Just a few minutes of light activity for people who sit most of the day - a short stroll or some squats at your desk every thirty minutes - can lower blood pressure for people with Type 2 diabetes, according to research presented at the American Heart Association's Scientific Sessions 2015.
Researchers tracked blood pressure levels in 24 overweight and obese adults with Type 2 diabetes as they sat for eight hours. Participants either took 3-minute walking breaks averaging a speed about 2 miles per hour (mph) or did 3-minutes of simple resistance exercises every half-hour. Compared to uninterrupted sitting:
- Light walking was linked to an average 10-point drop in systolic blood pressure (the top number in a blood pressure reading).
- Simple resistance activities were associated with an average 12-point drop in systolic blood pressure.
"It appears you don't have to do very much," said co-author Bronwyn Kingwell, Ph.D., head of Metabolic and Vascular Physiology at the Baker IDI Heart and Diabetes in Melbourne, Australia. "We saw some marked blood pressure reductions over trial days when people did the equivalent of walking to the water cooler or some simple body-weight movements on the spot."
Having both Type 2 diabetes and high blood pressure can significantly increase the risk of heart attacks and strokes.
Previous research has shown that sitting for long periods of time raises risks of obesity, high blood pressure, high blood sugar, high cholesterol and cardiovascular disease, and that short bouts of physical activity can lower blood pressure in overweight non-diabetic people.
Kingwell noted that this is the first study to examine effects of short intermittent bouts of light physical activity on Type 2 diabetes patients in a controlled lab setting.
Participants were men and women, average age 62, who were overweight or obese. About two-thirds of the participants were on medication to control blood pressure during the study.
For eight hours a day, on three separate days, they ate breakfast and lunch based on their calculated energy requirements. Researchers checked blood pressure and blood norepinephrine levels at regular intervals across the day.
For light-intensity walking, participants took a slow, easy stroll on a treadmill. For simple resistance activities, they did half-squats, calf raises, knee raises, or gluteal muscle squeezes.
Although it's not clear why taking breaks may help ease blood pressure for Type 2 diabetes, Kingwell said that muscles activated when you move increase blood sugar uptake, which is especially important among people with Type 2 diabetes since their bodies can't make enough insulin (or can't efficiently use insulin) to maintain healthy blood sugar levels. The parallel lowering in norepinephrine levels are also an intriguing candidate in relation to the blood pressure. Norepinephrine is a hormone that can raise heart rate and blood pressure.
"Light activity breaks are not meant to replace regular, purposeful exercise. But they may be a practical solution to cut down sitting time, especially if you're at your desk all day," Kingwell said.
For most people, the American Heart Association recommends at least 150 minutes of moderate exercise each week - such as walking around 3 mph - or at least 75 minutes of vigorous exercise each week - such as running at around 5 mph; or a combination of both.