Walking/standing longer better for insulin sensitivity and lipid levels
Long low intense workouts more effective than an hour of physical exercise
Researchers have associated sitting for long periods of time with numerous health concerns including obesity and metabolic syndrome. In the research, Dr. Hans H. C. M. Savelberg, PhD, associate professor/director of studies and researcher at Maastricht University, Netherlands, along with colleagues, hypothesized that a daily round of exercise does not compensate the negative effects of inactivity during the rest of the day on insulin sensitivity and blood lipid levels.
For the study 18 healthy normal-weight young adults aged 19 to 24, with a median age of 21, followed randomly three physical activity regimes for four days.
For the first regime, participants were instructed to sit for 14 hours a day and not to participate in any form of exercise. For the second regime, participants were instructed to sit for 13 hours a day and have one hour of vigorous exercise and, for the third regime, participants substituted six hours of sitting time with four hours of walking and two hours of standing. The sitting and exercise regime had comparable numbers of sitting hours; the exercise and minimal intensity physical activity regimes had the same daily energy expenditure.
Researchers assessed physical activity continuously by using activPAL™, which records the time spent in sedentary activities (sitting) and quantifies upright time and activities including stepping bouts and activity intensity with a sub-second resolution over a plus seven day recording period, and used a diary.
Measurements of insulin sensitivity by using OGTT (oral glucose tolerance test) and plasma lipids were performed in the fasting state, the morning after the four days of each regime.
The results revealed overall that those who followed the strict sedentary regime, their daily energy expenditure level was about 500 kcal lower than in comparison to the other regimes. Cholesterol and lipid levels improved slightly when participants exercised vigorously for an hour each day, but improved significantly when participants were active for longer periods at low intensity.
According to the study, being active simply by standing or walking for long periods of time significantly improved insulin levels compared to both a strictly sedentary lifestyle, and one in which participants were largely sedentary except for an hour of exercise each day.
The researchers write in their conclusion; “One hour of daily physical exercise cannot compensate the negative effects of inactivity on insulin level and plasma lipids if the rest of the day is spent sitting. Reducing inactivity by increasing the time spent walking/standing is more effective than one hour of physical exercise, when energy expenditure is kept constant.”
The findings appear in the open access journal PLOS ONE.
More information on diabetes can be viewed online at the American Diabetes Association.
Associated Article; Dire health outcomes from extended sedentary time