ABSTRACT
In the past decades, the genetic basis for athletic performance and response to exercise training (trainability) has become a topic of great interest. Twin and familial studies have shown that part of the interindividual variability reported in sports science studies can be explained by the genetic makeup of individuals (16). Although humans’ DNA sequences are similar at 99.9%, genetic mutations are found across the genome at a rate of approximately 1 change per 1000 base pairs. Some of these mutations consist of the replacement of a single nucleotide by another and are referred to as single nucleotide polymorphisms (SNPs). Those SNPs can be rare (occur at a frequency <1%) or common (occur at a frequency >1%) within a given population. Each human carries 3–4 million common variants and 200,000–500,000 rare variants, and some of these variants are involved in athletic performance and trainability. To discover those variants, initially candidate gene approaches and then later genome-wide association studies (GWAS) were conducted (Figure 24.1). To date, more than 200 genetic variants have been associated with athletic performance or trainability in at least one study (1, 10, 14, 22, 52, 53, 65). These findings suggest that athletic performance and trainability are not determined by a single gene but by a plethora of genes and are therefore considered complex traits. In this chapter, we will summarize the findings on genetics and sport performance and we will discuss some of the current research efforts that are undergoing to further characterize “exercise genes.”348
