Daily wisdom: why lifting makes you dizzy

Some athletes experience a brief dizzy sensation when doing loaded squats, which Shodan Rodney, a Tier 3+ trainer at Equinox Flatiron notes can happen if you don't eat adequate carbs before a heavy lifting session. Pete McCall, C.S.C.S, ACE-certified personal trainer, and adjunct faculty in exercise science at San Diego State University agrees that carbs could be the culprit, adding that it can also be a result of your breathing patterns during your lifts.

“Anyone doing heavy squats probably knows they should be eating to fuel the heavy lifts,” says McCall. He suggests having a snack of mostly carbs and a little protein such as an apple with peanut butter about an hour before your training session so that your blood sugar doesn’t drop, which could make you lightheaded. More surprisingly, watch the sugar content in any pre-workout drink. “You don’t want to have a concentrated dose of sugar too close to your training session since the rush could make you dizzy.”

However, the more likely cause of feeling faint is how you're breathing. “A lot of people hold their breath when they lift, especially for heavier weight,” he says. “When the diaphragm contracts, it creates internal tension that’s very important for stabilizing the spine.” But if you hold your breath for too long, or through several reps, you risk reduced oxygen to the brain, resulting in lightheadedness.

If you’ve fueled appropriately, check your breathing technique, says McCall. "Inhale at the top, then hold your breath a little as you’re lowering down under the bar’s weight. On the upward drive, exhale. Push against the floor while you breathe out to give you extra power,” says McCall. "Take a couple breaths at the top between reps."

You can also try forcing the exhale, which some lifters throwing around very heavy weights do by grunting, he adds.