Hold breath or breathe out?

I was doing swimming drills (mostly balance drills) at the pool the other day and while doing these a triathlete that also happens to be an anesthesiologist watched me without me being aware of this. When I got out of the pool he told me that he was watching me and while he said that I did the drills well, he also said that I was holding my breath, which I wasn't aware of. He then explained to me that if I did hold my breath, the heart had to pump harder to get the blood into the lungs because of the higher pressure in the lungs. He then went on to explain to me that if I continued to do this, over time my right ventricle would thicken and if I remember right this could lead to heart activation problems. So he advised me to always exhale in the water to avoid this problem. He also told me that holding breath once the lungs are empty is ok, because there is no pressure left in the lungs at that time. My two cents...

I was doing swimming drills (mostly balance drills) at the pool the other day and while doing these a triathlete that also happens to be an anesthesiologist watched me without me being aware of this. When I got out of the pool he told me that he was watching me and while he said that I did the drills well, he also said that I was holding my breath, which I wasn't aware of. He then explained to me that if I did hold my breath, the heart had to pump harder to get the blood into the lungs because of the higher pressure in the lungs. He then went on to explain to me that if I continued to do this, over time my right ventricle would thicken and if I remember right this could lead to heart activation problems. So he advised me to always exhale in the water to avoid this problem. He also told me that holding breath once the lungs are empty is ok, because there is no pressure left in the lungs at that time. My two cents...