Hey all-
I am not an expert on exercise and fitness (yet ;) ), but I am in PA school and learned something interesting that I think is relevant for here so I'm gonna pass it on.
We've all heard that you are not supposed to hold your breath while lifting, but the reason was not clear - at least not to me. When you hold your breath while you are straining, you are performing a maneuvar known in medicine as "valsalva". Think of it like holding your breath and bearing down as if to have a bowel movement. That's basically what you are doing.
When you valsalva, you are decreasing venous blood return to the right side of the heart thereby slowing your heart rate and lowering your blood pressure - creating a condition of hypotension. That's why people, especially beginners,feel light-headed when they work out. It's not necessarily a normal feeling to have when working out. (side note - the valsalva maneuver is responsible when old frail people pass out on the toilet)
As a practical exercise to demonstrate what I'm saying you could (be careful - I accept no responsibility for accidents) sit down, feel for your carotid pulse in your neck (gently now, massaging the carotid sinus in the neck has a similar effect), notice your heart rate, and then hold your breath while bearing down. You'll notice a dramatic and immediate drop in your heart rate.
This trick is also used by emergency medical staff to help people in crisis due to tachycardia.
This has been a "Science Minute" by Ansett. :D

Thanks man! Good info! Got any more tidbits like that?

Here's another little medical tidbit for you Collegefour. Many of us who have been involved in athletics have experienced running sprints. This sprinting is usually accompanied by very deep and heavy breathing. It is not uncommon for someone who has been exercising in this manner to have pain in the shoulder and neck region. Thinking they have sustained an injury of some sort, they often seek medical attention...usually a chiropracter. However, the most likely cause of the pain is the result of an overworked diaphragm from all of that heavy breathing. Think of the diaphragm in this case as a sore muscle. The nerves that supply the diaphragm (phrenic nerves) originate in the neck (cervical spine -- C3, C4, C5), and this is why pain from a sore diaphragm is referred to the neck and shoulders. If nothing else, this post may save you some money.

Hey thanks, that's very interesting!!

Sandman, I used get that sharp pain in my trap/shoulder region while in college especially during the first few minutes of hard running. I always assumed it was some cramping from drinking too much water. Thanks for the info and clearing that up.

Good one, Sandman!

That's some cool stuff! I always breathe to keep the oxygen/CO2 exchange going, plus it helps me relax while lifting.

That's some cool stuff! I always breathe to keep the oxygen/CO2 exchange going, plus it helps me relax while lifting.

I breathe for rhythm. The last thing I want is to start randomly sucking in air when I'm bringing those DB's towards my chest. :P

Waah all the medical terms! I can't find no sinus pulse =) I got pulse under my chin ( Like... You hyperventilate, press, faint... Those arteries ).. Where's the sinus pulse?

Hey all-
I am not an expert on exercise and fitness (yet ;) ), but I am in PA school and learned something interesting that I think is relevant for here so I'm gonna pass it on.
We've all heard that you are not supposed to hold your breath while lifting, but the reason was not clear - at least not to me. When you hold your breath while you are straining, you are performing a maneuvar known in medicine as "valsalva". Think of it like holding your breath and bearing down as if to have a bowel movement. That's basically what you are doing.
When you valsalva, you are decreasing venous blood return to the right side of the heart thereby slowing your heart rate and lowering your blood pressure - creating a condition of hypotension. That's why people, especially beginners,feel light-headed when they work out. It's not necessarily a normal feeling to have when working out. (side note - the valsalva maneuver is responsible when old frail people pass out on the toilet)
As a practical exercise to demonstrate what I'm saying you could (be careful - I accept no responsibility for accidents) sit down, feel for your carotid pulse in your neck (gently now, massaging the carotid sinus in the neck has a similar effect), notice your heart rate, and then hold your breath while bearing down. You'll notice a dramatic and immediate drop in your heart rate.
This trick is also used by emergency medical staff to help people in crisis due to tachycardia.
This has been a "Science Minute" by Ansett. :D

arnold says that u might burst yr lungs or something like that if you hold yr breath while lifting heavy weight. some people think u get stronger if u control breathing. i dont know what the truth is.

AniMe - Don't let the terms throw you. The point I was making was, if you feel light-headed or faint while you are lifting weights, it could be because you are holding your breath. So, you know, breathe. :tu:

Hah, I understood that, but still, I wanted to try your trick there ;)