In 2008 Americans were happy to have Physical Activity Guidelines. According to them they were recommended a minimum of 75 vigorous-intensity or 150 moderate-intensity minutes per week of aerobic activity for substantial health benefit and suggested additional benefits by doing more than double this amount.
So there was a precaution that people engaging in 10 times the recommended minimum are at a higher mortality risk.
Nevertheless, the broad study published in JAMA Internal Medicine scrutinized the relationship between physical activity and mortality rates.
The research aimed to quantify the dose-response association between leisure-time physical activity and mortality and define the upper limit of benefit or harm associated with increased levels of physical activity.
In short, those hardcore bodybuilders who live at the gym decrease their mortality risk nearly the same amount as those who engage in the minimum recommendation.
The data pooled six studies covering 661,000 people exposed to no leisure-time physical activity to those participating in the vigorous physical activity. It then compared 14 years of death records for the group.
Compared to individuals reporting no leisure-time activity, the report found:
- 20% lower mortality risk for those performing less than the recommended minimum of 7.5 metabolic-equivalent hours per week,
- 31% lower mortality risk at one to two times the recommended minimum,
- 37% lower mortality risk at two to three times the recommended minimum,
- 39% lower mortality risk at three to five times the recommended minimum (benefit threshold).
Regarding mortality, health care professionals should encourage inactive adults to perform the leisure-time physical activity and do not need to discourage adults who already participate in high-activity levels.