Workout addicts spending hours upon hours per week at the gym can step away from the machines and take a deep breath.
They're safe.
A recent study showed no excessive mortality risk for active adults engaging in 10 times the recommended minimum amount of activity issued by the 2008 Physical Activity Guidelines (PAG), or 75 metabolic-equivalent hours per week.
The study also concluded the benefit ceiling for lowering mortality risk was 37.5 metabolic-equivalent hours of activity per week, or five times the minimum, and those people experienced a modest benefit in comparison to those doing the recommended minimum.
In short, those who engage in the minimum recommendation decrease their mortality risk nearly the same amount as those hardcore bodybuilders who live at the gym.
The broad study was published in JAMA Internal Medicine in June, and it scrutinized the relationship between physical activity and mortality rates. The data pooled six studies covering 661,000 people exposed to no leisure time physical activity to those participating in vigorous physical activity. It then compared 14 years of death records for the group.
The PAG recommended a minimum of 75 vigorous-intensity or 150 moderate-intensity minutes per week (7.5 metabolic-equivalent hours) of aerobic activity for substantial health benefit and suggested additional benefits by doing more than double that amount.
The study's goal was to define the upper limit of health benefit or harm associated with the increased levels of physical activity.
Compared to individuals reporting no leisure time activity, the report found:
- A 20 percent lower mortality risk for those performing less than the recommended minimum of 7.5 metabolic-equivalent hours per week,
- A 31 percent lower mortality risk at one to two times the recommended minimum,
- A 37 percent lower mortality risk at two to three times the recommended minimum,
- A 39 percent lower mortality risk at three to five times the recommended minimum (benefit threshold).
The study concluded that meeting the PAG minimum was associated with nearly the maximum longevity benefit.
The study encouraged health care professionals to encourage inactive adults to perform leisure time physical activity and said there was no need to discourage adults engaging in high activity levels.