Long-term Adaptations of Skeletal Muscle After Hybrid Training

Long-term Adaptations of Skeletal Muscle in Overweight and Obese Individuals After Hybrid Training

Obesity is a major challenge for public health and renders it imperative to reduce its prevalence. High intensity interval training (HIIT) is a form of exercise training that can efficiently induce weight loss in adults with overweight or obesity, even in the absence of dietary intake manipulation. Hybrid type training represents a form of HIIT, that incorporates both cardiorespiratory and musculoskeletal stimuli, by combining multiple types of exercise into a circuit-type, interval style workout. Recent evidence suggests that long-term participation in hybrid HIIT results in significant health-related benefits. However, the molecular mechanisms driving the chronic effects of hybrid HIIT on cardiometabolic and musculoskeletal health remains to be elucidated.

A total number of 30 adults (both males and females) aged 30-50, meeting the inclusion criteria, will be enrolled in this study. Participants will be randomly assigned to either (i) a Control group or (ii) an Intervention group. The Intervention group will participate in three hybrid-type HIIT sessions per week over a 6-month period while receiving a balanced diet. The Control group will receive a balanced diet over the 6-month period but will not participate in exercise training. At baseline and 6 months, both groups will undergo assessment of their anthropometric profile, body composition, resting metabolic rate, muscle strength and cardiorespiratory capacity and provide resting blood and skeletal muscle samples.

Inclusion Criteria:

• BMI: >25 kg/m2 and <40 kg/m2
• Untrained individuals (abstain >1 year from exercise training)
• No dietary intervention over the last 6 months preceding the study
• Low cardiorespiratory fitness level (VO2max: <45 ml/kg/min)
• No use of any medication, dietary supplements
• Low risk for cardiovascular disease
• A weight loss <10% over the last 6 months preceding the study
• Free of non-communicable diseases (excluding metabolic syndrome)

Exclusion Criteria:

• Low participation rate (<80% completion of the exercise training sessions)
• Unbalanced diet
• Participation in additional exercise training regimes
• Cosumption of anti-inflammatory of pain relief medication