strength, such that equal numbers of subjects trained their dominant and non-dominant legs. Training was performed 3 d · wk-1 (Monday to Friday) initially (weeks 1-4) and then only 2 d · wk-1 at the latter stages of the training (weeks 5-8); at least one day of rest was provided between each training session. For weeks 1-2, training began with three sets of knee extension exercise performed at a workload equivalent to each subject's 10.12 RM. For weeks 3-4, participants performed four sets that their 8.10 RM. The number of sets was increased to five for weeks 5-6. Finally, for 7.8 weeks participants performed six sets at a workload equivalent to their 6.8 RM.</div>