I think it was the mango I received in my breakfast box that did it. After waking up hungry and eating a few slices at 2am I felt queasy, and by 4am I was heaving into the hotel toilet. When I threw up again at 5am I was doubting I could even walk to the starting line (let alone race). But right around this time my mates, Jenny and Chris knocked on my room asking if I was ready to go and I felt for the moment that I had purged my system and was getting stronger.
However by the time we gathered on the beach for the swim start an hour later I felt nauseous and rushed into the bushes to throw up yet again and then used the toilets. Again I felt slightly better afterwards. I was debating in my mind whether to start the race. Common sense suggested I go lie down and rest. But I had come so far and the warm, clear Andaman Sea looked so beautiful and inviting at sunrise - perhaps I could just do the ocean half of the swim segment then drop out? I was still undecided as my wave gathered for the start and I was surprised and unready when the gun went off. I stood there frozen for the longest time trying to assess my condition to swim (throwing up in the water would be gross and disgusting and unpleasant, but drowning seemed improbable). Suddenly the crowd of hundreds of supporters lining the beach-start noticed me standing there alone, the other 200 guys in my wave having already sprinted into the sea. I must have looked like such a sad and pathetic figure—pale, shivering with cold, staring anxiously at the ocean—and I am sure they all presumed it was my first triathlon and I was absolutely paralyzed with fear and scared to death to enter the open water. The spectators next to me erupted with shouting, trying to exhort me on: "you can do it!" "c'mon, it will be OK, you will make it".
In fact when I did then reluctantly trudge into the ocean and start swimming I felt better—somehow being vertical rather than horizontal seemed to help, the tropical water warmed me up, and my swim pace was so slow I was not exerting much effort (especially after catching a big slow guy who I drafted behind). When the later wave in red swim caps started passing us I picked up the pace slightly, and decided to swim the lagoon swim section, but felt weak again during T1. Again I tortured over whether to drop out or do some of the bike course. I knew the first section of course would take us through spectacular scenery and I kept thinking about how I had dragged my damn bike on such a long, circuitous journey. So after a languid 6 minute transition, I biked off after the stragglers.
A diligent bike marshal seemed to be constantly riding alongside me. I found this terribly odd - 'who cares if people this far in the back of the pack are drafting?' I kept thinking, having already mentally dropped out of any "race" and still fully intending to DNF.
I have placed a high value on maintaining adequate nutrition/fueling before and during endurance events of this distance. I am convinced that in previous events I bonked - failing to eat enough. Yet it is difficult to imagine I could have much less in my system than at this point on Sunday. After throwing up 5 times and the several bouts of diarrhea, I must have been running completely on empty. I did manage to ingest a single Espresso Love gel (of all things) on the bike. I guess the gel helped.
Upon finishing the bike I decided I would jog/walk part of the run. I ended up running all of the 12k run course in 57 minutes, which surprisingly was the 79th fastest run split on the day.
At the finish line, a friend rushed up to congratulate me and talk. "Thanks. I am going to be sick" I replied. I staggered away, desperately looking for a quiet out of the way spot. But it was too late, my stomach was already convulsing and I could not wait. The next thing in my path was a white tent. Which turned out to be the medical tent.
Needless to say, throwing up on the medical tent is a good way to generate a great deal of immediate and concerned attention. An absolute army of staff descended upon me. Doctors and nurses and people with stretchers and people with various medical apparatus. "Um, it was just a bit of bad fruit" I kept telling them. But all the young Thai nurses were lovely. And it was nice to get an IV - my appetite is only now really coming back as I write this two days later. One of the doctors suggested to me that generally in the future if one vomits so many times he would probably not recommend immediately doing a triathlon.
For what it is worth, my time was 3:47:10, placing me roughly in middle of pack.