Reducing sitting time alone doesn't improve endurance

"Low endurance is a clear risk factor for cardiovascular disease and even premature death. It is known that people who sit the most have the weakest endurance in the population, but based on previous research, we cannot say whether reducing sitting would help improve endurance," explains Jooa Norha, a doctoral researcher at the University of Turku.

The study was conducted at the National PET Centre in Turku to determine whether reducing sitting would have an impact on endurance. Sitting was reduced by an hour a day.

The study involved 64 middle-aged adults who engaged in too little physical activity for their health and sat a lot. In addition, the subjects were overweight or obese and had metabolic syndrome, or multiple risk factors for cardiovascular disease.

Their usual level of activity and sitting time was determined through four weeks of motion sensor measurements. Endurance was tested through a maximal fitness test on a stationary bike with breath gas measurements.

During the study, half of the subjects aimed to reduce their sitting time by an hour a day, while the other half continued sitting as usual, acting as the control group. Exercise was not encouraged, and reducing sitting was primarily accomplished by standing or increasing daily activities like walking or taking the stairs.

"Methods for reducing sitting were designed individually with each subject. We recommended, for example, using a standing workstation, walking while talking on the phone, or taking the stairs instead of the elevator," explains Norha.

Subjects continued in this manner for six months, after which endurance changes were tested. All subjects monitored their daily sitting and activity levels compared to their goals using a smartphone app linked to a motion sensor worn around the waist.

Although the group that aimed to reduce their sitting time was able to reduce their sitting time by an average of 40 minutes per day, their endurance did not improve compared to the control group.

However, when all subjects were examined, it was found that if they were able to increase their daily step count during the study, their endurance also improved. In other words, the more steps a subject could add to their day, the more their endurance improved.

While the harmful effects of sitting have been emphasized in recent years, this study suggests that reducing sitting time alone is not enough to improve endurance. To enhance endurance, it is necessary to engage in physical activity, such as walking or exercising.

HT