It is well recognized that physical activity and strength training correlate with improved life expectancy in later life. In animal studies, it can be shown that exercise causes increased healthy life spans. The study here reinforces that mountain of data. It is also interesting for adding to the evidence to show that the greatest benefits for increased activity occur in people who were sedentary. The dose response curve for exercise provides the greatest benefits when moving between no exercise and a sensible level of regular moderate exercise. Above that, there are still further benefits to be obtained, but gains in life expectancy taper off. To turn that around, being sedentary is very harmful to health over the long term. Try not to be sedentary.
Physical activity is associated with lower risks of all cause mortality, cardiovascular disease, and certain cancers. However, much of the epidemiology arises from observational studies assessing physical activity at a single point in time, and associations with subsequent mortality and chronic disease outcomes. As physical activity behaviours are complex and vary over the life course, assessing within-person trajectories of physical activity over time would better characterise the association between physical activity and mortality.
Participants in this study were 14,599 men and women (aged 40 to 79) from the European Prospective Investigation into Cancer and Nutrition. Physical activity energy expenditure (PAEE) was derived from questionnaires, and calibrated against combined movement and heart rate monitoring. Long term increases in PAEE were inversely associated with mortality, independent of baseline PAEE. For each 1 kJ/kg/day per year increase in PAEE (equivalent to a trajectory of being inactive at baseline and gradually, over five years, meeting the World Health Organization minimum physical activity guidelines of 150 minutes/week of moderate-intensity physical activity), hazard ratios were: 0.76 for all cause mortality, 0.71 for cardiovascular disease mortality, and 0.89 for cancer mortality, adjusted for baseline PAEE, and established risk factors.
In conclusion, we showed that middle aged and older adults, including those with cardiovascular disease and cancer, stand to gain substantial longevity benefits by becoming more physically active, irrespective of past physical activity levels and established risk factors - including overall diet quality, body mass index, blood pressure, triglycerides, and cholesterol. Maintaining or increasing physical activity levels from a baseline equivalent to meeting the minimum public health recommendations has the greatest population health impact, with these trajectories being responsible for preventing nearly one in two deaths associated with physical inactivity. In addition to shifting the population towards meeting the minimum physical activity recommendations, public health efforts should also focus on the maintenance of physical activity levels, specifically preventing declines over mid to late life.