Fitness versus physical activity patterns in predicting mortality in men

Area of Science:

• Cardiology
• Preventive Medicine
• Exercise Physiology

Background:

• All-cause mortality risk is influenced by multiple factors.
• Differentiating the predictive power of fitness level versus physical activity patterns is crucial for public health.
• Established risk factors like smoking and diabetes are known mortality predictors.

Purpose of the Study:

• To compare the independent contributions of cardiorespiratory fitness and physical activity patterns to all-cause mortality.
• To determine which factor, fitness level or activity pattern, is a stronger predictor of mortality.
• To assess the predictive value of exercise capacity and activity patterns against traditional risk factors.

Main Methods:

• Analysis of 6,213 men referred for exercise testing (1987-2000).
• Assessment of adulthood physical activity patterns in 842 participants.
• Multivariate analysis incorporating clinical data, exercise test results, and activity patterns to predict all-cause mortality over a mean follow-up of 5.5 years.

Main Results:

• Exercise capacity was a stronger predictor of mortality than physical activity patterns (HR=0.56).
• In multivariate analysis, both exercise capacity (HR per quartile=0.62) and energy expenditure from recreational activity (HR per quartile=0.72) significantly predicted mortality.
• Both fitness and activity were stronger predictors than smoking, hypertension, obesity, and diabetes. A 1000-kcal/wk increase in activity conferred a 20% mortality benefit, similar to a 1 metabolic equivalent increase in fitness.

Conclusions:

• Exercise capacity, assessed via exercise testing, is a superior predictor of all-cause mortality compared to other clinical and exercise test variables.
• Energy expenditure from weekly physical activity also significantly predicts mortality.
• Both fitness level and physical activity are critical, independently modifiable factors for reducing mortality risk.