Is Fitness All in the Genes?

 



 

Researchers from the Pennington Biomedical Research Center in Baton Rouge, La., and other institutions examined the genomes of 473 healthy white volunteers. All were part of the Heritage Family Study, an ongoing  examination of exercise genetics that already has provided information about whether various exercise traits tend to run in families.In such studies, researchers examine virtually the entire genome of people with various traits, often diseases. The aim is to discern whether tiny segments of DNA called single-nucleotide polymorphisms, or SNPs ("snips'') recur frequently in those with the traits. The presence of particular SNPs suggests that a particular snippet of the genome affects susceptibility to a disease or, in this case, exercise.The researchers looked at 324,611 individual snippets over all. Each of the volunteers completed a carefully supervised five-month exercise program, during which participants pedaled stationary bicycles three times a week, at controlled and identical intensities. Some wound up much fitter, as determined by the increase in the amount of oxygen their bodies consumed during intense exercise, others oxygen consumption showed little deviation.

No obvious, consistent differences in age, gender, body mass or commitment marked those who responded well and those who continued to huff and struggle during their workouts, even after five months. But, there was a divergence in their genomes. The researchers identified 21 specific SNPs, out of the more than 300,000 examined, that differed consistently between the two groups. SNPs come in pairs, providing 42 different individual versions of the 21 SNPs. Those exercisers who had 19 or more of these SNPs improved their cardiorespiratory fitness three times as much as those who had nine or fewer.

Obesity is a major risk factor for cardiovascular disease, diabetes, and osteoarthritis which affects over 25% of Americans. It is a know fact that losing weight can not be accomplished by dieting alone. Although more research is needed before it can be determined just how any particular gene influences the body’s response to aerobic exercise, this information can be very beneficial for our future and its' health.