The effects of normal diet versus high protein diet on muscle hypertrophy and muscular strength in response to eight weeks body weight resistance exercise among male recreational athletes / Mohamad Firdaus Mohamad Zain

Diet strategy can improve muscular hypertrophy and muscular strength in response to bodyweight resistance exercise. The most prominent strategy to increase muscular hypertrophy and muscular strength is High Protein Diet (HPD). The purpose of this study is to determine the effects of high protein diet versus normal diet to muscle hypertrophy and muscular strength in response to eight weeks bodyweight resistance exercise among recreational male athletes. Thirty male students from SMK Siong volunteered as participants. They were divided into two groups; 15 participants in High Protein Diet (HPD) group (age 14.60 ± 1.12 y.o, weight: 48.77 ± 12.85 kg, height: 156.60 ± 10.60 cm, BMI 19.50 ± 3.50 kg.m-2) and 15 students in Normal Diet group (age 14.47 ± 1.06 y.o, weight: 53.97 ± 19.21 kg, height: 160.47 ± 10.33 cm, BMI 21.63 ± 5.35 kg.m-2) All participants followed same exercise included same warm-up, stretching, four types of bodyweight resistance exercise and cool down session lasted for eight weeks. Both groups consumed 2400 kcal but High Protein Diet (HPD) group need to consume 60% of carbohydrate, 10% of fat and 30% of protein while Normal Diet (ND) group need to consume 60% of carbohydrate, 30% of fat and 10% of protein. Both groups were prohibited to get extra proteins supplements including whey protein. The data was analyzed by using paired t-test and independent t-test. As the result for paired t-test, biceps and triceps circumference showed significant hypertrophy in both group (ND and HPD) after 8weeks of bodyweight resistance exercise when p-value for ND group is p= 0.001 while HPD p=0.001 after compared pre-test and post-test of bicep triceps circumference measurement. 1RM test for biceps curls showed significant increase when p-value for ND group was p=0.006 and p=0.001 for HPD group. For independent t-test, the data showed no significant difference for pre circumference both group when p=0.941 while pre-test for 1RM strength test also no significant difference when p=0.382. However, post-test for both vii group showed no significant difference for biceps triceps measurement when p=0.313 while post-test for 1RM biceps curl test also showed no significant difference when p=0.060. In conclusion, the present study found that both groups able to improve muscle size and muscular strength among male recreational athletes but high protein diet strategy found that this strategy do not distribute the effectiveness improvement on muscle hypertrophy and muscular strength in response to eight weeks body weight resistance exercise.