ABSTRACT
It is well known that individual differences exist in exercise capacity or trainability. Several studies have shown that these individual differences are brought about by environmental effects such as life-style, diet and genetics. The potential of several specific genes to cause individual differences in endurance capacity or trainability has been investigated. The <I>angiotensin-converting enzyme (ACE) </I> gene, which has <I>insertion (I) </I> /deletion (<I>D</I>) polymorphism, is one of the most studied genes. Montgomery et al. reported that elite high-altitude mountaineers had higher <I>I</I> allele frequency of the <I>ACE</I> gene than did sedentary males. Moreover, they reported that subjects with <I>II</I> homozygotes showed higher trainability during a 10-week endurance training program than did individuals with <I>ID</I> heterozygotes or <I>DD</I> homozygotes. However, the results reported by Rankinen et al. did not support their results in terms of the relation between <I>ACE</I> genotype and cardiorespiratory endurance. Although numerous studies have reported a relationship between these two items, it remains controversial. Furthermore, mitochondrial DNA (mtDNA), the creative kinase and the <I>Na</I><SUP>+</SUP>-<I>K</I><SUP>+</SUP>-<I>ATPase</I> ∂<I>2</I> genes have been studied as genes that may dictate individual differences in endurance capacity or trainability. We are going to report about the relation between these genes and exercise capacity and trainability.