What can the Fitness Vitality DNA tell you — and what not?

The MyBody-X Fitness Vitality DNA test analyzes selected genetic variants associated with athletic performance, muscle building, recovery, and energy metabolism. For example, it looks at the ACTN3 gene (R577X), which influences muscle fiber type composition (power vs. endurance), and genes involved in fat and carbohydrate metabolism. The test can indicate tendencies, such as whether a person is genetically predisposed to sprint or endurance sports. What the test cannot do: It does not provide a definitive training regimen or diet prescription. The effect sizes of most genetic variants are small and are overshadowed by environment, nutrition, training, and lifestyle. It is supplementary information, not a medical diagnosis. The test also cannot predict injury risk or specific performance limits. The evidence is based on GWAS studies with moderate strength. For personalized training or nutrition planning, always consult a sports physician or exercise scientist.