Picture yourself under the weight of a heavy barbell for a moment. You’re going for a PR today, and you’ll need to do everything right to tip the odds in your favor. After walking the weight out, you take your stance, adjusting your feet to the proper width and angle. You squeeze the muscles of your back and trunk to brace for the descent, and finally you take a big, deep, breath.

While this can be a natural instinct for anyone lifting a heavy object, you may know it by another name -- a Valsalva maneuver.

Named after Dr. Antonio Valsalva in the 1700s, the Valsalva maneuver occurs when you try to exhale against a closed glottis, which is the opening between your vocal chords that is sealed off by a flap covering the airway so food doesn’t end up in there.

After you breathe in, little to no air escapes the closed glottis, and the pressure in the abdominal cavity is increased. This is ultimately a good thing, as it makes the bony vertebral column of your spine more resistant to shear forces. In short, your back is likely to wiggle under a challenging load and this is not disputed at all.

Unfortunately, many pros and bros alike have advised folks to not invoke the Italian doctor’s namesake for fear that the risk of stroke, aneurysm, or blood pressure is “too high.” If you do a Valsalva you’ll surely have a stroke or blow a blood vessel and die, right? Wrong.

You see, like most things in the human body, the response to the Valsalva maneuver is nuanced and extraordinarily complex. (Editor's note: while all the details behind the Valsalva’s physiology and related epidemiology is beyond the scope of this article, we are fortunate enough to be able to link you to a 17-page article written by Jonathon Sullivan, MD, PhD, who also happens to be a Starting Strength Coach.) That said, here’s the quick and dirty on why both the pro and the bro who recommend not doing a Valsalva are sorely mistaken.

Yes, blood pressure increases during a Valsalva with values greater than 300mmHg (the top number). If that seems high to you, then you’ve been paying attention because the current recommendation is for most folks’ systolic blood pressure to be less than 140 and closer to 120mmHg. Again, there is no contention that performing a Valsalva increases blood pressure during exercise to a greater degree than without it.

That said, do we really see increased incidences of strokes, aneurysms or a greater risk of high-blood pressure secondary to doing the Valsalva? The short answer is no, no, and absolutely not.

You see, there are two types of strokes, hemorrhagic (bleeding from a ruptured blood vessel) or strokes from ischemia, which is when there is a lack of blood flow to an area of the brain due to a clot or an embolism.

For hemorrhagic strokes in the context of resistance training, we’re really talking about subarachnoid hemorrhages (SAH), aka a berry aneurysm. Since the other types are due to trauma like getting hit in the head with a baseball bat, a car accident, or falling -- stuff that doesn’t usually happen in a gym -- the biggest risk of SAH is having a large pre-existing aneurysm. Interestingly, the medical literature does not suggest that doing a Valsalva increases the size of one of these aneurysms, nor does it suggest that holding your breath actually makes them rupture. As Dr. Sullivan so eloquently points out in his article:

“Valsalva during lifting was associated with a lower risk than during sex, masturbation, anger, and blowing one’s nose.”

Now, in the case of the Valsalva during exercise increasing rates of ischemic strokes the answer is -- and you probably could’ve guessed this by now -- nope. In fact, it appears that resistance training, in general, decreases incidence of ischemic stroke from a variety of mechanisms.

What’s more, it appears that as a person either gets more fatigued or uses a more challenging load, they’re going to do a Valsalva anyway because it helps us transfer force to the bar more efficiently. Yes, Virginia, we’re all doing Valsalvas whether we want to or not and based on the evidence. It looks like it’s just fine.

Finally, does doing a Valsalva regularly during training lead to a greater incidence of high blood pressure? Not even close. In fact, resistance training actually lowers blood pressure consistently. Weight loss, which may be augmented by regularly training and compliance to an appropriate diet, is one of the most effective treatments for hypertension.

So here we are, about to go for that PR squat and having just learned that we’re going to do a Valsalva whether we want to or not. It’s not dangerous inherently, and it likely protects against injury. We should probably go ahead and hold our breath, tip our hats to Dr. Valslava, and be thankful for the gainzZz™.

Jordan Feigenbaum, owner of Barbell Medicine, has an extensive academic background including a Bachelors of Science in Biology, Master’s of Science in Anatomy and Physiology, and Doctor of Medicine. Jordan also holds accreditations from many professional training organizations and is a staff member for select Starting Strength Seminars. He’s been coaching folks since 2008 and as a competitive powerlifter, Jordan has competition best lifts of a 640lb squat, 430lb bench press, and 725lb deadlift as a 198lb raw lifter. He can be contacted via email at info@barbellmedicine.com.