The AKT1 gene codes for an enzyme related to muscle building and metabolism. Some of us carry a particular version of this gene that is linked to better resting metabolic factors and greater increases in VO2 max in response to aerobic exercise. Your FitnessGenes result tells you which version of this gene you carry.
The AKT1 gene contributes to the expression of the AKT1 enzyme (also known as PKB-α), which is an important molecule involved in the regulation of multiple processes including muscle growth and metabolism. It is believed to be a mediator of insulin function and enhances glucose uptake in muscle, fat cells and liver cells, amongst others. One particular version of this gene is believed to affect our baseline metabolic processes and response to exercise. Experiments have shown that increased expression of the AKT1 gene has an anabolic (growth) effect on muscle and bone, while reduced expression has a catabolic (breakdown) effect on fat.
Source: 1000 Genome Project. Global averages for both sexes