Research

Hormonal

Regular exercise training (aerobic or strength) does not increase circulating irisin levels in healthy, untrained adults, contradicting the hypothesis that irisin mediates health-related training effects.

Do not expect exercise to work by spiking irisin levels. This study shows that while your fitness improves significantly (running faster, stronger), your blood irisin levels do not necessarily rise. Focus on the performance gains rather than looking for this specific hormonal marker.

GoodRefutesHIGH confidence
A training-induced increase in circulating irisin could not be confirmed, calling into question its proposed involvement in health-related training effects.
Anne Hecksteden et al. · BMC Medicine · 2013

Why this rating

High-quality randomized controlled trial with 102 participants, though limited by the lack of tissue-level (muscle) data.

Source

Irisin and exercise training in humans – Results from a randomized controlled training trial

Anne Hecksteden et al. · BMC Medicine · 2013

DOI 10.1186/1741-7015-11-235

rct · n=102Cited 245×
Read the paper
DOI resolved against Crossref · corpus check 2026-06-10

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