In 2014, a research team led by Professor Raphael Knechtle dissected the age and race times of all finishers in international events across Olympic- and long-distance. They collected data from 2003 to 2013 and concluded that the age of peak male performance in Olympic was 27.1 and 35.1 at Ironman. For the women, it was 26.6 and 34.4, respectively.
In the men’s 2016 Rio triathlon, Alistair Brownlee, then 28, was just above the top-10 average of 26.2. As for women’s winner Gwen Jorgensen, her 30 years nestled around the 29.6 norm. More recently again, 38-year-old Jan Frodeno was above the 35.2 of the men’s top-10 at Ironman Hawaii 2019; Anne Haug’s 36 years edged just above the 35.2 mean. Based on Knechtle’s research and our snapshots, men’s Olympic peak sits between 26-27 years old; women 27-30. At Ironman, both rise – men and women to around 35.
What does this tell us? In all honesty, gender divide’s less important than distance divide. And this is heavily down to muscle. Broadly, you have two types: slow-twitch and fast-twitch. The former’s greater for endurance, the latter for speed and power. Ageing causes a loss in lean muscle mass, but specifically fast-twitch fibres; in fact, there’s evidence that slow-twitch rises for a while as you age. Take this to Olympic racing and you can see why more powerful athletes tend to be younger, and why iron athletes are older.
While bone density and aerobic capacity decline with age, there’s an argument that older iron racers are mentally more resilient from years of high-volume training than younger athletes. Older iron athletes are also more likely to have dialled in nutritional and recover strategies, which are arguably even more important at longer-course racing.