Background and Objectives: There is evidence that resistance training and protein intake can speed tissue repair following damage, and may therefore, be useful for accelerating recovery from exercise-induced muscle damage. Accordingly, the aim of this study was to study the role of resistance training and whey protein intake on delayed onset muscle soreness indices after eccentric resistance exercise in untrained men.

Materials and Methods: Twenty eight healthy untrained males of normal weight were randomly divided into 3 groups: supplement (n=10), placebo (n=10) and control (n=8), supplement group:  whey protein intake + 6 weeks of strength training, placebo group: placebo + 6 weeks of strength training, and control group. Creatine Kinase (CK), lactate dehydrogenase (LDH), hypertrophy (HYP) and maximal voluntary isometric contraction strength (MVC) were measured before, 24 hours and 48 hours after an eccentric resistance exercise involving knee flexion.

Results: Paired-samples t-test results showed that post training CK and LDH rates in place before exercise, 24 hours and 48 hours post-exercise in supplement group and 24 hours and 48 hours post-exercise in the placebo group were significantly lower than in the pre-training status, (p≤0.05). In addition, elbow and knee MVC and HYP in the supplement and placebo groups were significantly higher than in the pre-training status; and the increase in the supplement group was significantly higher than in the placebo group (p≤0.05).

Conclusion: The major finding of this investigation was that long-term whey protein intake combined with resistance exercise attenuated the impairment in delayed onset muscle soreness indices during the recovery from exercise-induced muscle injury.

Keywords: Creatine kinase, Lactate dehydrogenase, Hypertrophy, Maximal voluntary isometric contraction strength