Step-wise to better health
Although the first version of a step-counter was designed by Leonardo da Vinci in the 15th century, it was not until 20 years ago that we started using it in North America. Step-counters, called “pedometers” have a pendulum mechanism that counts steps taken. Simple, accurate pedometers cost about $25, making them among the least expensive adjuncts to physical activity and therefore accessible to most people. How can a simple, low-cost device actually improve the health and fitness of our population, which is increasingly sedentary and overweight?
Research using pedometers generally falls into two types: surveillance and intervention. Surveillance research only monitors the walking activity of the persons, including children and the elderly. These types of studies are only interested in the pedometer as a step-counter. On the other hand, intervention research makes use of other properties of pedometers that influence the wearer’s behaviour. In that case, pedometers are not just monitors; they truly reflect your minute-to-minute activity throughout the day. If you have barely moved from your desk all morning, they let you know it, thereby providing valuable feedback. Furthermore, pedometers count all your steps, not just the ones taken during “exercise”. Knowing how low your activity is can be really motivating to do more, especially in the context of a structured intervention.
In our research, we hypothesized that people working in sedentary jobs would walk less; irrespective of any “exercise” they might engage in outside their working area. This would correlate with some health-related measures like body mass index (BMI). We monitored the physical activity of workers with sedentary jobs, mainly people doing desk-bound work, like data entry or keyboarding. The least active people had the highest BMI and waist circumference (two indirect measures of body fat) and the highest blood pressure. Half the people in the study considered their jobs to be highly sedentary and these individuals were the less active in terms of steps per day, showing that work-related activity is a big contributor to total activity. We then rationalized that a workplace-based intervention could work well to help sedentary workers become more active, particularly with the help of pedometers for monitoring and feedback.
The intervention was based on the First Step Program, which was originally developed for type 2 diabetes patients1. The idea was to see if such an intervention would be useful in the general population, and whether those who adopted it would experience improvements in measured health indices. In the intervention, participants were instructed in the use of the pedometer and encouraged to set goals based on an initial determination of their usual steps per day. Each day they compared the steps per day they achieved with their goal, using the pedometer to provide monitoring, feedback and improve motivation. After the study, which lasted 3 months, we found that the average steps per day increased from about 7,000 to more than 10,400 – an increase of nearly 50% that equated to about 30 minutes more of physical activity each day! The other results included small decreases in body mass index, waist circumference and resting heart rate (which are indirect measures of fitness)2.
Can a simple, low-cost device actually improve the health and fitness of our population, which is increasingly sedentary and overweight? According to 26 studies where more than 2,500 people had to use a pedometer during 4 to 26 weeks, the use of a pedometer can help increasing the number of steps of about 25% and reach a significant decrease in BMI3. Since this involves devoting 20-30 minutes or more per day to being physically active, it is a good way to help people achieve the recommendations laid down by Canada’s Physical Activity Guide to Healthy, Active Living. Furthermore, since the majority of people cite walking as a preferred activity, they can find in the use of a pedometer an invaluable “guilty conscience” that inspires them to increase their walking activities.
However, pedometers are not without some limitations. Indeed, the First Step model for the intervention may not appeal to everyone. Some participants to our study dropped out early from the intervention (around 25%) or never increased their steps. This suggests that other models may be needed to reach a wider population. Also of notice was the fact that some participants increased their steps temporarily but quickly reverted to old habits when the intervention was finished. This raises questions about the capacity of pedometers alone to really instill permanent changes of attitudes towards physical activities. Additional motivations or a longer period of intervention might be necessary to maintain the benefits gained through the First Step model intervention. Further research should explore these avenues.
|Author :||Catherine B. Chan, Ph.D.
Department of Physiology and Agricultural, Food and Nutritional Sciences
University of Alberta
Tudor-Locke, C., et al., Controlled outcome evaluation of the First Step Program: a daily physical activity intervention for individuals with type II diabetes. Int J Obes Relat Metab Disord, 2004. 28: p. 113 – 119.
Chan, C., D. Ryan, and C. Tudor-Locke, Health benefits of a pedometer-based physical activity intervention in sedentary workers. Prev Med, 2004. 39: p. 1215 – 1222.
Bravata, D.M., et al., Using pedometers to increase physical activity and improve health. A systematic review. J Am Med Assoc, 2007. 298(19): p. 2296-2304.