Oregon: New research from the University of Oregon reveals that taking antihistamine allergy pills before workouts may significantly reduce fitness gains. Published on May 30 in the Journal of Applied Physiology, the study found that histamine—a molecule known for causing allergy symptoms—also plays a critical role in exercise recovery and performance.
Researchers observed 16 participants over six weeks of cycling. Those who took antihistamines before each session experienced half the aerobic improvement compared to those given a placebo.
The findings suggest that blocking histamine restricts muscle blood flow and limits gene responses that support fitness adaptations. John Halliwill, lead author and physiology professor, explained that histamine helps the body adapt to physical stress.
Fewer proteins essential for muscle repair and growth are produced when it’s blocked. With allergy season in full swing, experts urge gym-goers to weigh the potential impact of antihistamines on their training progress.
