Comparative Relevance of Physical Fitness and Adiposity on Life Expectancy: A UK Biobank Observational Study.
Level 3 - non-randomized controlled study
Prospective cohort study
PubMed 31079962 · doi:10.1016/j.mayocp.2018.10.029
What was done
Researchers analyzed 474,919 participants from the prospective UK Biobank cohort (recruited March 13, 2006, to January 31, 2016). Baseline fitness measures included self-reported walking pace (slow, steady/average, brisk) and dynamometer-measured handgrip strength. Adiposity was evaluated using body mass index (BMI), waist circumference, and body-fat percentage. Life expectancy at age 45 years was estimated across fitness and adiposity strata over a median follow-up of 6.97 years.
What was found
Participants had a median baseline age of 58.2 years and a median BMI of 26.7 kg/m²; 12,823 deaths occurred during follow-up. Brisk walkers demonstrated longer life expectancies across all BMI categories, ranging from 86.7 to 87.8 years in women and 85.2 to 86.8 years in men. Slow walkers had shorter life expectancies across all BMI categories, with the lowest observed in slow walkers with BMI < 20 kg/m² (72.4 years in women, 64.8 years in men). Differences in life expectancy for handgrip strength were smaller and less consistent, especially in women. Similar patterns were observed when adiposity was defined by waist circumference or body-fat percentage.
Why it matters
This study indicates that walking pace, a simple surrogate marker of physical fitness, is strongly associated with survival independent of BMI, waist circumference, or body fat.
Limits
Walking pace was self-reported rather than objectively measured. The observational design cannot rule out residual confounding or reverse causation from subclinical disease. Follow-up was relatively short (median ~7 years) for modeling lifetime expectancy.
Cited by
- supports Research shows that people who walk faster have longer life expectancy.