Please help me to understand this a little better. I train by going to my local community pool and swimming about 40 - 50 lengths underwater (obviously with a break in between! 
). I don't have a buddy to train with as there doesn't seem to be anybody interested in freediving around here. I never push myself past contractions if I'm on my own, but am I putting myself in danger of SWB? Can it happen literally at ANY time, or is it only when pushing your limits? I mean, can it happen to me if I have only been underwater for 20 seconds? Thanks for all your help,
Tom Arnold.
). I don't have a buddy to train with as there doesn't seem to be anybody interested in freediving around here. I never push myself past contractions if I'm on my own, but am I putting myself in danger of SWB? Can it happen literally at ANY time, or is it only when pushing your limits? I mean, can it happen to me if I have only been underwater for 20 seconds? Thanks for all your help,Tom Arnold.