Interval training is a fitness practice that anyone can use, no matter what their level of activity. You alternate periods of light exercise, or even rest, with periods of relatively intense exercise - depending on your fitness level. You can do this when walking, running, biking, swimming, or using a stationary bike or other aerobic gym machine. If you don’t enjoy exercise ‘that much’, but know you should do it, of if you are short on time, the big advantage of interval training is that you can get results quite quickly. According to Martin Gibala, professor of Kinesiology at McMaster University in Ontario, 20 minutes three times a week is the usual time commitment. In these 20 minutes, you alternate recovery periods with hard effort. The protocol used by Gibala involves speeding up to 85-90% of your maximum heart rate for one minute, and then slowing down for one minute - you keep doing this 10 times during the 20 minutes.
So far, trials of this method have shown that interval training makes the heart a better pump, makes blood vessels more elastic, and makes muscles better at using oxygen. Average blood sugar levels were reduced after two weeks of interval training, in people with and without diabetes. This happens because exercised muscles have greatly enhanced ability to take up blood glucose.
People rode stationary bikes in the McMaster studies, because of the safety of this exercise, and the relative ease on joints. It’s important to realize that people can start interval training at any level of fitness. If your usual exercise is walking around the block, or around your neighborhood, try alternating faster walking for a minute with slower for the next minute, and keep this up for 20 minutes. You don’t have to sprint if you are not used to doing so!
You should talk to your doctor or nurse practitioner about any proposed new exercise program if you have been inactive. Remember - it’s also risky to sit on the couch all day!
A recent study from the University of Copenhagen in Denmark showed that for people with diabetes- alternating levels of walking intensity could be much more effective than walking at constant speed to help manage blood sugar. They measured insulin secretion after a glucose infusion, and did skeletal muscle biopsies, before and after a 4 month training period. Only the people who had been given interval walking training showed improved blood sugar control and increased insulin sensitivity in in skeletal muscle. People who walked a comparable amount of time without interval training were the comparison group.
I love to walk and daydream, sing to myself, or talk with friends as I stroll. Whatever activity you like to do - carry on. Interval training can be effective if done only 3 times a week. “If it’s physical, it’s therapy” were the words on a t-shirt I saw long ago in Golden Gate Park. Here are some other great t-shirt slogans:
I got my shit together with a Clivus Multrum.
Fighting terrorism since 1492 (a group of Indians with long rifles)
Some Day my Prince will Come - and I wanna come too.
But I digress. See you on the road, looking at your stopwatch.