Myths vs facts: LCT and Sport

Myths vs facts: LCT and sport. Fact: The LCT gene (rs4988235) determines adult lactose digestion ability. The myth that lactose intolerance directly impairs athletic performance is not supported. Many athletes with lactose intolerance tolerate small amounts of dairy or use lactose-free alternatives. No direct negative effect on endurance or strength exists as long as calorie and nutrient intake is adequate. However, gastrointestinal symptoms (bloating, diarrhea) from unadapted diets can affect training quality. Evidence: human-observational (lactose intolerance studies), but no specific RCTs on LCT and sport. Caveat: No single gene test can predict individual tolerance – challenge tests or symptom diaries are more reliable. Marketing claims that lactose intolerance 'ruins' performance are exaggerated.