[rogam44]

Off topic. I think blood pressure may be issue even in cycling if you do it in a wrong way. In early spring I went on my bike and I didn't follow first rule of cycling: "You will never cross the anaerobic threshold without a reason". My heart rate was at 198bpm on that bloody hill and at home I measured my blood pressure and values were 140/126.

I think that interval training may help you in apnea disciplines. It surely helps me.

Jiri B