A discussion on a forum some months ago:

Question: “Today when I completed a Power Clean, I nearly blacked out. Extreme dizziness, complete silence, unable to see clearly, jello limbs, etc.

I don’t really pay attention to my breathing. I breathe out (grunt out) at the top of the lift. Then hold my breath as I lower it. The dizziness is worst at the top as soon as I’ve racked the barbell on my shoulders.“

Forum Members: “Don’t use the Valsalva maneuver: don’t hold your breath. You could get dizzy and faint.“

“You can damage your eyes if you don’t breathe while doing heavy lifts. Your eyes are the first to give out if internal pressure is too great.”

“Exhale during the concentric phase and inhale on the eccentric phase. Failing to breathe properly builds up pressure in all the wrong places.”

Valsalva Maneuver. When you move a heavy object, you take a big breath, hold it & exert force. Whether you push your car of move a piece of furniture. Holding your breath is something you do naturally.

Breathing in strength training is the same. Big breath. Hold breath during the lift. Breathe between reps.

Why You Should Hold Your Breath. Your lower back supports the weight from the back. Your abs from the front. Holding your breath increases the pressure in your abdominal cavity. You’re adding front support, helping your back.

Exhale during a Squat & the pressure in your abdomen decreases. Your lower back gets all the weight. Holding your breath is safer.

Eye Damage. This comes from the study on eye damage & weightlifting.

The 30 volunteers had to Bench Press 4 reps in 2 different ways:

1. Holding their breath during the 4 reps
2. Breathing normally during the 4 reps

While they were holding their breath, pressure in the right eye was measured. While they breathed normally, pressure in the left eye was measured. In both cases eye pressure was measured during the last rep.

• When they held their breath eye pressure rose 4.3 mm of mercury (average) in 90% of the weightlifters.
• When they breathed normally eye pressure rose 2.2 mm or mercury in 62% of weightlifters.

The researchers concluded that prolonged weightlifting might be a potential risk factor for the development as well as the progression of glaucoma.

First. Nobody should hold his breath for 4 reps. Breathe between reps. Second. Your body adapts. You gain muscle, you become stronger, your cardiovascular system adapts and whatever else is needed to lift big weights.

Five millions weightlifters worldwide participate in championships & use the Valsalva maneuver.

• Find a video of an Olympic weightlifter breathing during a lift.
• Find a weightlifter who injured his eye because he held his breath.

I’ve been lifting for 10 years, I’m still waiting for it to happen.

Fainting. Back to the original question. The poster could have faint for several reasons:

• Bad day. Illness. Poor nutrition.
• Bad shape. Overweight. Fat. Just started training.
• Received the bar against his throat on the power clean.

I suspect number 3. Positioning the bar against your throat on Front Squats & Power Cleans can make you dizzy. Work on your technique. Increase weight progressively. Let your body adapt.

How You Should Breathe. Get ready for your lift. Take a big breath. Hold against your glottis. Move the weight. Breathe between reps. Feel free to grunt on the way up.

The Valsalva maneuver happens naturally. Don’t think about it. Trust your instinct. You’ll be ok.