Is IgE useful for Sport?

IgE (immunoglobulin E) is not a useful biomarker for general sports optimization. Its primary role is in type I allergic reactions (e.g., hay fever, asthma, food allergies). While exercise-induced allergies or asthma can affect performance, measuring total IgE does not guide training, nutrition, or recovery. Some commercial tests claim IgE can detect 'food sensitivities' that impair athletic performance, but the evidence is weak: systematic reviews find no consistent link between IgE levels and non-specific symptoms like fatigue or exercise intolerance. For athletes, more relevant markers include iron status, vitamin D, creatine kinase, and CRP. An IgE test may be justified if specific allergic symptoms occur during exercise (e.g., wheezing, hives), but then a specialist should measure specific IgE to individual allergens. Without clinical suspicion, routine IgE testing for sport is not evidence-based and risks unnecessary dietary restrictions or anxiety.