It doesn't take much for those who are sedentary to make gains in terms of improving their energy metabolism. 

This is especially important for physically inactive people who are at an increased risk of heart disease and type 2 diabetes.

Excessive sitting combined with an unhealthy diet may mean energy intake (calories) exceed the body's energy expenditure, which could lead to a number of health issues. Lifestyle habits such as a sedentary behavior also affect the body's ability to switch between fats and carbohydrates for energy when necessary. That is what is considered metabolic inflexibility.

"A healthy body burns more fat at rest, but after meals and during high-intensity exercise, the main source of energy shifts to carbohydrates," said researcher Taru Garthwaite. "If metabolic flexibility is impaired, blood sugar and lipid levels can rise and, instead of being used for energy production, excess fat and sugars may be directed to storage."

The 6-month study looked at the 64 sedentary adults with multiple risk factors for cardiovascular disease and type 2 diabetes. The control group was not asked to make any changes to their lifestyle, but the intervention group was asked to reduce the amount of sitting they did by increasing their standing and other physical activity without starting an intentional exercise program.

Each participant's sitting time and physical activity was measured with an accelerometer.

"Our results suggest encouragingly that reducing sedentary behavior and increasing even light daily physical activity—for example, standing up for a phone call or taking short walks—can support metabolic health and potentially help prevent lifestyle diseases in risk groups," Garthwaite said.

Compared to those who remained highly sedentary, the study participants who reduced their sedentary time by at least 30 minutes a day showed improvements in metabolic flexibility and fat burning during light-intensity movement. In fact, the more someone increased their standing time, the more they were able to improve their metabolic flexibility.

"However, the positive metabolic effects of reducing sedentary behavior are likely to apply mainly to those who are physically inactive and already have excess weight and an elevated risk of disease," Garthwaite added. "Even greater benefits can be achieved by following the physical activity recommendation of 2.5 hours of moderate-intensity activity each week, but even a small increase in physical activity is beneficial, especially for those who are physically inactive."

Click here to read more in the Scandinavian Journal of Medicine & Science in Sports.