Wednesday December 17 2008
“Employees who can exercise at work are more productive, happy, efficient and calm,” reported BBC News. It said that a study of 200 people found that on the days when staff used the gym, they felt re-energised, having improved their concentration and problem-solving abilities, and calmer.
This study has a number of limitations, including the facts that the employees rated their own work performance, and that only regular exercisers were included. Although this study does not provide conclusive evidence about the effects of exercising at work on work performance, getting enough exercise is clearly important for health, and is known to have a positive effect on mood. Workplaces that encourage a healthy lifestyle among their employees may well increase productivity, but further research will be needed to quantify any benefits.
Where did the story come from?
Dr JC Coulson and colleagues from the University of Bristol and Leeds Metropolitan University carried out this research. No sources of funding were reported for the study. It was published in the peer-reviewed International Journal of Workplace Health Management.
What kind of scientific study was this?
The study had two parts: a randomised crossover trial and a focus group analysis of themes. The researchers looked at the effects of exercise on self-reported mood and work performance.
The researchers selected three workplaces in south-west England that had onsite exercise facilities, a supportive attitude to exercising at work, over 250 employees, and where the staff were largely engaged in sedentary work. From these companies, a total of 201 employees who exercised regularly at work volunteered for the study.
The volunteers were sent two mood questionnaires, one to be filled out on a day on which they exercised, and one on a non-exercise day. The order in which the employees were asked to fill out the questionnaires (i.e. on an exercise day or non-exercise day first) was randomly chosen for each employee. On their exercise day, the employees recorded how long they exercised for and their mood before and after exercise. On the non-exercise day, they recorded their mood at the start and end of the day.
At the end of both days, the employees completed work performance questionnaires, with 10 validated (tried and tested) items and five non-validated items. These items included their ability to manage “time demands, mental-interpersonal demands and output demands”. The employees also reported how sedentary their job was, how heavy their workload was on both days, and whether there was anything unusual about either of the days.
The researchers also held focus groups to ask about work performance-related topics. These were recorded by an independent observer with the general discussion themes analysed in a qualitative, or descriptive, way.
What were the results of the study?
About two-thirds of participants were women, and the average age was 38 years. Most (72%) took part in cardiovascular exercise (such as treadmills and exercise classes), with 12% taking part in weight training, and 16% in games or team sports. When asked about their physical activity levels, 80% reported doing “moderate to vigorous” physical activity, and the remainder reported it as “very hard”.
There was no difference in workload on the exercise and non-exercise days. Positive mood, fatigue and tranquillity before exercise/at the start of the day was similar on exercise and non-exercise days, but negative mood was greater on the exercise day. All four of these aspects of mood improved after exercise. Tranquility reduced from the start to the end of the day on the non-exercise day but all other aspects of mood remained the same.
Self-rated ability to manage time demands, mental-interpersonal demands and output demands showed small but statistically significant improvements on the exercise days compared to non-exercise days. If mood was adjusted for (taken into account), then only the difference in mental-interpersonal demands remained significant. Non-validated measures of work performance were also higher on the exercise day than non-exercise day. In particular, participants felt “more motivated/energised to work” on the exercise day.
In the focus groups, the themes reported by participants included both positive effects of exercise, such as better concentration and problem solving, as wel as negative: some also felt guilty about being away from their desks, and perceived that colleagues judged them negatively for their absence.
What interpretations did the researchers draw from these results?
The researchers concluded that “workday exercise can improve white-collar workers' mood and self-reported performance”. They also say there are “clear implications not only for employee wellbeing, but also for competitive advantage and motivation by increasing opportunities for exercising at work”.
What does the NHS Knowledge Service make of this study?
This was a relatively small study, which looked at the self-reported effects of exercise during a working day on mood and work performance. The study has a number of limitations to consider:
- The study only collected data on two days. Extending the study over a longer period of time would increase the reliability of results.
- The employees rated their own work performance. If they knew or guessed the aim of the study then how they reported their performance may have been affected. If the researchers had also used objective measures of performance, they could have determined if this was the case.
- The volunteers who took part in the study were already exercising regularly at work. Therefore, the results may not apply to different groups of people, such as those who exercise less regularly.
- On the non-exercise day, mood was recorded at the both start and end of the day, whereas on exercise days, mood was recorded before and after exercise. A person’s mood may change throughout the day, so as the data were collected at different times on exercise and non-exercise days, they may not be comparable.
- It was not clear on which day of the week the exercise and non-exercise days fell. If they tended to fall on different days of the week, this could affect the results of the study. For example, people might generally feel more productive towards the start of the week, and less so towards the end.
Although these results cannot be considered as conclusive, exercise is important for health and is known to have positive effects on mood. Workplaces that encourage a healthy lifestyle among their employees may well increase productivity.
Further research using objective measures of performance over a longer period of time are needed to quantify any benefits.