The effect of myofibryl and sarcoplasmic hypertrophy training on muscle hypertrophy and strength

Objective: The aim of this study was to investigate the effects of myofibril and sarcoplasmic hypertrophy training on muscle hypertrophy, strength and selected anthropometric characteristics. Materials and Methods: A total of 30 healthy male volunteers aged 20-35 years participated in the study. Participants were randomly assigned to 15 myofibrillar (age: 25.13 ± 5.56 (years), weight: 83.95 ± 13.18 (kg), height: 178.10 ± 7.42 (cm), BMI: 26.42 ±3.58 (kg/m2)) and 15 sarcoplasmic (age: 25.41 ±5.90 (years), weight: 83.91 ±14.31 (kg), height: 177.37 ±7.56 (cm), BMI: 26.61 ±3.82 (kg/m2)) were assigned as hypertrophy training groups. The study was designed according to a pretest-posttest design to see the effects of eight weeks of myofibril and sarcoplasmic training. Anthropometric measurements included height (m), weight (kg), BMI (kg/m2) and circumference (cm) of the shoulder, chest, waist and dominant side upper arm and thigh. Pectoralis major (PM), latissimus dorsi (LD) and quadriceps femoris (QF) muscle imaging measurements were evaluated by an expert physician at Ordu University, Department of Internal Medicine, Department of Radiology using an ultrasonography device. For strength measurements, bench press, squat, and deadlift 1 RM measurements were taken before and after training. Results: There was a statistically significant difference between the mean pretest-posttest ultrasound data of the dominant side PM, LD muscles of the myofibrillar and sarcoplasmic hypertrophy training groups. There was a statistically significant difference between the pre-test and post-test ultrasound data of the non-dominant side PM, LD muscles of the myofibril and sarcoplasmic hypertrophy training groups. A statistically significant difference was found in the pre-test-post-test means of bench press, squat, and deadlift strength values of the myofibril training group. A statistically significant difference was found in the bench press and deadlift strength values of the sarcoplasmic training group in the pre-test and post-test averages. There was a statistically significant difference in the mean difference of bench press, squat and deadlift pretest-posttest strength data of myofibril and sarcoplasmic hypertrophy training groups. Conclusion: As a result of our study, myofibril hypertrophy training provided more hypertrophy than the sarcoplasmic training group according to muscle ultrasonography images. With this result, hypertrophy in muscle building was observed even if there was no difference in circumference measurements at the end of 6 weeks of training.