The effects of a graduated aerobic exercise programme on cardiovascular disease risk factors in the NHS workplace: a randomised controlled trial

Abstract

Background

Sufficient levels of physical activity provide cardio-protective benefit. However within developed society sedentary work and inflexible working hours promotes physical inactivity. Consequently to ensure a healthy workforce there is a requirement for exercise strategies adaptable to occupational time constraint. This study examined the effect of a 12 week aerobic exercise training intervention programme implemented during working hours on the cardiovascular profile of a sedentary hospital workforce.

Methods

Twenty healthy, sedentary full-time staff members of the North West London Hospital Trust cytology unit were randomly assigned to an exercise (n = 12; mean ± SD age 41 ± 8 years, body mass 69 ± 12 kg) or control (n = 8; mean ± SD age 42 ± 8 years, body mass 69 ± 12 kg) group. The exercise group was prescribed a progressive aerobic exercise-training programme to be performed 4 times a week for 8 weeks (initial intensity 65% peak oxygen consumption (VO _{2 peak})) and to be conducted without further advice for another 4 weeks. The control was instructed to maintain their current physical activity level. Oxygen economy at 2 minutes (2minVO ₂), 4 minutes (4minVO ₂), VO _{2 peak}, systolic blood pressure (SBP), diastolic blood pressure (DBP), BMI, C-reactive protein (CRP), fasting glucose (GLU) and total cholesterol (TC) were determined in both groups pre-intervention and at 4 week intervals. Both groups completed a weekly Leisure Time Questionnaire to quantify additional exercise load.

Results

The exercise group demonstrated an increase from baseline for VO _{2 peak} at week 4 (5.8 ± 6.3 %) and 8 (5.0 ± 8.7 %) (P < 0.05). 2minVO ₂ was reduced from baseline at week 4 (-10.2 ± 10.3 %), 8 (-16.8 ± 10.6 %) and 12 (-15.1 ± 8.7 %), and 4minVO ₂ at week 8 (-10.7 ± 7.9 %) and 12 (-6.8 ± 9.2) (P < 0.05). There was also a reduction from baseline in CRP at week 4 (-0.4 ± 0.6 mg·L ^-1) and 8 (-0.9 ± 0.8 mg·L ^-1) (P < 0.05). The control group showed no such improvements.

Conclusion

This is the first objectively monitored RCT to show that moderate exercise can be successfully incorporated into working hours, to significantly improve physical capacity and cardiovascular health.