Focus on bike if you want big Ironman gains

Research finds advances in bike kit and training to be reason for faster IM times

Credit: Daniel Seex

In 1983, Dave Scott and Sylviane Puntous won the men’s and women’s Ironman Hawaii titles in 9:05:57 and10:43:36, respectively. In 2018, Patrick Lange and Daniela Ryf won in 7:52:39 and 8:26:18. The difference in of Kona-winning times is huge but, as investigated by a group of researchers, which discipline has enjoyed the greatest performance improvements in this period?


The team, led by Lucas Barbosa, analysed the top-three men and women each year between 1983 and 2018 and discovered that, perhaps not surprisingly, it was the 180km cycle leg that witnessed the greatest evolution. Men enjoyed a 16.9% boost; women, a staggering 26.4%. Swimming saw the slowest rate of performance growth – men just 3%, women 12.1%.

The reasons given for the cycle leg enjoying greater advances than the swim and run? Gear, of course, with time-trial bars, deep-rimmed wheels, lighter bikes and other aero accoutrements all cited. Greater understanding of aero positions, often via lab and wind-tunnel testing, also contributed.


Interestingly, women are catching the men thanks to an overall improvement of 20.8% versus the men’s 13.3%. An increased pool of talent is one reason given for the closing of the gender gap.