Myths vs facts: SHBG and Sport

SHBG (Sex Hormone Binding Globulin) is a carrier protein for sex hormones. A common myth is that high SHBG always means low free testosterone and thus impairs athletic performance. In reality, SHBG levels are influenced by many factors including insulin, thyroid hormones, diet, and exercise type. Endurance training tends to increase SHBG, while resistance training may decrease it. However, the relationship between SHBG and performance is not straightforward: free testosterone, receptor sensitivity, and overall hormonal balance matter more. Current evidence is mostly mechanistic and observational; no large RCTs directly link SHBG manipulation to sport performance gains. Therefore, using a single SHBG value to predict athletic ability is not evidence-based. Athletes should consider comprehensive hormone assessment and consult a specialist. Caveat: Do not self-treat based on SHBG levels alone.