Dose of jogging and long-term mortality: the Copenhagen City Heart Study.
Level 3 - non-randomized controlled study
Prospective non-randomized cohort study
PubMed 25660917 · doi:10.1016/j.jacc.2014.11.023
What was done
The Copenhagen City Heart Study prospectively followed 1,098 healthy joggers and 3,950 healthy nonjoggers starting in 2001. Cox proportional hazards regression analysis with age as the underlying time scale and delayed entry was performed to evaluate the relationship between all-cause mortality and jogging pace, quantity, frequency, and overall dose category (light, moderate, and strenuous).
What was found
Compared with sedentary nonjoggers, 1 to 2.4 hours of jogging per week was associated with the lowest mortality (multivariable HR: 0.29; 95% CI: 0.11 to 0.80). Jogging 2 to 3 times per week (HR: 0.32; 95% CI: 0.15 to 0.69) or ≤1 time per week (HR: 0.29; 95% CI: 0.12 to 0.72) showed the lowest mortality by frequency. Slow pace (HR: 0.51; 95% CI: 0.24 to 1.10) and average pace (HR: 0.38; 95% CI: 0.22 to 0.66) had lower hazard ratios. By dose tier, light joggers had the lowest mortality (HR: 0.22; 95% CI: 0.10 to 0.47), followed by moderate joggers (HR: 0.66; 95% CI: 0.32 to 1.38) and strenuous joggers (HR: 1.97; 95% CI: 0.48 to 8.14).
Why it matters
The study suggests a U-shaped association between exercise dose and longevity, indicating that modest amounts of jogging confer optimal survival benefits while strenuous jogging may not provide additional protection.
Limits
The observational design cannot establish causality or rule out residual confounding. The strenuous jogger group had very wide confidence intervals (0.48 to 8.14) indicating marked statistical imprecision. Specific causes of death, changes in jogging habits over time, and potential unmeasured health differences were not detailed in the abstract.
Cited by
- supports The Copenhagen City Heart Study reported increased mortality among high-volume runners based on only two deaths in that group.