PNF training (C-R method) has a safe and better effect on hamstring muscle's flexibility, strength and endurance. To achieve the best combination and time in contracting and stretching process in PNF training for increment of several factors that can make simultaneously and effectively physical fitness, is controversial. The aimed of this semi-quasi study was determine and compare of the effect of 10 seconds of maximal voluntary isometric contraction and 10 seconds of passive stretching on strength, endurance and flexibility of hamstring muscle in nonathletes men. 20 non-athletes eligible male's subjects (20-25 yrs) were randomly divided in two groups. Independent variable, the implementation of six-week PNF training includes combination of 10 seconds of maximal voluntary isometric contraction and 10 seconds of passive stretching phases and 5 seconds rest in hamstring muscle. Dependent variables including strength, endurance and flexibility of the hamstring muscle. Data compared with paired and independent t test (p≤0.05). Means differences of flexibility, strength and endurance in comparison of pre and post test of training group and post test of two groups were significant. These results indicate that implementation of six-weeks of PNF training (C-R method) based on the overload principle with the combination of 10 seconds of maximal voluntary isometric contraction and 10 seconds of passive stretching, increased flexibility, strength and endurance of hamstring muscle in non-athletes male.
