You pop a pre-workout supplement to score perks during your sweat session—so what’s with the headaches, the itchiness, the GI distress? Studies show that pre-workout supplements are safe for short term use, and they do indeed add perks to your performance. But considering they’re a combination of every ingredient but the kitchen sink, it’s no surprise that your body may feel a little irritated by certain blends.
The fix may be as simple as ingesting it with more water or narrowing in on a better brand for your body. So we tapped Lonnie Lowery, Ph.D., R.D., associate professor of exercise physiology and nutrition at the University of Mount Union in Ohio and co-host of the Iron Radio podcast to help determine what exactly is causing the most uncomfortable offenses. Here, read about headaches. Stay tuned for posts later this week on other pre-workout supp side effects.
Why does my pre-workout give me a headache?
It depends on the formula, but many have vasodilator compounds in them, or ingredients that cause your blood vessels to expand, explains Lonnie Lowery, Ph.D., R.D., associate professor of exercise physiology and nutrition at the University of Mount Union in Ohio. This dilates, among others, the blood vessels in your head, which can cause a headache.
The specific vasodilator is typically the amino acid arginine, which increases nitric oxide in the body. The idea behind including this is that at rest, a large part of your vascular beds are closed. If you open them up, in theory, you could take in nutrients or remove waste products better because you have more blood circulating. Some pre-workouts claim this may actually have anabolic effects and can cause muscle growth. But, if you keep getting headaches, see your doctor and consider switching to a supp that doesn't have this ingredient. (Though note that it might have other vasodilators that could cause the same problem.)