Better cardiorespiratory fitness is associated with lower mortality risk at all ages

Extreme fitness did not increase mortality in a large observational study. Studies link cardiorespiratory fitness to lower all-cause mortality. Some evidence suggests excessive physical activity is harmful, especially in older adults. To better understand the association between cardiorespiratory fitness and mortality risk across the age spectrum, investigators examined deaths in ≈750,000 U.S. veterans aged 30 to 95 years (94% men), including ≈111,000 in their 70s and 27,000 in their 80s, who had undergone a standardised exercise treadmill test. Cardiorespiratory fitness was assessed using peak METs (Metabolic Equivalent) achieved.

During a median follow-up of 10.2 years, there was an inverse association between cardiorespiratory fitness and mortality across age, sex, and race strata. The highest mortality risk was seen in the least fit individuals (20th percentile for peak MET [≈5]), who had a fourfold higher risk compared with the fittest individuals (98th percentile for peak MET [≈14]), who had the lowest mortality risk, regardless of gender.

The investigators did not find evidence of increased mortality risk with extremely high cardiorespiratory fitness, even in the oldest individuals.

Source: Journal Watch