Physical activity in a sample of New Zealand professional employees
Physical activity is now a key strategy for preventing or minimising numerous chronic diseases. Worksites are an ideal location to promote regular physical activity. For workers, a large portion of waking hours is spent at work where numerous opportunities exist to accumulate physical activity. Consequently, the aims of this thesis were to: 1) systematically review worksite physical activity literature, especially in the New Zealand context; 2) identify the contribution of worksite activity to total activity levels, and the correlates contributing to physical activity levels for professional occupations; and 3) objectively measure physical activity changes with point of decision prompt visibility in professional worksites. Accordingly the thesis incorporated one systematic review and two separate studies.Effect sizes calculated in an analysis of previous worksite physical activity health promotion studies show inconclusive evidence for increased employee retention and job satisfaction, and no evidence of reduced absenteeism or productivity increases. A major criticism of worksite research is that many unvalidated and unreliable designs are used, limiting study efficacy. Research initiatives need to identify the determinants of physical activity for different occupations, ethnicities, and gender in New Zealand worksites.Study 1 (N=56) consisted of participants wearing two pedometers over a three-day block, and subsequently completing a Three-Day Physical Activity Recall (3DPAR). A moderate, positive Spearman correlation (r=0.28) existed between the METs (3DPAR) and total pedometer values. Contributions of (mean + SD)worksite (14 283 +4761), non-work (12 516 +4 172), and total (26 798 +8 933) pedometer values were analysed. The sample was divided into tertiles according to total step counts. The high activity group (HAG) achieved more physical activity outside the workday (56%) when compared to the lowest activity group (LAG) (29%). Physical activity correlates were identified using binary logistic regression and simple correlation analyses. Relationships between physical activity and active transport, manual work, sport and exercise, and individual exercise were shown.Study 2 evaluated the National Heart Foundation (NHF) point of decision prompts for increasing physical activity levels in professional worksites. Forty-six participants (27 men and 19 women) wore two pedometers for three days, over four occasions to monitor changes in physical activity. The study was a crossover design with Worksite 1 receiving the treatment for three weeks, followed by a six-week wash out period, then a three-week control. Worksite 2 was given the control prior to the treatment period. Results indicate that the NHF point of decision prompts were ineffective at increasing objectively measured work and total physical activity levels, showing trivial positive (0.04) to moderate negative Cohen effect sizes (-0.79). When point of decision prompts were visible in the worksites overall mean step counts decreased. On the basis of these findings, the NHF's point of decision prompts had no effect, or were potentially detrimental to physical activity.Nevertheless, both studies were limited by some traditional worksite design problems, including low participation and sample contamination. However, by incorporating an objective measure of physical activity (pedometers) and a robust study design, these findings are the first objective measures of worksite physical activity, and the effects of point of decision prompts in a confined sample.