Tuesday, March 22, 2011

Muscle Building Takes Time. Less in Newbies, Though: 9.6% More Muscle in 8 Weeks

"Patience is a virtue!" Many bodybuilders and fitness enthusiasts have to learn this the hard way - even on drugs, muscles won't grow (hypertrophy) within days and visible gains in lean muscle mass will take years or month. Although the results of a recent study (DeFreitas. 2011) done by scientists from the University of Oklahoma won't help to overcome the delay between training induced muscle stimulus and physiological hypertrophy response, the observations of DeFraitas et al. are nevertheless interesting.

By the means of weekly testing the scientists wanted to determine the "precise time course of skeletal muscle hypertrophy" in response to 8 weeks on a specifically designed high intensity resistance training program in 25 healthy, sedentary men. The measured outcomes were whole muscle cross-sectional area (CSA) of the dominant thigh (via computer tomography) and isometric maximum voluntary contractions (MVC). 
After only two training sessions (W1) [=week 1], the mean thigh muscle CSA increased by 5.0 cm² (3.46%; p < 0.05) from the pre-testing (P1) and continued to increase with each testing session. It is possible that muscular edema may have inXuenced the early CSA results. To adjust for this possibility, with edema assumedly at its highest at W1, the next significant increase from W1 was at W3. W4 was the Wrst signiWcant increase of MVC over P1. Therefore, signifcant skeletal muscle hypertrophy likely occurred around weeks 3–4.
While edema, unquestionably, are one possible reason for the sudden increase in "muscle mass" being a 'sedentary newbie' to strength training may well be another factor contributing to the immediacy of the muscle gains (do not expect to see similar results as an experienced athlete!). The scientists reliance on sedentary subjects compromises the significance of the whole study (in view of what athletes and gymrats may expect), thus the measured overall gains, impressive +13.9 cm² (9.60%) CSA, appear hardly transferable to a "reasonably" trained group of subjects, as well.
Figure 1: Development of muscle size (measured as CSA of thigh muscle) and force (measured as MCV) in 25 formerly sedentary subjects on an 8 week high intensity strength training program (DeFreitas. 2011)

Comment: Its really a pitty that out of monetary and organizational reasons all these studies are done on newbies, whom you could send work on a construction site for 8 weeks and see immense gains in strength and muscles, when they do not get hit by a block of concrete. So, do not feel discouraged if - in the course of the whole last year, you did not gain +13.9 cm² in your tigh muscle. You are probably just to athletic already ;-)