I've seen that guy on discovery several times...a couple of years ago I decided I would try and triathalon. I started running (which wasn't bad b/c I was somewhat used to the treadmill) and the bike riding was fun, but when I started training for the swimming it about killed me. I don't think there is anything more demanding than swimming. I made it about 3 weeks and I decided that I wasn't going to go through with it. I was losing to much weight and I hated missing the gym to go swimming. I have a completely different appreciation for what this guy does not only swimming, but draggin his son in a raft. That is nuts.