Level of Physical Activity at the Age of 65 Predicts Successful Aging Seven Years Later: The PROOF Study

Background: Physical activity has a pleiotropic effect and is a significant factor in successful aging. This study aims to quantify the relationship between the physical activity of a 65-year-old cohort and the level of life satisfaction and self-rated health 7 years later. Methods: A total of 988 questionnaires were sent by mail to a representative sample of healthy pensioners. Life satisfaction and health status were estimated on two visual analogical scales in answer to the following questions: (1) How would you estimate your state of health? and (2) Are you generally satisfied with your life? The level of physical activity was estimated using a questionnaire which enabled us to calculate: (1) Daily energy expenditure (DEE), (2) physical activity energy expenditure (PAEE), (3) daily energy expenditure higher than 5 metabolic equivalents (METs) (DEQisa), (4) Activity index (PAEE/DEE), (5) VO2 peak. Results: In all, 686 responses were validated. The average age was 72.9 +/- 1.2 years old with 59.5% of women (n = 408). Amongst the sample, 98.8% (n = 676) lived in their own homes and 25.2% (n = 172) lived alone. Mean DEE was 10.365 +/- 1.964 kJ/24 h, mean PAEE was 4.479 +/- 1.170 kJ/24 h, mean activity index was 0.42 +/- 0.05, and mean estimated oxygen uptake (VO2) peak was 22.5 +/- 1.6 mL/min per kg. Activity index and VO2 peak were the variables most significantly correlated with self-rated health (p = 0.0032 and p = 0.0011, respectively) and life satisfaction (p = 0.0117 and p = 0.0053). Conclusions: Energy spent in activity and VO2 peak estimated from DEE, measured at the age of 65, appear to be strong predictors of well-being 7 years later.