Creatine Supplementation during Suspension Training Reduces Circulating Myostatin Without Additional Improvements in Physical Function in Inactive Older Men: A Randomized Placebo-Controlled Trial

Beigi, Armita; Tartibian, Bakhtyar; Eslami, Rasoul; Azadpour, Noushin; Fasihi, Leila

doi:10.22054/nass.2026.93780.1242

Creatine Supplementation during Suspension Training Reduces Circulating Myostatin Without Additional Improvements in Physical Function in Inactive Older Men: A Randomized Placebo-Controlled Trial

Document Type : Research Paper

Authors

Armita Beigi ¹

Bakhtyar Tartibian ¹

Rasoul Eslami ¹

Noushin Azadpour ²

Leila Fasihi ¹

¹ Department of Exercise Physiology, Faculty of Physical Education and Sports Sciences, Allameh Tabataba’i University, Tehran, Iran

² Department of Physiotherapy, Ardabil University of Medical Sciences, Ardabil, Iran

https://doi.org/10.22054/nass.2026.93780.1242

Abstract

Methods: In this randomized, double-blind, placebo-controlled trial, 22 inactive older men aged 65–85 years were assigned to suspension training plus creatine (TRX+Cr; n = 11) or suspension training plus placebo (TRX+Pla; n = 11). Both groups completed a supervised 6-week suspension training program. The TRX+Cr group received creatine monohydrate at 0.3 g·kg⁻¹·day⁻¹ throughout the intervention, whereas the TRX+Pla group received placebo. Outcomes included appendicular skeletal muscle mass index (ASMI), serum myostatin, follistatin, insulin-like growth factor-1 (IGF-1), vitamin D, handgrip strength, five-times sit-to-stand (5xSTS), and Short Physical Performance Battery (SPPB). Between-group differences were analyzed using ANCOVA adjusted for baseline values.

Results: Creatine supplementation produced a greater reduction in circulating myostatin compared with placebo (p < 0.001). A significant between-group difference was also observed for follistatin (p = 0.002); however, this reflected a decrease in the creatine group and should not be interpreted as a favorable anabolic response. ASMI did not differ significantly between groups (p = 0.051). No significant between-group differences were observed for IGF-1, vitamin D, handgrip strength, 5xSTS, or SPPB.

Conclusion: Creatine supplementation during 6 weeks of suspension training reduced circulating myostatin in inactive older men, but this biomarker response was not accompanied by statistically significant additional improvements in ASMI, physical function, IGF-1, or vitamin D.

Keywords

Creatine supplementation

suspension training

inactive older men

myostatin

muscle-related biomarkers

physical function

Subjects