Fitness training outcomes linked to gene variants

Key gene variants linked to running success have been identified in a small study on previously untrained participants.

In the study, scientists investigated genetic associations with cardiorespiratory fitness following an endurance-based running programme. They discovered that 18 single nucleotide polymorphisms (SNPs) were positively associated with an above-average increase in running distance. This improvement also positively correlated with the number of these genetic polymorphisms a person had.

Dr Henry Chung, from the School of Sport, Rehabilitation and Exercise Sciences at the University of Essex said: 'This study supports the fact that genetics play a major part in athletic performance and training responses… Whether you are an elite competitor or training for a fun run, your DNA can make a real difference on how much you can push your limits'.

Scientists recruited 45 participants in the UK aged between 20 and 40. Divided into two random groups, the first group were prescribed a strict, eight-week endurance-based running programme consisting of a 20-30 minute outdoor run three times per week. The second group was the control group, where participates continued with their normal daily routine.

At the beginning, middle and end of the study, all participants took a test to measure their running ability and aerobic fitness. The Cooper run test demonstrates the maximum distance a person can run in 12 minutes.

At the end of the running programme, all participants gave a saliva sample for genotype analysis where 1000 SNPs were assessed.

The group that undertook the endurance training improved their Cooper run test score by an average of 11.5 percent. The control group, showed little or no improvement. However, the people within the endurance training group improved at different rates: some could run approximately 20 percent more, while others didn't improve at all after the eight weeks of training.

The scientists explained that these differences were due to how many of the 18 SNPs an individual possessed, which were directly associated with the endurance improvements. As such, identifying genetic polymorphisms provides a deeper understanding to the influence of genetics on an individual's responsiveness to endurance training.

The scientists specifically conducted an allele-specific analysis, rather than selecting common well-explored candidate genes.

Publishing their results in PLOS ONE, the scientists wrote '… to our knowledge this is the first study to have established a relationship between cardiorespiratory fitness and allele-specific genotypes using field-based measures and training.'

However, they also suggest that a larger sample size is necessary for genetic analysis and is a limitation of this study.