Skip Navigation LinksHome > August 2009 - Volume 41 - Issue 8 > Characterizing Differences in Mortality at the Low End of th...
Medicine & Science in Sports & Exercise:
doi: 10.1249/MSS.0b013e31819ca063
Basic Sciences

Characterizing Differences in Mortality at the Low End of the Fitness Spectrum


Collapse Box


Purpose: A graded nonlinear relationship exists between fitness and mortality with the most remarkable difference in mortality rates observed between the least-fit (first, Q1) and the next-least-fit (second, Q2) quintile of fitness. The purpose of this study was to compare clinical characteristics, exercise test responses, and physical activity patterns in Q1 versus Q2 in apparently healthy individuals.

Methods: A total of 4384 subjects referred for clinical treadmill testing from 1986 to 2006 were followed for a mean ± SD period of 8.7 ± 5.3 yr. All subjects had normal exercise ECG responses and no history of cardiovascular disease. Subjects were classified into quintiles of exercise capacity measured in METs. Clinical characteristics, physical activity patterns, and treadmill test results were compared between the first two quintiles (Q1: METs <5.9 (n = 693); Q2: METs 6.0-7.9 (n = 842)).

Results: Small differences in age (64 ± 11 vs 60 ± 10 yr, P < 0.001), use of antihypertensive medications, prevalence of diabetes (21% vs 16%, P = 0.02), and dyslipidemia (43% vs 49%, P = 0.04) were observed between Q1 and Q2. When the Cox proportional hazards model was adjusted for age and other clinical characteristics, the relative risk of mortality remained almost two times greater in Q1 versus Q2 (cardiovascular mortality: HR: 4.01 vs 2.01, P < 0.001; reference group: fittest subjects (Q5)). In a subset of 802 subjects, recent recreational physical activity was significantly lower in Q1 versus Q2.

Conclusions: Reduced physical activity patterns rather than differences in clinical characteristics contribute to the striking difference in mortality rates between the least-fit and the next-least-fit quintile of fitness in healthy individuals.

© 2009 American College of Sports Medicine


Article Tools


Article Level Metrics

Search for Similar Articles
You may search for similar articles that contain these same keywords or you may modify the keyword list to augment your search.

Connect With Us