People have asked me what is the best way to exercise. (To get the health benefits of course, but they also want to know how best to exercise to lose weight.) To which I have always answered with "high intensity interval exercise". People would then reply, "Huh?"
This is because nobody talks about high intensity interval exercise. But experts in the fitness world have been big about interval training for a long, long time because of results they have seen among themselves and their clients.
Lately, the scientific communities that study the fitness part of the health equation are becoming big about interval exercise too. They have shown in small studies that people who are obese lose more weight by interval exercise than by continuous exercise.
A radio story on my local National Public Radio station reminded me of this. It describes a small study where people with diabetes were requested to exercise by the high intensity interval approach. They were told to walk -- yes walk, not run -- for 3 minutes at a slow pace followed by 3 minutes at a fast pace, then slow, then fast, and so on for 1 hour everyday.
A 2nd group of people with diabetes were told to walk at a continuous pace for 1 hour with no change in their rate of walking. A 3rd group was told to carry on with their daily routine. The study went on like this for 8 months.
What did the researchers expect? That both exercise groups would have better blood glucose control -- a critical health goal for diabetics -- than would the 3rd group. But the results surprised them.
The group that exercised for 1 hour every day at a continuous pace showed no improvement in their blood glucose control. But the group who exercised for 1 hour every day by the high intensity interval approach improved their blood glucose control.
The NPR journalist said: "their glucose disposal — the ability to move sugar out of the circulating bloodstream and into parts of the body where it can be used as fuel — improved by 20 percent compared with the nonexercising group. And their hemoglobin A1C levels, a longer-term measure of blood sugar dipped slightly too.
If blood glucose control was improved by fast then slow walking, just imagine what people can do by jogging, bicycling, swimming or running in the same fast and slow interval! So why did the people who exercised for the same amount of time -- but in fast and slow interval -- have such different results?
One of the experts told NPR, "'It's this switch between the intensities that we think is critical here,' says Solomon. 'You're able to work hard, and then rest hard ... rather than just walking at a fixed pace... And during the high-intensity bursts, your muscles need more fuel in the form of glucose.
"'It makes sense that intervals would help people with blood sugar control,' says Dr. Tim Church, a professor of preventive medicine at the Pennington Biomedical Research Center in Baton Rouge, La.
"He explains that our [skeletal] muscles are the No.1 consumer of blood sugar in our bodies.
"So, when we do things such as short bursts of high-impact aerobic activity, 'you're pulling excess sugar out of the blood, which results in healthier blood sugar levels,' Church says."
So the Healthy Indian knows to get better results -- for the health benefits, to lose body fat too -- to exercise by high intensity interval, or basically to go fast for a few minutes when walking, jogging, running or any aerobic, then slow for a few minutes, then fast, then slow and so on instead of spending a really long time in the gym.
Read more about this study in NPR's story here.