Cluster Training in Female Volleyball Players

This study compares the effects of three different resistance training methods-traditional training, standard cluster training, and undulating cluster training-on strength, hormonal responses, and inflammation in female volleyball players aged 18-30 years. Thirty participants with at least two years of volleyball and resistance training experience were randomly assigned to one of three groups. All participants performed resistance training three times per week and volleyball-specific training two times per week for eight weeks. Blood samples were taken before and after the first session (acute response) and after eight weeks (chronic adaptation) to measure testosterone, cortisol, IGF-1, progesterone, and C-reactive protein (CRP). Performance tests included upper-body and lower-body strength (bench press and squat), speed, agility, and vertical jump. The main finding was that undulating cluster training produced significantly greater improvements in upper-body strength compared to standard cluster training, while all three methods were equally effective for lower-body strength and other performance measures. No significant differences were found between groups for hormonal or inflammatory changes. The study provides practical guidance for coaches seeking to optimize upper-body strength gains in female volleyball players.

Inclusion Criteria: * Female volleyball players aged 18 to 30 years At least 2 years of continuous training in volleyball and resistance training Complete health status (based on health and wellness questionnaire results) No anterior cruciate ligament injury or other upper-/lower-extremity injuries in the past 6 months Familiarity with basic resistance training techniques Non-pregnant, with regular menstrual cycles No regular use of medications (including oral contraceptives) No use of ergogenic supplements affecting muscle mass (e.g., anabolic steroids, growth hormone, or insulin-like substances) in the 6 months prior to the study Exclusion Criteria: * Absence from more than three consecutive training sessions Any musculoskeletal injury that prevented continuation of the training program