Here at CABI, we are fortunate that our offices are situated in the countryside, among fields and just a few minutes away from the River Thames. So on a sunny spring day like today, there is a mass exodus at lunchtimes as the CABI staff drag themselves away from their computers to get some fresh air and exercise. But if we want more than a screen break and to keep ourselves fit and healthy, just how far and fast do we need to walk?
Research published online this week gives a suitable target. According to a paper in the American Journal of Preventative Medicine, walking at a speed of at least 100 steps per minute for half an hour a day is a suitable figure for achieving moderate intensity activity.
Researchers at the San Diego State University based their conclusions on exercise tests given to 97 healthy adults who had an average age of 32. While being monitored for oxygen uptake during walking on a treadmill, 58 woman and 39 men completed four 6-minute sessions at different treadmill speeds between 65 and 110 meters per minute. All wore pedometers and their heart rates were recorded. Using 3 METs, or metabolic equivalents, as the minimum level of oxygen demand which approximates moderate exercise, participants were monitored to determine whether they had reached the moderate-exercise level at a given treadmill speed.
In general, men needed to walk at a pace of 92 to 102 steps per minute to achieve a moderately intense workout for their hearts. The range for women was between 91 and 115 steps per minute.
"Because health benefits can be achieved with bouts of exercise lasting at least 10 minutes, a useful starting point is to try to accumulate 1000 steps in 10 minutes, before building up to 3000 steps in 30 minutes," said Simon Marshall, lead researcher.
A pedometer was not useless, but should be used in conjunction with a wristwatch to work out how many steps were being taken. It is suggested that the use of a single and simple pedometer-based guideline that is easy both to remember and measure may be more effective in a health communication strategy than the promotion of multiple guidelines and, therefore, messages.”
Coincidentally, a circular walk I sometimes do at lunchtimes takes around half an hour at what seems (to me) to be a reasonably good pace. Does it takes 3000 steps? I've no idea – but maybe I'll try and get hold of a pedometer to find out!
The article is “Translating Physical Activity Recommendations into a Pedometer-Based Step Goal: 3000 Steps in 30 Minutes” by Simon J. Marshall, Susan S. Levy, Catrine E. Tudor-Locke, Fred W. Kolkhorst, Karen M. Wooten, Ming Ji, Caroline A. Macera, and Barbara E. Ainsworth. It appears in the American Journal of Preventive Medicine, Volume 36, Issue 5 (May 2009). The paper is currently freely available in PDF format through this link.