Exercise intensity not linked to risk of early death in older adults

Squeezing in time to sweat is a struggle, so we don't blame you for wondering how much is just enough The rule of thumb is 75-150 minutes of moderate to intense aerobic exercise per week in addition to 2 sessions of total-body strength training per week Life-lengthening and heart-boosting benefits manifest halfway through the recommended workout dose You can divide your cardio time into five 30-minute sessions or three 25-minute HIIT workouts Or sneak more movement into your everyday life to count toward

Physical activity is important for people of all ages to improve health, and data from observational studies show that early death is significantly reduced in physically active compared with inactive individuals.

High levels of physical activity of any intensity, whether washing dishes or jogging, can lower the risk of an early death for middle-aged and older people, studies suggest.

However, clinical trial evidence on a potential direct relation between current advice on physical activity levels and longevity is lacking.

To remedy that, an international research team set out to evaluate what effect five years of supervised exercise training had on the death rate of adults 70-77 years old, compared with recommendations for physical activity, which are much less.

The trial study involved 790 women and 777 men living in Trondheim, Norway, with an average age of 73 years. Of those, 87.5% reported overall good health, and 80% reported a medium or high level of physical activity at the start of the trial.

Of the 1,567 participants, 400 were assigned to two weekly sessions of high intensity interval training (HIIT), 387 were assigned to moderate intensity continuous training (MICT), and 780 to follow the Norwegian guidelines for physical activity (control group), all for five years.

After five years, the overall mortality rate was 4.6%, or 72 participants, the researchers wrote in a study pubished this week in the journal The BMJ.

The researchers found no difference in all cause mortality between the control group (4.7%, 37 participants) and combined HIIT and MICT group (4.5%, 35 participants).

They also found no differences in cardiovascular disease or cancer between the control group and the combined training groups.

For example, the total proportion of participants with cardiovascular disease after five years was 15.6%, with 16% (125 participants) in the control group, 15% (58 participants) in the MICT group and 15.3% (61 participants) in the HIIT group.

The trial was not without limitations, the researchers noted. For example, “highly active participants in the control group could have hampered finding differences between groups, and many participants were healthier than expected at the start of the study, which may have limited the potential to increase activity levels further," they wrote.

The large number of participants and the long monitoring period were two of its strengths.

“This study suggests that combined MICT and HIIT has no effect on all cause mortality compared with recommended physical activity levels,” the researchers wrote.