In accordance with the limited studies about the effect of short and long-term creatine supplementation on exercise-induced physiological response, the present study will conduct to identify the effect of downhill running and creatine monohydrate loading on biochemical, inflammatory and performance indices of muscle soreness in male mountain climbers.
Methods: Twenty male volunteer mountain climbers (aged 22-28 year, fat 8-12, and VO2max 50-55 ml/kg/min) in a quasi-experimental, randomized and double-blind design will allocate equally into supplement and placebo groups. Each participant will receive creatine monohydrate or dextrose (0.3 g/kg body weight/day) for five consecutive days (Loading Phase). After the supplementation period, all subjects will participate in one bout downhill running protocol on a treadmill (-15% incline) for 30 minutes with 65% heart rate reserve (HRR). Biochemical (Serum creatine kinase: CK), inflammatory (Peripheral blood leukocyte count; Serum C-reactive protein: CRP; interleukin-6: IL-6; Thigh circumference and perceived soreness) and performance indicators (Flexibility, maximal isometric strength and explosive power lower limb) will determine in both groups during four phases (baseline, after the supplement period, immediately and 24 hours after the exercise). Serum CK, CRP and IL-6 will measure by photometric, immunoturbidometric and ELISA assays (with commercial Pars-Azmoon and Bendermed kits), respectively. The peripheral blood leukocytes counts will determine by automatic analyzer. Muscle circumstance and perceived soreness will determine by flexible tap and Talag Scale, respectively. Flexibility, maximal isometric strength and explosive power of lower limb will determine by wells, dynamometric and sargent vertical jump tests, respectively.