Olympic 10km silver medalist and world champion Keri-Anne Payne explains the two major kinds of breathing patterns here, breathing bilaterally or only to one side. I personally don’t agree that you cannot switch between the two kinds of breathing patterns during a long distance event, for instance if single-laterally breathing swimmers want to catch a good view of the swimmer on their ‘blind’ side, or just to stretch out their neck a bit. But the video is nice :-)
