The objectives of this study are to investigate the effects of short-time high-intensity interval training on tissue glucose and fat metabolism in healthy lean subjects and type 2 diabetic patients using modern and noninvasive imaging methods positron emission tomography (PET), magnetic resonance imaging (MRI) and magnetic resonance spectroscopy (MRS).

Inclusion Criteria:

The healthy patients

1. Age 40-55
2. BMI 18.5-30
3. Fasting plasma glucose less than 6.1 mmol/l
4. Normal glucose tolerance test (OGTT)

The type 2 diabetic patients:

1. Age-, sex-, and BMI-matched with the study subjects in the phase 1
2. In a good treatment balance
3. Glycated haemoglobin (HbA1c) less than 7.5 mmol/l
4. Two hours glucose value in oral glucose tolerance test (OGTT) less than 10.0 mmol/l

Exclusion Criteria:

The healthy patients

1. Blood pressure > 140/90 mmHg
2. Any chronic disease
3. Any chronic medical defect or injury which hinder/interfere everyday life
4. History of anorexia nervosa or bulimia
5. History of rest or exercise-induced asthma
6. Previous use of anabolic steroids, additives or any other substrates
7. Smoking of tobacco, taking of snuffs, or use of narcotics.
8. Significant use of alcohol
9. Any other condition that in the opinion of the investigator could create a hazard to the subject safety, endanger the study procedures or interfere with the interpretation of study results
10. Presence of any ferromagnetic objects that would make MR imaging contraindicated
11. Current or history of regular and systematic exercise training
12. VO2max >40 ml/min/kg

The type 2 diabetic patients:

1. Any other chronic disease than diabetes
2. Blood pressure > 140/90 mmHg
3. Any chronic medical defect or injury which hinder/interfere everyday life
4. History of anorexia nervosa or bulimia
5. History of rest or exercise-induced asthma
6. Smoking of tobacco, taking of snuffs, or use of narcotics.
7. Any other condition that in the opinion of the investigator could create a hazard to the subject safety, endanger the study procedures or interfere with the interpretation of study results
8. Presence of any ferromagnetic objects that would make MRI imaging contraindicated
9. Current or history of regular and systematic exercise training
10. VO2max >40 ml/ min/kg