LAUSR

The dose–response relationship between physical activity and health is of great interest to policy makers, clinicians and individuals. Several recent analyses of large-scale population data have advanced our understanding, particularly in teasing apart minimal and optimal physical activity dosage. For example, if we focus on ‘minimal’ dose, 15 min a day of moderate-intensity exercise lowered mortality in a sample of more than 400 000 adults from Taiwan.1 A recent meta-analysis of nine cohort studies revealed that undertaking some moderate to vigorous physical activity (MVPA) but less than the guidelines was associated with 22% reduction in mortality risk in older adults.2 For those fortunate to be able to be performing the ‘optimal’ levels of physical activity, an analysis of more than 600 000 adults of all ages from the USA and Europe showed that a nearly optimal threshold for longevity occurred at three to five times the physical activity recommendation (39% reduction in all-cause mortality). Note that the additional benefit over and above doses corresponding to one to two multiples of the physical activity guideline (31% reduction in all-cause mortality) was rather modest in general.3 In a new study4 using a …