That’s important because blood sugar spikes after meals. In young, fit, people, insulin helps drive that sugar, glucose, into muscle cells and the liver where it’s stored for energy. This system becomes less efficient as we age, explained the study’s leader, Loretta DiPietro of the Department of Exercise Science at The George Washington University School of Public Health and Health Services.
Leaving too much glucose in the blood can not only lead to type 2 diabetes, but cardiovascular damage.That exercise helps prevent these effects is hardly news. That’s why experts recommend 45 minutes of exercise most days of the week.
But, DiPietro explained, many older people may not be able to, or motivated to, exercise for such sustained periods.
So in one of the first exquisitely-controlled experiments of its kind, DiPietro and her colleagues put 10 volunteers with an of average age of about 60, and with elevated, but not diabetic, levels of blood sugar, through three different two-day tests, each four weeks apart, in a special room designed for the purpose.
While their glucose levels were continuously monitored with an implanted meter, they exercised by walking on a treadmill for 45 minutes mid-morning, or for 45 minutes in the afternoon, or for 15 minutes half an hour after each tightly controlled meal by walking at a pace of about 3 miles per hour, what DiPeitro calls “the low end of moderate.” The first day of each two-day period, they did no exercise at all.
As expected, without exercise, post-meal blood sugar spikes were not well controlled. Both the mid-morning 45-minute treadmill session, and the three 15-minute sessions, controlled blood sugar over the 2-day period better than the afternoon 45-minute session.
But only the 15-minute walks managed to significantly reduce blood sugar spikes during the important three-hour post-meal window.
But only the 15-minute walks managed to significantly reduce blood sugar spikes during the important three-hour post-meal window. Walking could be one tool to help prevent diabetes in older people, the research suggests.
“This is not for weight loss, and it’s not going to increase your cardiovascular fitness very much,” DiPietro told NBCNews.com. “It’s very specifically for glycemic control with older age.” But, she added, everyone can benefit because we all experience glucose spikes after eating.
“If you’re sitting at your desk all day, and you eat lunch, go for a short walk,” she advised. “More than likely you won’t get that food coma.”
It could also be useful for pregnant women at risk for gestational diabetes,” DiPietro said, since, especially in late stages of pregnancy, women may not be able to exercise for 45 straight minutes.