Brisk walking regularly not only burn off calories, but will also lessen the diabetes risk provided you walk more, say Australian researchers. The researchers say 10,000 steps daily 5 days a week would be three times more protective in insulin sensitivity than 3,000 steps a day.
Recent increase in type 2 diabetes and obesity in many countries, including the United States and Australia, have been at least attributed to decline in physical activity.
Randomized controlled trials have shown that physical activity reduce body mass index and the progression to insulin resistance, but most were done in selected groups, such as people with impaired glucose tolerance or had composite interventions including diet as well as physical activity.
In the research study conducted in Tasmania, Australia between 2000 and 2005 to measure diabetes levels, 592 middle-aged adults participated. The study appears in the online edition of the British Medical Journal.
At the start of the study, the volunteers underwent a health examination and provided details about their eating and lifestyle habits. The participants were also given a pedometer (Omron HJ-003 or Omron HJ-102), printed instructions, and a diary to record daily steps.
The research study was intended to investigate the association between change in daily step count and both adiposity (fatness) and insulin sensitivity and the extent to which the association between change in daily step count and insulin sensitivity may be intervened by adiposity.
The study showed a higher daily step count in 2005 than in 2000 which was independently associated with a lower body mass index (BMI), reduced waist-to-hip ratio and better insulin sensitivity, even after adjusting for factors such as smoking, alcohol intake and diet.
We estimate that a sedentary person who takes a very low number of daily steps but who was able to change behavior over five years to meet the popular 10,000 daily steps guideline would have a threefold improvement in HOMA insulin sensitivity compared with a similar person who increased his or her steps to meet the more recent recommendation of 3,000 steps for five days a week, the researchers said in the study release.
However, over the five-year period, the daily step count decreased for 65 percent of participants. Although most participants had a decline in steps over time, more than a third had more daily steps by 2005, and 16.7 percent stayed in the persistent high steps category, the researchers say.
These findings, confirming an independent beneficial role of higher daily step count on body-mass index, waist-to-hip ratio and insulin sensitivity, provide further support to promote higher physical activity levels among middle-aged adults, the researchers say.
A guideline of 10,000-steps-a-day is approximately equivalent to 5 miles (8 kilometers) covered on foot, but the actual energy expenditure will vary depending on age, sex, height, leg length, and gait. An average woman’s step length is 67 centimeters and that for a man is 76 centimeters, meaning that a woman walks a kilometer in 1,493 steps and a man in 1,316 steps.
If the energy equivalent of walking 1 kilometer, based on the person’s body weight, is approximately 200 kJ (kilojoule) of energy, then an increase of 2,000 steps would equate to an added energy expenditure of approximately 268 kJ for women and 304 kJ for men.
The researchers concluded that an increase in physical activity over time, measured objectively by pedometer, is associated with better homeostatic model assessment (HOMA) insulin sensitivity. This apparent beneficial effect seems to be largely mediated through a change in adiposity.