The Story

This study came out of Doshisha University and the Human Performance Lab at Waseda University, Japan. Both institutes are highly respected in sports science. The results were published in PLOS ONE — one of the world’s biggest open-access scientific journals, where every paper is peer-reviewed and freely available for anyone to check.

The researchers asked a big question:
👉 Can neuromuscular electrical stimulation (NMES) actually make trained athletes’ abdominal muscles grow bigger?

They recruited 24 male collegiate track and field athletes — sprinters, hurdlers, jumpers, and throwers — already training at a high level.

What Did They Find?

• Rectus abdominis (six-pack): no growth.
• Obliques (side abs): no growth.
• Subcutaneous fat: no change.
• Body weight: no change.

Even with extremely thin abdominal fat layers (~0.4 cm on average — about three stacked credit cards), which should allow current to reach muscle easily, 20 Hz Neuromuscular Electrical Stimulation did not enlarge the athletes’ abdominal muscles.

Why Does This Matter?

• For athletes: If you’re already highly trained, 20 Hz NMES did not add muscle size. Think of it like pouring water into a glass that’s already full.
• For other users: Lower frequencies can still support circulation, relaxation, or recovery, even if they don’t create new growth in trained bodies.
• For busy people: Devices that reach higher settings (about 50–100 Hz) show stronger links to strength and size in multiple studies.

Study Summary

Research Reference

📊 EMS/ES Frequencies Tested in Studies (Compact)

🟢 Positive 🟡 Mixed/unclear 🔴 Negative

ORIEMS FIT Mission Reminder

This post is part of the ORIEMS FIT RESEARCH DIGEST series. Our mission is to make hidden studies accessible, strip away jargon, and inspire curiosity.

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Full Links & Institutes

• Wakahara & Shiraogawa — Doshisha & Waseda Univ., JAPAN — PLOS ONE (2019)
• Çelik et al. — Gazi Univ., TURKEY — Spinal Cord (2013)
• Ando et al. — Juntendo Univ., JAPAN — BMC Neuroscience (2021)
• Uno et al. — Waseda Univ., JAPAN — Scientific Reports (2022)
• Eriksson-Crommert — Örebro Univ., SWEDEN — J Electromyogr Kinesiol (2018)
• Ashida et al. — Sapporo Medical Univ., JAPAN — J Appl Physiol (2018)
• Shi et al. — Army Medical Univ., CHINA — J NeuroEng Rehabil (2023)
• Berger et al. — Karlsruhe Institute of Technology, GERMANY — J Sports Sci Med (2020)
• Lee et al. — National Taiwan Sport Univ., TAIWAN — PeerJ (2023)
• Sentandreu-Mañó — Univ. of Valencia, SPAIN — Scientific Reports (2021)
• Stefanou et al. — Univ. of Thessaly, GREECE — Ann Intensive Care (2016)
• Pérez et al. — Univ. of Granada, SPAIN — Pflügers Archiv (2002)
• Tanaka et al. — Toho Univ., JAPAN — Eur J Preventive Cardiology (2022)
• Choi et al. — Yonsei Univ., KOREA — Clin Endocrinol Metab J (2018) [PDF archive link used above]
• Mettler et al. — Univ. of Wisconsin, USA — Med Sci Sports Exerc (2018)
• Gondin et al. — Univ. of Burgundy, FRANCE — MSSE (2005)
• Evangelista et al. — UNESP, BRAZIL — Clinics (2019)
• Ulupınar et al. — Erzurum Technical Univ., TÜRKİYE — Journal of Exercise Science & Fitness (2025) [Elsevier/ScienceDirect]
• Kemmler et al. — FAU, GERMANY — Aging Clin Exp Res (2014, 2015)
• Vitale et al. — Univ. of Verona, ITALY — IJERPH (2021)
• Kelmendi et al. — Technical Univ. of Munich, GERMANY — Integr Cancer Ther (2024)
• Ruther & Dudley — USA — J Strength Cond Res (1995)
• Fessard / Gondin — FRANCE — Skeletal Muscle (2024)
• Frontiers Meta-analysis — International teams — Frontiers in Physiology (2021)
• Chen et al. — TAIWAN — Gynecol Obstet Invest (2010)
• Bundsen et al. — SWEDEN — Acta Obstet Gynecol Scand (labor pain; 150 Hz)
• Cabric & Appell — GERMANY/YUGOSLAVIA — Eur J Appl Physiol (1988)
• Aldayel et al. — Univ. of Queensland & Waseda Univ., AUSTRALIA/JAPAN — Eur J Appl Physiol (2011)
• Ultra-HF (10 kHz) preclinical — USA/CHINA — arXiv (2024)