A 15-minute walk after each meal appears to help older people regulate blood sugar levels and could reduce their risk of developing type 2 diabetes, according to a small study.
Three short post-meal walks were as effective at reducing blood sugar over 24 hours as a 45-minute walk of the same easy-to-moderate pace, reported researchers with the George Washington University School of Public Health and Health Services.
Moreover, post-meal walking was significantly more effective than a sustained walk at lowering blood sugar for up to three hours following the evening meal, according to the study published June 11 on the website of the journal Diabetes Care.
“The findings are good news for people in their 70s and 80s who may feel more capable of engaging in intermittent physical activity on a daily basis, especially if the short walks can be combined with running errands or walking the dog,” Loretta DiPietro, PhD, MPH, the studys lead author, said in a news release.
“The muscle contractions connected with short walks were immediately effective in blunting the potentially damaging elevations in post-meal blood sugar commonly observed in older people.”
The findings, if confirmed by additional research, could lead to an inexpensive preventive strategy for a pre-diabetic condition that can over time develop into type 2 diabetes, DiPietro said. An estimated 79 million Americans have pre-diabetes, but most have no idea they are at risk.
Other studies have suggested weight loss and exercise can prevent type 2 diabetes, but this study is described as the first to examine short bouts of physical activity timed around the period following meals when blood sugar can rise rapidly and potentially cause damage.
DiPietro and her colleagues recruited 10 people ages 60 and older who were otherwise healthy but at risk of developing type 2 diabetes due to higher-than-normal levels of fasting blood sugar and to insufficient levels of physical activity. Older people may be particularly susceptible to impairments in blood sugar control after meals due to insulin resistance in the muscles and also due to a slow or low insulin secretion from the pancreas, according to the news release. Post-meal high blood sugar is a key risk factor in the progression from impaired glucose tolerance to type 2 diabetes and cardiovascular disease, DiPietro said.
Participants completed three randomly-ordered exercise protocols spaced four weeks apart. Each protocol comprised a 48-hour stay in a whole-room calorimeter, with the first day serving as a control period. On the second day, participants engaged in either post-meal walking for 15 minutes after each meal or 45 minutes of sustained walking performed at 10:30 a.m. or 4:30 p.m. All walking was performed on a treadmill at an easy-to-moderate pace. Participants ate standardized meals and their blood sugar levels were measured continuously over each 48-hour stay.
The team observed that the most effective time to go for a post-meal walk was after the evening meal. The exaggerated rise in blood sugar after this meal, often the largest of the day, frequently lasts well into the night and early morning, but the rise was curbed significantly as soon as the participants started to walk on the treadmill, DiPietro said.
Most people eat a big afternoon or evening meal and then take a nap or watch television. “Thats the worst thing you can do,” DiPietro said. “Let the food digest a bit and then get out and move.” A walk timed to follow the big evening meal particularly is important because this research suggests high post-dinner blood sugar is a strong determinant of excessive 24-hour glucose levels, DiPietro said.
The results of this study must be confirmed with larger trials that include more people, DiPietro cautioned, although this study monitored blood sugar levels continuously for 48-hour periods and carefully controlled the environment.
Read the study abstract: http://care.diabetesjournals.org/content/early/2013/06/03/dc13-0084.abstract.