Effects of an 8-week liquid protein supplementation on resistance training adaptations in untrained healthy college students

This study investigates the effects of 8 weeks of liquid protein supplementation on resistance-training adaptations in healthy, untrained college students. Thirty untrained male participants were randomized into two groups: a protein supplement (resistance training exercise (RTE) + protein) and a control (RTE). Both groups underwent resistance training exercises (RTE) three times per week for 8 weeks. The RTE + protein consumed a protein liquid supplement post-exercise, while the RTE consumed water. The results showed a higher degree of change in chest circumference (mean difference = 6.10 cm vs 3.36 cm), maximal bench press strength (mean difference = 16.00 kg vs 8.93 kg, P = 0.007) and maximal squat strength (mean difference = 42.33 kg and 27.32 kg, P = 0.018) in the RTE + protein group compared to the RTE group. Both groups demonstrated increases in thigh circumference, muscle mass, and maximal bench press and deep squat repetitions, but no significant differences were observed between the two groups. These findings suggest that post-exercise protein liquid supplementation can enhance the benefits of RTE on muscle strength and body circumference in young untrained adults. The study highlights the importance of post-exercise protein supplementation for beginners seeking to improve muscle performance, and future research should explore the long-term effects and optimal dosages of protein supplementation in different forms. This trial was registered with ChiCTR under the registration number ChiCTR2300076750.