“It was like a symphony,” says Michael Snyder, the chair of the genetics department at Stanford University and senior author of the study. “First you have the brass section coming in, then the strings, then all the sections joining in.”
This study is suggested to be the most comprehensive catalog to date of the molecular changes that occur during and after exercise that highlights how consequential activity/inactivity may be for the human body and health.
Different people’s blood follows different orchestrations; those showing signs of insulin resistance for example tended to show smaller increases in some of the molecules related to healthy blood sugar control and higher increases in molecules involved in inflammation, suggesting that they may be somewhat resistant to the general beneficial effects of exercise. Additionally, depending on the individual’s current aerobic fitness levels of other molecules ranged considerably.
Overall the researchers were surprised by their findings regarding what they were observing in the changes in molecular profiles after exercise: “I had thought, it’s only about nine minutes of exercise, how much is going to change? A lot, as it turns out.” said Dr. Snyder.
However, this study was not without its limitations such as being a small study that only included participants over the age of 40, and it only looked at a single session of aerobic exercise, as such this study can’t tell us anything about the longer term molecular effects of continued training or of how the changes in molecular levels may subsequently alter health.
The research team will be conducting follow up studies with more participants and sustained exercise routines, hoping to establish whether certain molecular responses to exercise may be able to distinguish those who might benefit from emphasizing resistance exercises over endurance training, and whether specific molecular profiles can indicate who has higher/lower aerobic endurance. Such answers may provide information that could allow physicians and researchers alike to check for fitness with a blood sample rather than treadmill stress testing.