New research may explain why some people get more from exercise than others

While everyone can benefit from exercise, the mechanistic links between fitness and overall health are not fully understood, nor are the reasons why the same exercise can have different effects on different people. Now a study published in Nature’s metabolism led by researchers at Beth Israel Deaconess Medical Center (BIDMC) provides information related to these unanswered questions. The results could be useful in determining specific types of exercise most likely to benefit a particular individual and in identifying new therapeutic targets for metabolism-related diseases.

“Although the groups as a whole benefit exercise, the variability in responses between two individuals suffering from the same exercise regimen is truly staggering. For example, some may experience improved endurance, while others will see improved blood sugar levels“said the corresponding lead author, Robert E. Gerszten, MD, head of BIDMC’s Division of Cardiovascular Medicine.” To date, no aspect of an individual’s baseline clinical profile allows us to predict in advance who is most likely to achieve significant cardiorespiratory fitness. benefit from physical training “.

To find out the details behind the effects of exercise on the body and how they may differ from person to person, the team, including first author Jeremy Robbins, MD, of BIDMC’s Division of Cardiovascular Medicine , measured blood levels of approximately 5,000 proteins in 650 sedentary adults before and after a 20-week resistance exercise program.

“We were especially interested in examining blood proteins to study the effects of exercise, as there is a growing body of evidence showing that exercise stimulates the secretion of chemicals into the circulation that can transmit their effects on distant organs, ”Robbins said.

A set of 147 proteins in the blood indicated an individual’s cardiorespiratory form, or VO2max, at the start of the study. Another set of 102 proteins indicated an individual’s change in VO2max after completing the exercise program.

“We identified proteins that emanate from bones, muscles, and blood vessels that are strongly related to cardiorespiratory fitness and have never been previously associated with exercise training responses,” said Gerszten, who is also a professor. of Medicine Herman Dana at Harvard Medical School and senior associate member of the Broad Institute of MIT and Harvard.

Robbins added: “Although previous studies have shown that a person’s level of fitness is unrelated to their response to exercise training, it was fascinating to see that there was minimal overlap between protein profiles of basal VO2max and their response to exercise training intervention “.

With this information, the research team developed a protein score that improved their ability to predict an individual’s training ability or change in VO2max. For example, the score identified individuals who were unable to significantly improve their cardiorespiratory form despite participating in the standardized exercise program. “Basal levels of various proteins predicted who would respond to the exercise training protocol much better than any of the factors established by our patients,” Gerszten said.

In a separate community study, despite being part of the same paper, the scientists found that some of these proteins were associated with a high risk of early death, highlighting the link between cardiorespiratory form and long-term health outcomes.

“We now have a detailed list of new blood compounds that inform more about our understanding of the biology of aptitude and adaptation to exercise, and predicting individual responses to a given exercise regimen, “Gerszten said.” While no pill is likely to recapture the diversity of exercise benefits, our study has helped create a roadmap to further explore possible interventions and provide a step in the individualization of exercise as a therapy. He noted that further research is needed to expand the results of the study to larger populations and refine the precise effects of the different proteins before and after exercise.