Work ability, physical activity, and cardiorespiratory fitness: 2-year results from project active

An adequate level of physical activity may maintain or promote work ability in aging workers, Project Active is a randomized trial comparing a Lifestyle physical activity program with a Structured exercise program in sedentary but healthy adults aged 35 to 60 years. Subjects in both groups received 6 months of intensive intervention followed by 18 months of active follow-up. The total number of subjects was 235, from which 80 subjects participated in the work ability assessment. Primary outcome measures were energy expenditure (kg(-1) . day(-1)), cardiorespiratory fitness (peak oxygen uptake in ml . min(-1) . kg(-1)), and the Work Ability Index. At 6 months, daily energy expenditure had increased significantly over baseline (mean +/- SD, from 33.0 +/- 0.9 to 34.4 +/- 1.8 kcal . kg(-1) . day-(1)) and was maintained over baseline at 24 months (34.0 +/- 2.5 kcal . kg(-1) . day(-1)). The significant increase in energy expenditure was observed particularly in moderate levels of activity, The average percentage of body fat was significantly higher at baseline compared with 6 months and 24 months. Peak oxygen uptake increased from baseline significantly during the first 6 months (from 29.6 +/- 5.7 to 30.6 +/- 6.3 ml . min(-1) . kg(-1)) and decreased to the baseline level (29.1 +/- 5.5 ml . min(-1) . kg(-1)) at 24 months, At baseline the average Work Ability Index runs 44.2 +/- 4.0 and If remained unchanged at 6 months (44.4 +/- 3.9) and at 24 months (44.2 +/- 3.1). In conclusion, a 2-year physical activity intervention increased daily energy expenditure, reduced body fat, and maintained peak oxygen uptake in healthy, middle-aged, sedentary subjects. The average Work Ability Index score at baseline was excellent and did not change during the 2-year physical activity interventions.