title: Work ability, physical activity, and cardiorespiratory fitness: 2-year results from Project Active.
abstract: 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 (kcal.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 was 44.2 +/- 4.0, and it 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.
authors.affiliation: Finnish Institute of Occupational Health, Helsinki, Finland.
authors.forename: J
authors.initials: J
authors.lastname: Smolander
authors.forename: S N
authors.initials: SN
authors.lastname: Blair
authors.forename: H W
authors.initials: HW
authors.lastname: Kohl
mesh_terms: D000328:Adult; D001835:Body Weight; D003376:Counseling; D004734:Energy Metabolism; D015444:Exercise; D005260:Female; D006293:Health Promotion / Q000379:methods*; D006801:Humans; D008019:Life Style; D008297:Male; D008875:Middle Aged; D010101:Oxygen Consumption; D010809:Physical Fitness; D014938:Work Capacity Evaluation