Exercise plays an important role in treatment of diabetes. In recent years exercise training in normobaric hypoxia is used in training programs for athletes and in rehabilitation and also commercially. The aim of the study is to assess the impact of eccentric training conducted in conditions of normobaric hypoxia or normoxia and creatine supplementation on metabolic control: profile and stability of glucose concentration, HbA1c value, hypoglycemia and insulin demand, as well as the level of muscle strength, VO2max and anthropometric parameters

People with type 1 diabetes benefit from training in normobaric hypoxia - the composition of the air in the training room is: 15.4% oxygen 84.7% nitrogen, which corresponds to hypoxia at an altitude of 2,500 m above sea level. Hypoxia leads to the production of HIF-1 (hypoxia-inducible transcription factor ), which is a regulator of the expression of many genes responsible for angiogenesis, muscle hypertrophy and glucose stability.

Before starting the10 - week training program all participants will undergo preliminary examination by a cardiologist during which echocardiography and ECG will be conducted. Then the incremental exercise test and muscle strength test will be performed to determine aerobic capacity (VO2max) and select individual weights to train for each participant.

Patients enrolled to the study will be randomly assigned to one of the following 2 groups (training under normoxia or hypoxia conditions) and subgroups (with and without supplementation of creatine).

Randomization will be carried out in blocks of 4 people.

Training sessions will take place with the assistance of a personal trainer in the Hypoxia Laboratory and the Muscle Strength and Power Laboratory of Academy of Physical Education in Katowice twice a week for 60 minutes for a period of 10 weeks. The subjects will complete the same eccentric training program with individually selected weights.

Within whole training period glucose level will be monitored via Flash Glucose Monitoring system (Free Style Libre2). During training sessions concentration of asprosin (protein hormone encoded by the C-terminal region of the FBN1 gene, which encodes fibrillin-1 protein), irisin, GH (growth hormone), IGF-1 (Insulin-like growth factor-1) within blood serum immediately before and after the first and last training will be assessed.

At baseline and after 10 weeks blood count, Alanine aminotransferase (ALT), Aspartate aminotransferase (AST), creatinine, GFR (glomerular filtration rate), HbA1c, ACR (albumin-creatinine ratio) in a random urine sample, body weight, BMI, waist-hip circumference, body composition, quality of life according to the EQ-5D-5L (EuroQol Five-Dimension Five-Level scale), daily insulin requirement, incremental exercise test, muscle strength test (10RM-10 repetition maximum) will be investigated among all participants.

Inclusion Criteria:

• type 1 diabetes of at least 10 years duration,
• low physical activity,
• BMI:20-31 kg/m2,
• treated with multiple insulin injections (at least 4 daily) 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,
• experience in use of FreeStyleLibre2 (Flash Glucose Monitoring System, Abbott),
• Informed consent to participate in research signed by enrolled subjects

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