Effect of Interrupting Sedentary Time With Different Frequencies of Physical Activity on Cardiometabolic Risk Factors

The knowledge gap on sedentary behavior and sedentary breaks includes whether detrimental effects of sedentary behavior can be fully attenuated by 1.) sedentary breaks 2.) physical activity or 3.) both combined. Specifically, when breaking sedentary time which physical activity pattern- and intensity modifies the negative effects of sedentary behavior on glucose- and lipid metabolism? This lack of quantitative evidence calls for prospective experimental studies investigating the physiological and biological impacts of sedentary behavior, as well as the effectiveness of different strategies to reduce sedentary time. Thus, quantifying effects of the intensity, frequency, volume and investigating the patterns of sedentary breaks and/or physical activity on predefined outcomes is of importance.Aims:Our primary aims are to investigate the effects of breaking up sedentary time on glucose- and lipid metabolism and thus examine whether pattern for sedentary bouts and breaks and physical activity intensity during sedentary breaks matter. Specifically, the aims of the PhD-project are to provide knowledge on the following questions:• How does different patterns of accumulation of sedentary bouts and breaks acutely influence glucose- and lipid metabolism under iso-caloric conditions?

Inclusion Criteria:Predominantly sedentary occupation.Physical activity: equal or less tham 150 minutes /weekNonobese. Central adiposity: Waist circumference equal or less than 102 cm for men and equal or less than < 88 cm for women. BMI < 30 km·m2Exclusion Criteria:Shift-workSmokingPregnancyCurrent use of medication, except from hormonal contraceptives.No presence of any co-morbidity (e.g. diabetes type 2, cardiovascular or cardiorespiratory disease, or other conditions known to affect carbohydrate and lipid metabolism - thyroid-, -liver or kidney).Systolic /diastolic resting blood pressure: > 140/90 mmHgFasting blood glucose concentration: > 6.1 mmol/LAbnormal total cholesterol, LDL, LDL or triglyceride concentrations (> 50% above recommendations)