Effects of Eight Weeks of Functional Training with Blood Flow Restriction and Betaine Supplementation on Follistatin, Myostatin, and Functional Outcomes in Older Women: A Randomized Controlled Trial Protocol

Aliakbari Jam, Faezeh; Shakoor, Elham; Zeynali, Farzaneh; Ashabi, Ghorbangol; Seyedi, Samaneh; Suzuki, Katsuhiko

doi:10.30476/whb.2026.109558.1383

Effects of Eight Weeks of Functional Training with Blood Flow Restriction and Betaine Supplementation on Follistatin, Myostatin, and Functional Outcomes in Older Women: A Randomized Controlled Trial Protocol

Document Type : Study Protocol

Authors

Faezeh Aliakbari Jam ¹

Elham Shakoor ¹

Farzaneh Zeynali ¹

Ghorbangol Ashabi ²

Samaneh Seyedi ²

Katsuhiko Suzuki ³

¹ Department of Exercise Physiology, Faculty of Sport Sciences, Alzahra University, Tehran, Iran

² Department of Physiology, School of Medicine, Tehran University of Medical Science, Tehran, Iran

³ Faculty of Sport Sciences, Waseda University, 2-579-15 Mikajima, Tokorozawa 359-1192, Japan

10.30476/whb.2026.109558.1383

Abstract

Background: Sarcopenia is characterized by age-related declines in muscle mass and function. Functional training with blood flow restriction (BFR) and betaine supplementation may improve anabolic adaptations; however, their combined effects in elderly women remain unclear. Therefore, this study aims to investigate their effects on serum follistatin and myostatin levels in elderly women.
Methods: This randomized, double-blind, placebo-controlled clinical trial protocol will enroll 56 community-dwelling older women (≥60 years) in Tehran, Iran. Participants will be randomized (1:1:1:1 allocation via a computer-generated sequence with allocation concealment) into four parallel groups (n=14 each) including functional training with blood flow restriction plus betaine (FBFR+B), functional training with blood flow restriction plus placebo (FBFR+P), betaine supplementation alone (B; 4 g/day), or non-exercising control (CON) for 8 weeks (exercise 3 sessions/week). Primary outcomes (plasma follistatin and myostatin measured by enzyme-linked immunosorbent assay) and secondary outcomes [muscle strength via 1RM bench/ leg press, functional performance via Timed Up-and-Go (TUG) and 10-Meter Walk Test (10-mWT), health-related quality of life (WHOQOL-BREF), and pain characteristics (McGill Pain Questionnaire)] will be evaluated at baseline and 48 hours following the 8-week intervention. Between-group differences will be analyzed using ANCOVA adjusted for baseline values, with significance set at P<0.05.
Discussion: This study will evaluate the effects of functional training combined with blood flow restriction (BFR) and betaine supplementation on serum follistatin and myostatin levels in elderly women. Findings from this research may inform future guidelines for non-pharmacological interventions to preserve muscle health, preserve independence, and manage sarcopenia in aging populations.

Keywords

Sarcopenia

Betaine

Follistatin

Myostatin

Resistance Training