High-intensity interval training (HIIT) and other types of exercise aimed at “maximum effort to achieve muscle fatigue and maximum oxygen use in a quick burst of exercise” have taken the fitness world by storm. However, how these programs apply to older adults is still not fully understood. A recent study led by Dr. David Hupin, of the Department of Clinical and Exercise Physiology at the University Hospital of St-Etienne-Lyon, has found that 75 minutes of moderate to vigorous physical activity each week is “a reasonable target dose” for lowering the risk for death among people past their 60s.

"Based on these results, we believe that the target for physical activity in the current recommendations might be too high for older adults and may discourage some of them,” the research team said in a statement. “The fact that any effort will be worthwhile may help convince those 60 percent of participants over 60 years of age, who do not practice any regular physical activity, to become active."

Hupin and his colleagues gathered data from nine studies published up to February 2015. Each study examined the risk for death according to the amount of weekly physical activity people in their 60s and up took part in. The amount of physical activity was measured in Metabolic Equivalent of Task (MET) minutes – the amount of energy (calories) expended each minute of exercise. The Physical Activity Guidelines for Americans recommends between 500 and 1,000 MET minutes each week.

Pooled analysis from a total of 122,417 participants, 18,122 who died over the course of 10 years from the start of their study, revealed that even 500 weekly MET minutes (equivalent to 150 minutes of moderate to vigorous physical activity) was associated with a 22 percent lower risk for death compared to physical inactivity. Participants who took in the recommended amount of MET minutes lowered their risk for death by 28 percent and those who participated in over 1,000 MET minutes by 35 percent.

When it came to the recommended daily amount of MET minutes, the research team argued that current standards are often too difficult for most older adults. In fact, findings from the study showed that 250 MET minutes (equivalent to 75 minutes of moderate to vigorous physical activity per week or 15 minutes of exercise a day) was associated with various health benefits, including a lower risk of dying from heart disease, stroke, and all cause mortality. Those first 15 minutes of exercise were considered to be the most important.

A similar study that was also led by Hupin was aimed at determining the amount of exercise seniors need to reduce their risk for death. Results showed that even seniors who participate in very low levels of physical activity were still 51 percent less likely to die. The researchers even settled on a dose-dependent outcome: The more exercise a person got, the lower their risk of death over the trial period.

Source: Hupin D, et al. Even a low dose of moderate to vigorous physical activity reduces mortality by 22% in adults aged - 60 years: a systematic review and meta-analysis. British Journal of Sports Medicine. 2015.