IRONMAN® Ottawa 2025

Taking on an IRONMAN® is no easy feat, but doing so while breastfeeding comes with even more considerations and logistical challenges! It’s a challenge that Amanda took on and embraced in Ottawa. She stopped to use a pump three times on course (at the swim start, 95km into the bike bike leg and again in T2). Recent media stories have highlighted incredible tales of athletes who have taken on endurance challenges whilst breastfeeding and more research is needed to provide information on how the physiological demands are impacted. Amanda’s body will have been using more energy than usual in order to support her milk production. To keep her energy levels up, she consumed a stable intake of ~64g/h across the race, using a mix of bars, chews, gels and Carb & Electrolyte Drink Mix to avoid flavour fatigue, a common problem when completing events of this duration. After practising with 60g/h on the bike in training, Amanda increased her bike intake to ~73/gh during the race as she felt this better supporting her energy whilst racing and breastfeeding. She could have increased her intake further on the bike towards 90g/h to frontload her fueling, which may have helped to prevent the drop in energy she reported in the last 7km of the marathon.

Following our guidelines, Amanda preloaded with PH 1500 (Drink Mix), which will have aided water retention and ensured she started optimally hydrated ahead of the swim. She continued to stay on top of her fluid intake by consuming a range of drinks throughout the event, starting with two bottles of PF Carb & Electrolyte Drink Mix, before moving to pick up bottles of water on course and adding in her own PH 1000 (Tablets). Without knowing her exact sweat sodium concentration, Amanda aimed for a moderate concentration (close to the average of our sweat test database) to keep up with her sodium losses alongside the volume of fluid she was drinking. Getting a Sweat Test would allow Amanda to refine her sodium intake further in future races, but in Ottawa this hydration strategy worked well for her as she reported no issues with cramping and she said that she felt hydrated throughout.

Amanda's total caffeine intake was above what is recommended for endurance performance, but she still reported feeling like she was in a “black hole” after 35km of the run as it got towards night time, which she felt was likely due to her body wanting to go to sleep. Going forward, Amanda may benefit from optimising her caffeine timing, such as delaying her first caffeine dose until later in the race and then having larger doses to gain the mental stimulation effects when she needed them most.