What do studies say about Sportgene Training?

Scientific evidence for so-called 'Sportgene' tests is weak. Most claimed associations between single gene variants (e.g., ACTN3, PPARGC1A) and training outcomes come from small studies or GWAS with small effect sizes. Even if a test shows a 'favorable' profile, it does not allow individually optimized training. Training adaptation is multifactorial: genetics play a role, but nutrition, sleep, recovery, and training programming are far more important. Moreover, longitudinal studies proving that training plans based on such tests outperform general principles are lacking. MyBody-X tests provide hints at best, not training prescriptions. Beware of exaggerated marketing claims. Evidence: marketing/unclear.