We are evolving beings. No, I’m not pulling a quote from Charles Darwin’s ‘On the Origin of Species’. I’m referring to the way we evolve through experience and refine how our body and mind interact.

As an endurance athlete, I’ve certainly evolved my understanding of what my body is telling me at different stages of a season, a training week or during a specific race scenario. What I may have once perceived as ‘good fueling’, I may now see as inadequate. Or what I may have considered signs of dehydration in the past, I now understand that I’ve perhaps underdone my sodium intake.

Lessons from the field

I remember being 38km deep into the marathon during the 2016 Challenge Wanaka Triathlon. I had about an eight-minute lead when both hamstrings cramped up. While I managed to grovel to the finish and take the victory, I was left a little traumatised by the threat the cramp presented at such a critical moment in my race. Never again, I thought to myself, would I put months of training and preparation into an event but leave my race day nutrition to chance like this.

It wasn’t that I hadn’t made a plan of what to eat and drink, it was just that I hadn’t really broken that plan down in order to truly understand what I needed and when I needed it during the race. On this occasion, I let my guard down late in the race, but I quickly learned that it ain’t over until you cross the line.

Image Credit: Finlay Woods ©

This was a turning point for me and I’m now more thorough in my race day nutrition planning. I've individualised my plan based on experience, practice and past mistakes. As a passionate student of the sport, I’m always refining my strategy based on the unique learning that each race offers and the way the research continues to offer insights into how best to optimise nutrition strategies.

My IRONMAN Fueling and Hydration Strategy

Below is an example of the nutrition plan I developed for the bike leg of IRONMAN New Zealand in 2020. I believe the cycling phase of a full-distance triathlon is pivotal from a nutrition standpoint as it can form the backbone of a pleasing performance - if you get it right…

Stage Food Carb (g) Sodium (mg) Caffeine (mg) Fluid (ml)
180km bike, 4.5hrs 1x PURE fluid gel (orange) on run to bike 26 30
Lap 1 2x PH 1500 tablets per 750ml bottle on bike 3000 1500
6x Clif Bloks - Margarita 46 300
7x Maurten Gels 154 238
1x water bottle @ aid station 700
Lap 2 1x 1L PH bottle w 2x PH 1500 tablets + 2x No-doze tablets 1500 200 1000
2x 1/2 bananas @ aid stations 30
2x water bottles @ aid stations 21 1400
6x PURE banana/honey gels 126 324
6x Precision Hydration Electrolyte Capsules 1500
Totals 403 6892 200 4600
Requirements 405 6750 4500

I swam and biked solo all day, then managed to run through a number of tiring athletes on the marathon to finish 5th with a marathon time of 2:51. A big influence on my day was definitely the nutrition I managed to consume based on my plan during the 180km ride.

You will note that I plan my carbohydrate, sodium, caffeine and total fluid requirements based on the duration (and to some extent the expected climate) for the race.

On this occasion, my targets were 90 grams of carbohydrate, 1500mg of sodium and 1000ml of fluid every hour. I also took 200mg caffeine at approximately 95km into the bike phase after collecting a bottle at the special needs station.

Know Your Numbers

I haven’t just made these numbers up or taken them from a text book or generic training plan. I’ve refined my carbohydrate intake through practice, I’ve taken a Sweat Test (to nail down my sodium losses) and measured my sweat rate to understand my fluid losses in different conditions. And recent research and personal experience has helped me work out how much caffeine I need for high performance.

Ultimately, I have trialled these numbers in key simulation sessions in training and trained my gut accordingly.

In the heat at Challenge Roth in 2017, I was trying to consume 70-80g of carbs per hour on the marathon. The projectile vomit at the 25km mark was another harsh lesson in how my stomach couldn’t tolerate the same level of carbohydrate ingestion when running in hot conditions (it was about 28°C / 82.4°F at the time) as it can on the bike and in cooler temperatures (the run is almost always warmer than the bike in an IRONMAN).

In races thereafter, especially hotter ones, I would look to bank 90g of carb per hour on the bike, then scale back to 60g/hr on the run. I now know that if I can dismount my bike with 90g/hr of carbs banked, I will still run well (if I stay hydrated) with 60g/hr carbohydrate intake on the marathon.

I firmly believe we must have a different approach to nutrition on the bike versus the run because the stressors (such as mechanical gastrointestinal stress or heat stress as the day warms up) differ between each.

Do I profess to now being perfect when it comes to nutrition on race day? No chance. I still stuff up and I’m still learning and refining. We’re evolving beings and the beauty of endurance sport is we’re operating in constantly changing environments and race settings.

Survival of the fittest doesn’t just reference physical fitness, it also reflects the rewards on offer to those who are smart. Making a plan, practicing it, and executing on race day may not guarantee everything will go well. But it’s a huge step in the right direction.

After all, if you’re putting weeks and months of training into achieving a goal, what’s a few more hours spent at a computer crunching a fueling and hydration plan that accompanies you on your journey?

Further reading