Anabolic myokine responses and muscular performance following eight weeks of auto-regulated compared to linear resistance exercise in recreationally active males

Abstract

Background To date, no studies have compared the efficacy of auto-regulated periodized and linear resistance exercises on anabolic myokines and muscular performance among recreationally active individuals. This study aimed to compare the effects of an 8-week auto-regulated periodized resistance exercise(APRE) program with a linear resistance exercise(LRE) program on insulin-like growth factor-1(IGF-1), follistatin(FST), myostatin(MST), body composition, muscular strength, and power in recreationally active males. Methods Thirty males were randomly assigned to either the APRE group(n = 15) or the LRE group(n = 15). Participants completed training three times a week for eight weeks. The outcome measures included serum IGF-1, FST, MST, muscular strength(isometric knee extension, handgrip), power(vertical jump), lean body mass, and fat mass. Results IGF-1 circulating levels increased over time following APRE(34%), with no significant change following LRE(~-1%). There were no significant differences over time or between groups for FST or MST. Muscular strength(knee extension [21.5% vs. ~16%] and handgrip [right: 31% vs. 25%; left: 31.7% vs. 28.8%]) and power(~ 33% vs. ~26%) significantly increased to a greater extent following APRE compared to LRE. Interestingly, results revealed that lean body mass increased over time only after APRE(~ 3%), but not LRE. Conclusion These findings suggest that APRE may be more effective than LRE in increasing muscular strength, power, and lean body mass, as well as circulating IGF-1 levels, in recreationally active males. The observed differences may be attributed to the increased training volume associated with APRE. However, further research is needed to directly assess muscle protein synthesis.