Seeing stars while pressing 200+ pounds overhead or hitting a 400-lb deadlift isn't exactly ideal—but it is perfectly normal. It’s the physical reaction to drastic changes in your blood pressure.

It works like this: When doing a press or a lift, you’re contracting your muscles and holding your breath to create an internal pressure which increases your stability and localize your strength (called the Valsalva maneuver). But this combination also causes your blood pressure to spike dramatically, explains Brian St. Pierre, R.D., C.S.C.S., Director of Performance Nutrition at Precision Nutrition. “Once the lift is complete and you release the muscle contraction, your blood pressure drops dramatically, which sometimes causes people to become lightheaded or even pass out before the pressure can normalize,” he adds.

If your body is physically rising quickly (as with a deadlift, as opposed to a bench press), gravity isn’t helping the situation either—as you stand up, the motion shoots your blood down to your legs, temporarily constricting your brain’s blood supply and making you see stars.

The good news? Your blood pressure should normalize after just a minute or two of putting the weights down. The bad news? You can’t prevent that woozy feeling entirely. But you can mitigate the lightheadedness to a degree, St. Pierre says. For starters, when you're going into a lifting session, make sure you’re both well-hydrated and well-fed. If your body is dehydrated or low on sodium, that alone can elevate your blood pressure. Low blood sugar from a missed meal will contribute to feeling lightheaded.

And remember to breathe, says New York-based trainer Chris Ryan, C.S.C.S. Simply holding your breath cuts off the oxygen supply to your brain, which put you on the verge of passing out. “Especially on presses, people tend to hold their breath at the top," Ryan says. "When you have hundreds of pounds over your head and you’re fighting your breath for even just five seconds, you’re going to start feeling even more lightheaded."

Bottom line: Fuel up right, practice breathing (yes, seriously) on your big lifts, and don't panic if the world gets a little blurry for a moment when you set a new personal best in the deadlift.