Introduction: Changes in lifestyle are responsible for an important part of the type 2 diabetes epidemic of the last decennia. Current guidelines for physical activity focus mainly on high energy expenditure advising 30 minutes per day moderate to vigorous physical activity (most often physical exercise). Recent studies suggest that sitting has negative metabolic effects independent of the time spent exercising (Duvivier et al. PLOS ONE 2013).

Low intensity physical activity (LIPA) -such as walking and standing- has been suggested to be an alternative to decrease the hyperglycaemic effect of sitting. Compared to exercise, LIPA might be a more feasible strategy. But, it remains to be determined whether reducing sitting time by replacing it by LIPA, results in lower 24 hour blood glucose levels and less blood glucose fluctuations (glycaemic variability) in type 2 diabetes patients and whether these effects are independent of the increase in energy expenditure

Methods: The study population will involve 19 people with type 2 diabetes (BMI: 25-35 kg/m2) who perform no, or only little, exercise and who are treated with diet only or with oral blood glucose lowering medication. They will perform three regimes of each four days: 1) a sitting regime, 2) an exercise regime and a 3) sit less regime. Daily energy expenditure of the exercise regime will be identical to that of the sit less regime. Sitting, walking and standing will be objectively measured by a 24 hour physical activity monitor. The energy spent during exercise will be standardised and quantified by using a bicycle ergometer; energy intake will be standardised as well. During each regime blood glucose will be measured with a 24 hour continuous glucose sensor.

Inclusion Criteria:

• Signed informed consent
• Men and women: 40-75 years old
• Diabetes mellitus type 2, developed after the age of 40 years old
• Treatment with diet or oral blood glucose lowering medication (metformin and/or SU-derivatives and/or DPP-IV inhibitors)
• HbA1c: < 10%
• BMI: 25.0 - 35.0 kg/m2
• Maximum 2.5 hours of MVPA per week (during last 3 months)
• Internet availability on a daily basis

Exclusion Criteria:

• Pregnancy or intention of becoming pregnant
• Alcohol use: > 2 units per day (during the last 3 months)
• Experimental drug use (during the last 3 months)
• Use of insulin, corticosteroids, vitamin K antagonists and immunosuppressive drugs in the last 3 months
• Triglyceride level > 10.0 mmol/L
• Fasting plasma glucose level > 10 mmol/L
• Heart failure NYHA 3 or higher
• Angina pectoris or signs of cardiac ischemia during exercise testing
• COPD Gold 3 or higher
• Glomerular filtration rate (GFR) < 30 ml/min
• Diagnosis of active cancer (not cancer in the past that is cured)
• Diabetes mellitus type 1
• Intermittent claudication with a walking distance < 500 meter
• Not able to cycle for ± 45 minutes, as judged from the incremental exhaustive exercise bicycle-ergometer test at Visit 1
• Based on historical information not able to walk for 3 hours per day and stand for 4 hours per day
• Mental or physical disability which makes physical activity not possible
• Participation in a clinical trial with medication use (in the last 3 months)
• Severe loss of vision
• Active foot ulcer or venous leg ulcer