I have been a regular at my local gym twice a week for several years. When I exercise in the gym on an elliptical trainer I always try to limit my max heart rate to 162bpm (200-my age). I also try to burn as many calories as possible within that limit.
I usually work out for 40 minutes. My heart rate slowly builds through that time and in the last 10 minutes I either have to slow down or my heart rate will go above 162. But recently I have noticed that taking deep breaths and holding those breaths for 3-5 seconds seems to force my heart rate down although I am still exercising at the same pace. Does anybody know what causes this effect? It only works for a short period of a minute or two before I get totally out of breath and have to revert to rapid breathing again.