Genetics, Muscle Morphology, and the Myth of Talent: Insights from Twin Studies on Athletic Potential
Short Abstract
Today, we explore one of the oldest debates in sports: is athletic talent something you’re born with or something you build? The truth lies in the combination of genetics, muscle morphology, and environment. While certain genes like ACTN3 (linked to sprinting) and ACE (linked to endurance) influence athletic traits, they alone don’t create champions. Genetics accounts for about 40–50% of traits like VO₂max and strength, leaving plenty of room for training, environment, and motivation to shape outcomes. Muscle morphology — including fiber type, muscle size, and tendon properties — is also partly genetic, but adaptable. Studies show consistent training can increase fast-twitch fibers or reshape muscle structure. Athletes like Rebecca Romero, who medaled in both rowing and cycling, prove it’s possible to succeed in entirely different sports by reshaping one’s physiology. Twin studies offer valuable insights into nature vs. nurture. Identical twins share 100% of their genes, yet those with different training regimens often achieve different fitness levels. This confirms genetics is not destiny. In the end, athletic success comes from the synergy of three factors: genetics, muscle structure, and environment/training. Potential is just a starting point — what truly defines an athlete’s path is how they develop it.
Short professional biography (CV)
Johnny Padulo is an Associate Professor at the University of Milan (since 2019), specializing in “Methods and Didactics of Sports Activities.” His research focuses on training theory and methodology, youth and school sports development, athletic performance assessment through morphological, physiological, and psychological parameters, and movement analysis for both general populations and athletes, including those with disabilities. He also works on injury prevention, sports nutrition, anti-doping ethics, and inclusive sports education. His academic output is substantial: 259 peer-reviewed papers, over 6,100 citations (Scopus), an h-index of 43, 17 indexed abstracts, 66 conference proceedings, 2 monographs, and 4 book chapters. He’s received 18 scientific awards, led 11 funded research projects, and serves as Editor in Chief for ACTA KINESIOLOGICA. Additionally, he’s an Associate Editor for 11 journals, reviewer for 67, and active in 4 scientific societies. He’s presented at 87 conferences and holds 4 patents.
Links to personal website or scientific profile:
https://orcid.org/my-orcid?orcid=0000-0002-4254-3105
https://www.researchgate.net/profile/Johnny-Padulo?ev=hdr_xprf
https://www.unimi.it/it/ugov/person/johnny-padulo