The Effect of Frequency and Duration of Breaks in Sitting Time on Metabolic Cardiovascular Risk Factors

Fifteen (n=15) sedentary adult overweight males will be included in the study. All participants will undergo the four interventions in a randomized cross-over design. Wash out between intervention will be minimum four days.

Control (CON): Participants will be sedentary. Sedentary time will be spent sitting in a chair, restricted to sedentary behaviors (working on a computer, reading, watching TV, etc.), with a target MET below 1.5 (i.e. 1.5 times REE). Participants will only be allowed to stand or walk to go to the toilet.

Breaker: Participants will be breaking up prolonged sitting with 2 min intervals of low intensity walking.

Intermediate: Participants will be breaking up prolonged sitting with 6 min intervals of low intensity walking

Prolonger: Participants will be breaking up prolonged sitting with 12 min intervals of low intensity walking

All interventions will be matched for total physical activity as well as sitting. Thus, we aim for the active interventions to be iso-caloric.

Inclusion criteria

• Males, age 20-50 years, waist-to-height ratio ≥ 0.5 and/or waist circumference ≥ 102 cm.

Exclusion criteria

• Clinically diagnosed diabetes, uncontrolled hypertension, use of glucose- and/or lipid-lowering medication, smoking, evidence of thyroid, liver, lung, heart or kidney disease, non-sedentary occupation, and VO2max levels above the considered average fitness according to age (Shvartz & Reibold 1990), contraindications to increased levels of physical activity.