loss of blood

when i was at the gym i was pushing close to my max on leg press and i noticed that after each set i would stand up and i would feel light headed and dizzy is this normal if not what can i do to fix this?

This is perfectly normal when you are really working legs heavy. Also, can happen when you are sitting for a long period of time. Think about what happens here. It all relates to relative blood pressure in parts fo the body.

There your legs are minding thier own business using just enough blood to keep the mostly dormant muscle fibers oxygenated. Then you come along and <BLAM> you're causing nearly every fiber in your quads to perform work at a very high level. So what happens?

They start calling out for more oxygenated blood and also for increased blood flow to remove the built up lactic acid from burning the store glycogen. Your body only has so much blood available so vasoconstrictors start activating in other areas of the bood to help 'squeeze' more blood towards your quads.

Now this is not a life threatening situation, it just means that there is less of an blood 'reserve' elsewhere in your body. Now, you finish your reps and stand up. Well, there's now a problem. Those vasocontrictors are still in 'squeeze' mode but you've now introduced gravity into the equation making it difficult for oxygenated blood to reach the brain immediately due to the decrease blood reserve.

So the brain starts to briefly run short of oxygen and, in response, starts to pull from non-critical areas (vision, balance, hearing) to keep the the ciritcal areas (breathing, autonomous nervous system, etc) supplied with oxygen. This last for as long as the vaso-contrictors (and vaso-diolators in this case) can be 'reprogrammed' which in most cases is no more than a couple of seconds.

Hope this helps.

Paul

A friend helps you move, a true friend helps you move bodies.

thanks

best thing to do after heavy leg presses is to sit there for a minute and put your head between your legs. this will get the blood back to your brain.

your body naturally gets the blood back in the brain when you pass out and fall to the floor.

Mayabe you weren't breathing or something.  

Thanks man, it's cool to know the science behind this sort of thing.