EFFECTS OF DOSE-RESPONSE OF NORDIC HAMSTRING EXERCISE ON MUSCLE PERFORMANCE IN ATHLETES, A RANDOMIZED CONTROLLED TRIAL

Background: The Nordic Hamstring muscle training is effective for eccentric strengthening of the hamstring in a sports population. Due to its high volume, its compliance is low and researchers are working to find out its lowest effective dose. Objectives: To determine the effects of dose-response of Nordic hamstring exercise on hamstring muscle performance. Methods: A randomized controlled trial was conducted from August to November 2020 and comprised of athletes of both genders who were randomized into high (3 times/week, 4 weeks) and low volume (1 time/week, 4weeks) Nordic hamstring exercise groups. The Outcome measures were taken using the single leg hamstring bridge test for hamstring strength, 30-m speed test, agility T-test, anthropometric measurement at 5cm, 10cm, 15cm above the patella. The assessments were taken at baseline, 2nd and 4th weeks. The data were analysed using SPSS 23. Results: There were 30(88.2%) males and 4(11.8%) females with a mean age of 23.41±3.67years and a mean BMI of 18.6±3.16. A significant difference (p<0.001) was observed between both groups for all outcome variables post-exercise protocol at 2nd and 4th week. Conclusion: The Nordic hamstring exercise was effective in improving hamstring muscle performance. The higher dose of Nordic Hamstring Exercise was more effective than the lower dose in improvement in muscle size, strength, speed and agility of the participants after 4 weeks of training. Keywords: Agility, athletes, hamstring injuries, muscle strength, nordic hamstring exercises, speed