Biography:

John Halliwill is an academic expert on exercise and environmental physiology with an emphasis on responses of the cardiovascular system. He studies post-exercise hypotension, a condition in which a person's blood pressure drops after exercise. Halliwill has sought to identify hormonal, neural, or metabolic factors responsible for changes in the heart, vasculature, and muscles during exposure to environmental and physical stresses. He is also seeking to understand the mechanisms that underlie the beneficial effects of exercise. His work has been foundational in uncovering the role of histamine in adaptation to exercise. He has studied the conditions faced by astronauts, helped Olympic athletes prepare for competition in extreme environments, and tested equipment for the US Marines.

Recent Media:

• Smaller fitness gains found in healthy adults taking high antihistamine dose vs. placebo (Healio, July 14, 2025)
• Antihistamines could affect exercise recovery and gains, according to University of Oregon study (KLCC, July 14, 2025)
• My doctor told me to take my blood pressure at home. She didn’t tell me how hard it is. (Barron's, June 28, 2025)
• Are antihistamines antiworkout? (Drug Discovery News, December 2022/January 2023)
• Regular HIIT Exercise Enhances Health via Histamine (The Scientist, April 21, 2021)
• Are antihistamines worth it before a big workout? (Futurity, April 18, 2016)
• Should exercisers lay off the antihistamines? (OregonNews, April 14, 2016)