An increase in muscle size with exercise may not be directly related to an increase in muscle strength, according to a recent analysis of the literature.
Investigators who examined available evidence have concluded that size and muscle strength may actually be separate phenomena, which challenges many assumptions upon which exercise programs have been based. The researchers noted that there is a weak correlation between change in muscle size and change in muscle strength following training. Also, there is a loss of muscle mass with detraining, yet often a maintenance of muscle strength. Furthermore, similar muscle growth can occur with low load or high load resistance training, yet there are divergent results in strength.
"As the story goes with exercise-induced changes in strength, neural adaptations are contributing first with muscle growth playing a more prominent role in the latter portion of a training program: however, there is little direct evidence that this is actually true in an adult partaking in a resistance training program," said Dr. Jeremy Loenneke, senior author of the Muscle & Nerve article. "Our paper highlights many potential issues with how we think about changes in strength following exercise."