Are cardiorespiratory fitness and walking performance associated with self-reported quality of life and work ability?

In Finland, testing cardiorespiratory fitness (VO2max) is popular in health promotion programs and work ability evaluations. The most common instruments used for this purpose are the submaximal cycle ergometer test, and the 2-km walking test. However, limited data exist on the associations between VO2max and wellbeing in working age adults. The aim of the study was to evaluate how the measured (cycle ergometer) and the estimated (walking test) VO2max and walking performance are associated with health-related quality of life and work ability.

The subjects were 104 middle-aged men workers (45-55 years old), mostly from the construction and manufacturing industries. VO2max was directly measured by a maximal exercise test on a cycle ergometer. The 2-km walking test parameters were the walking time, predicted VO2max, and fitness index. Health-related quality of life was assessed with the RAND-36 questionnaire which was further divided into physical dimensions (P-RAND-36) and mental dimensions (M-RAND-36). Perceived work ability was assessed with the work ability index (WAI) in a subgroup of 51 subjects.

The 2-km walking test parameters significantly predicted the score on P-RAND-36 (r2=0.18, p=0.001), and correlated significantly with WAI. The directly measured VO2max was not associated with P-RAND-36, M-RAND-36 or WAI.

The inexpensive 2-km walking test may be more useful when evaluating the quality of life and work ability, compared to the more expensive direct measurement of one's cardiorespiratory fitness in a laboratory.