By Gabe Sanders PhD, NSCA-CSCS
If you or someone you know has impaired glucose tolerance (IGT) or has been diagnosed with Type II diabetes, you should know that exercise is extremely important. Exercise can improve IGT, regardless of weight loss, and physical improvements can be noticed in a short amount of time. Some studies have shown that as little as one week of exercise can improve glucose tolerance and insulin action in your body. While the Center for Disease Control and Prevention suggests that individuals exercise or be physically active for 30 minutes a day on most if not all days of the week; more intense exercise can have a more favorable effect on glucose tolerance.
How intense should I exercise and what should I do?
There are several different exercises and durations that should be considered. The question is, “How intense should I exercise and what should I do?” Riding a bike or walking on a treadmill at 2.5 – 3.0 miles per hour for approximately fifty minutes at 70% of your max heart rate (MHR) seven days per week can improve glucose tolerance by as much as 35 percent. A good way to exercise at this intensity without having to use a scientific calculation would be to use the numbers 4-5 on the treadmill instead. More specifically, use a rating of perceived exertion (RPE) scale that ranges from 0-10, with zero being no exertion at all and ten being the most difficult exercise you have ever engaged in. If you feel like you are exerting yourself at a 4- 5 range on the RPE scale of 0-10; you should be exercising relatively hard and beginning to sweat.
Exercise at a higher intensity for 30-60 second bouts
Another type of exercise you could engage in to increase intensity would be to exercise on a bike at a higher intensity for 30-60 second bouts, followed by a minute of lower intensity exercise, and then repeated 6-10 times. A safe and effective RPE for higher intensity exercise should be in the 5-6 range on the 0-10 RPE scale. Caution should be taken when trying to exercise at higher intensities. A physician’s clearance is recommended prior to participating in this type of exercise.
Two exercise methods to potentially improve your glucose tolerance……
I. Moderate intensity training (MIT) for 50 minutes, five or more days per week
Treadmill
Begin walking on a treadmill. Set incline to 1%; gradually increase speed until moderately exerting yourself. Ask yourself, “On a scale of 0-10, how hard am I working?” If the answer is less than four, increase your speed or incline by 1% or increase your speed by 0.1 miles per hour until you achieve that magic RPE number of four.
Bicycle
Begin riding the bike, try to begin at an RPM (or pedal rate) of 50 RPMs. Ask yourself, “How hard am I working?” Increase either your pedal rate or bike resistance until you achieve your magic RPE number of four.
II. High-intensity training (HIT) for 30 seconds “On” and 60 seconds “Off”; repeat 6-10 times
Bicycle
Exercise on a bike, focus on your pedal rate. During the 30 seconds “On,” pedal at a rate that is significantly faster than 50 RPMs (for example, increase your RPMs to 60 or 70 if possible), then during the 60 seconds “Off” pedal at 40-50 RPMs. Now increase your RPMs again back up to a rate that is greater than 50 RPMs. Your magic RPE number should be a five or a six on the 0-10 scale. This workout will not take as long to complete but is equally as effective as a longer lower intensity exercise session.
*For more examples of other variations/exercises look under Multimedia-VDF Exercise Tips
**Consult with a physician and/or medical healthcare provider before starting any exercise regimen
Article’s Resources
Center for Disease Control. http://www.cdc.gov/physicalactivity/everyone/guidelines/index.html
Wright DC, Swan PD. Optimal Exercise Intensity for Individuals With Impaired Glucose Tolerance. Diabetes Spectrum 2001. 14(2); 93-97.