Physiology The ACE gene and muscle performance

Angiotensin-converting enzyme in human skeletal muscle can be encoded by either of two variants of the ACE gene, one of which carries an insertion of 287 base pairs. This longer allele gives rise to lower enzyme activity, and is associated with enhanced endurance performance and an anabolic response to intense exercise training. Here we examine training-related changes in the mechanical efficiency of human skeletal muscle (energy used per unit power output) and find that the presence of this ACE allele confers an enhanced mechanical efficiency in trained muscle.