One one level this is pretty obvious. A 5 footer will not be competitive at pro basketball. Woody Allen no matter what training he did or even what drugs he took would never challenge Schwarzenegger. Doug McGuff discusses this frustration in an excellent article here.
But there is more than the frustration of a disillusioned bodybuilder. A new study indicates that some people simply do not benefit from aerobic exercise. For them, its effects are limited.
Using molecular classification to predict gains in maximal aerobic capacity following endurance exercise training in humans
A low maximal oxygen consumption (VO2max) is a strong risk factor for premature mortality. Supervised endurance exercise training increases VO2max with a very wide range of effectiveness in humans. Discovering the DNA variants that contribute to this heterogeneity typically requires substantial sample-sizes. In the present study we first use RNA expression profiling to produce a molecular classifier that predicts VO2max training response. We then hypothesised that the classifier genes would harbour DNA variants that contributed to the heterogeneous VO2max response. Two independent pre-intervention RNA expression data sets were generated (n=41 gene-chips) from subjects that underwent supervised endurance training. One identified, the second blindly validated an RNA expression signature that predicted change in VO2max ('predictor genes'). The HERITAGE Family Study (n=473) was used for genotyping. We discovered a 29 RNA signature that predicted VO2max training response on a continuous scale, and these genes contained ~6 new SNPs associated with gains in VO2max in HERITAGE. Three from 4 novel HERITAGE candidate genes were confirmed as RNA predictor genes (i.e. 'reciprocal' RNA validation of a QTL genotype), enhancing the performance of the 29 RNA based predictor. Notably, RNA abundance for the predictor genes was unchanged by exercise training, supporting the idea that expression was pre-set by genetic variation. Regression analysis yielded a model where 11 SNPs explained 23% of the variance in gains in VO2max, corresponding to ~50% of the estimated genetic variance for VO2max. In conclusion, combining RNA profiling with single-gene DNA marker association analysis yields a strongly validated molecular predictor with meaningful explanatory power. VO2max responses to endurance training can be predicted by measuring a ~30 gene RNA expression signature in muscle prior to training. The general approach taken could accelerate the discovery of genetic biomarkers, sufficiently discrete for diagnostic purposes, for a range of physiological and pharmacological phenotypes in humans.
The Press Release explains things well:
- Findings suggest aerobic exercise does not benefit everyone equally and may not help ward off heart disease and other potential ailments for some people.
- 20 per cent of normal people do not get any aerobic fitness benefit from following government guidelines.
- 30 per cent of people do not improve their metabolic fitness from following government guidelines.
- Genetic testing can tell if a person is likely to benefit from aerobic exercise, meaning healthcare specialists can appropriately personalise treatment plans to reduce or fight cardiovascular diseases.
Aerobic exercise is good for you....but there is a problem:
Bouchard and Timmons noticed a problem, however, and brought together a team to address it: although aerobic exercise can and does increase VO2 max in some people, exercise doesn’t work equally for everyone. Some people who exercise experience little or no increased VO2 max. Aerobic exercise for those people may not help ward off heart disease and other potential ailments.
According to Bouchard, executive director of PBRC, using lifestyle changes to prevent common diseases - such as starting an exercise routine - would be better targeted if healthcare specialists knew ahead of time who would benefit. Bouchard and his colleagues have now moved closer to that goal. They have just published a comprehensive look at a group of genes that modulate the increase in VO2 max due to aerobic exercise.
“We can now take a biological sample from a person and tell if he or she is likely to increase VO2 max through aerobic exercise training,” Timmons said, “This new approach will help physicians personalise exercise programs to reduce or fight cardiovascular diseases. However, if a patient is not likely to benefit much from aerobic exercise, the physician could turn to other type of exercise or alternative therapies. This would be one of the first examples of personalized, genomic-based medicine.”
The Telegraph also reported this and Barry Groves pointed it out