By Daniel Gwartney, M.D.
There is a theme, just realized, shared between the two articles I have authored this month— the effect of pre-training on muscle response. In the “Fat Attack” column, the utility of training in the glycogen-depleted state to increase fatty acid burning is discussed. In summary, preceding a power or interval workout with a prolonged aerobic session (involving the same muscle group) by one to two hours, forces the muscle to activate fat-burning processes and creates more mitochondria (the energy factories in cells)— at least for the leg muscles.
For those who can accommodate the time demand, it seems a practical way to prime the fat-burning machinery. However, that protocol does not appear to support lean mass gains and might be detrimental to one-rep max (1RM) strength.
For the recreational lifter or non-competitive athlete, there is a pre-training technique that has demonstrated a significant increase in both 1RM and cross-sectional area (a measure of muscle size or girth). In a recently published study appearing in the European Journal of Applied Physiology, a group of researchers in Norway investigated the effect of increasing endogenous (i.e., natural, produced by the body) anabolic hormones, testosterone (T) and growth hormone (GH), via a specific leg workout prior to training the elbow flexors (biceps and brachialis).1 They controlled the experiment by training one arm twice a week (2 sets of three different exercises), and the other on two separate days (same arm workout, but preceded by 3 working sets of three leg exercises).
Before going into the results of the study [OK, training legs just before the arm workout gave greater 1RM and size gains], it will help to understand why this was considered a rational approach. Most people will agree, especially readers of this magazine, that elevating T and GH will produce increases in muscle strength and mass. This is well founded in science, along with the practical experiences of generations of athletes.2, 3 A loss of muscle mass and strength are symptoms of low T and/or GH levels secondary to aging or certain other conditions. The overtraining/overreaching syndrome of progressive performance loss is associated with a reduction in these hormones.4 Increasing T above the physiologic range through the use of exogenous (pharmaceutical) compounds reliably increases muscle mass. GH has not proven to be an effective strength promoter used singly, but in combination with T it appears to have an additive effect on muscle mass.5, 6 Notably, many aging men treated for GH deficiency report subjective improvements in muscularity, strength, and exercise tolerance.
Increasing muscle size and strength is more than merely boosting T and GH. A variety of factors are involved, including: mechanical loading and stress (e.g., lifting weights); relative energy and nutrient availability; endocrine (hormone) response; paracrine (local growth factors) response; and coordination.7 Though each factor singly can impact size and strength, the optimal response requires the factors to work in harmony.
The human body is designed to respond to its environment, though it interprets conditions through the “genetic eyes” of our forebears who would find the concept of exercising for recreation or weight loss bizarre. Just a few generations back, there were very few labor-saving devices, and most occupations involved physical exertion. The stimulus for growing muscle— to the survival-oriented gene pool, muscle is an energetically expensive tissue that needs to be limited to reduce the need for calories, is activation of a large muscle mass against a relatively heavy object. The concept of training a single muscle group is completely foreign to human DNA. It is inefficient, and when food is scarce and the most trivial injury can be life-threatening, smart cavemen and peasants did things the easiest way possible.