Mahe Drysdale has developed arthritis in his back and was so dehydrated in Beijing he had to be helped on to the podium, but despite pushing his body to breaking point for years the five-times world rowing champion cannot resist the lure of an Olympic gold medal.
While the New Zealander looks forward to the day he can eschew early morning starts sculling up and down Lake Karapiro and skip hours of road work on the bike, Drysdale's pursuit of gold may not end in London.
He might decide to "thrash" himself for four more years and compete in Rio in 2016, when he will be 37, he told Reuters by telephone before going to Europe for his final preparations.
"It's pretty clear that I will need to have some time out and do some different things and allow my body to have a bit of a rest," he said.
"I'm not ruling out Rio. That's a very inviting prospect. Four years, it'll still be doable in terms of my age, so there is a very strong possibility I will continue.
"But I just have to get through this year and see how it goes and then decide if I still have the passion and whether I want to thrash myself for another four years.
"I will be 37 (in Rio) and it's definitely in the prime of your rowing years."
Despite the physical toll rowing takes on the body, Drysdale said he was coming into his prime at 33.
"My take on it, looking at it around the world, is that you don't get any better after 35 or 36 but you can definitely stay at that level in your late 30s and some of the guys are still competing in their 40s.
"I want to keep my options open and then I can make a really good decision."
While he may take a break from competitive rowing after London he will remain fit mainly due to his competitive nature and the amount of work he has done to dominate the single sculls since 2005.
Having won three successive world titles, and seen off 2000 Olympic champion Rob Waddell in a row-off for the New Zealand seat, he was a raging-hot favorite to take the Olympic title in Beijing but was struck down by a virus.
Despite suffering from dehydration, he jumped out to a lead that he held until the final 100 meters before he was overhauled by 2004 champion Olaf Tufte of Norway and Czech Ondrej Synek.
A vomiting Drysdale was taken away for treatment and had to be helped on to the podium afterwards to receive his bronze medal.
It was his first loss in a competitive race since he switched to the boat from the coxless four after the Athens Olympics.
Pain in his back, which has since been diagnosed as arthritis, also contributed to his second loss in a competitive race when he finished second behind Synek on his home water at the 2010 world championships at Lake Karapiro.
That condition has meant he has had to manage his training workload. He no longer rows the land-based stationary rower, known as 'the erg', and has restricted the amount of time he spends on the water.
He now rows nine hours a week, though has increased his road cycling to 15 hours a week. Prior to the back condition worsening he was spending 18 hours on the water, with little time on his bike.
"It's just a case of managing (the condition) and I have to be careful and not do anything stupid. I'm careful with the amount of rowing I do and just work within my limits," he said.
"It has been quite a change but it's something we have found is needed to make up for the lack of time on the water.
"It has definitely kept me fresh because I have to make the most out of every row."
The disappointment of missing out on gold in Beijing was not the main reason he decided to have another tilt at the Olympics, Drysdale added.
"The decision to continue in 2008 was 'do I love the sport? Can I still improve?' And the answer to that was 'yes'," he said.
"It wasn't about I have to go win a gold medal. It is something I want to do but it wasn't the reason to continue.
"The Olympics is the pinnacle and I've only had one go at those in the single and this is my second opportunity so I want to make the most of it."
(Editing by Peter Rutherford)
(This has been refiled to remove superfluous word in intro)