Document Type : Research Paper
Authors
1 Department of Physiotherapy, Ardabil University of Medical Sciences, Ardabil, Iran
2 Department of Exercise Physiology, Faculty of Physical Education and Sports Sciences, Allameh Tabataba’i University, Tehran, Iran
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
Main Subjects
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