Physical activity, along with proper nutrition, is the basis for the behavioral treatment of diabetes. In recent years exercise training in normobaric hypoxia is used in training programs for athletes and in rehabilitation. The aim of this study is the assessment of physical exercise in normobaric hypoxia condition on metabolic control of diabetes: blood glucose profile, its stability, HbA1c value, hypoglycemia: frequency, level, severity and time of occurrence, insulin demand, maximal muscle strength level, VO2max and anthropometric parameters.

Hypoxia leads to HIF-1 production (hypoxia inducible factor 1) which regulates expression of many genes (eg. gene responsible for erythropoetin production). It also stimulates angiogenesis, muscle hypertrophy and glycolytic energy production by transactivating genes involved in extracellular glucose import.

Before starting the training program all participants will be assessed by cardiologist. Then the incremental exercise test will be performed to determine aerobic capacity (VO2max).

Recruited patients ( type 1 male diabetic patients) will be divided into 2 arms: exercise in normoxia or in normobaric hypoxia. Hypoxic chamber is set to contain equivalent to an altitude of 2500 meters above see level (indoor air composition: 15,4% of O2 and 84,7% of N).

Training program will be the same for all participants: 60 minutes sessions twice a week for 6 weeks of mixed exercise: aerobic and anaerobic.

Glycemia will be monitored by Flash Glucose Monitoring (Free Style Libre) and the same glucometer model by all patients.

At baseline and after 6 weeks: echocardiography, ECG and incremental exercise test, ECG and blood pressure monitoring, lipid profile and diabetes control parameters will be performed in all patients.

Inclusion Criteria:

• type 1 diabetes of at least 10 years duration
• low physical activity
• BMI 20-30 kg/m2
• treated with multiple insulin injections (at least 4) or insulin pump (continuous subcutaneous insulin infusion [CSII])
• negative ECG exercise test
• HbA1c ≤ 8,0%
• high knowledge about functional insulin therapy, carbohydrate counting and diabetes management during exercise
• use of advanced glucometer functions and experience in use of Free Style Libre (Flash Glucose Monitoring System, Abbott)

Exclusion Criteria:

• HbA1c > 8,0%,
• advanced complications of diabetes [pre-proliferative or proliferative retinopathy, and previous laser therapy, microalbuminuria or overt nephropathy, autonomic neuropathy (including lack of elevated heart rate during physical activity)]
• patients physically active (regular physical activities more than once a week),
• positive ECG exercise test, history of cardiovascular event or coronary heart disease.