Ant Gritton
Precision Fuel & Hydration IRONMAN 70.3® World Championship
MarbellaTop 50, M35-39Ant's headline numbers
Ant's strategy
Fueling
T - 1-4hrs: Ate a carb rich meal (Low in fat & fibre)
T - 15mins: Took in a final dose of carb
"I felt great all day, had plenty of energy and had no issues here. "
Ant followed an aggressive fueling strategy on the bike, taking in ~142g of carbohydrate per hour from a combination of PF 300 Flow Gel and two PF 30 Caffeine Gels. By front-loading his carb intake during the bike leg, he ensured he began the run with high energy availability.
He adjusted his intake to ~75g/h whilst running by using a mix of caffeinated and non-caffeinated PF 30 Gels. Because running often reduces gut comfort and blood flow to the GI tract, this slightly lower, yet still decent, rate of carb intake helped him maintain energy delivery without risking GI distress. His consistent pacing throughout the half marathon suggests the strategy worked effectively, with steady energy availability all the way to the finish.
Hydration
Taking on board an appropriate amount of fluid and sodium is essential to maintaining blood volume and supporting the cardiovascular effort needed to perform on race day.
Whilst the absolute amount of sodium and fluid consumed per hour is important, it’s critical to consider these in relation to each other. This is known as 'relative sodium concentration' and it’s expressed in milligrams per litre (mg/L). How much sodium you’re taking in per litre of fluid is more important than the absolute amount taken in per hour.
Ant1351mg/L
Ant has been Sweat Tested to dial in his hydration plan
Sweat sodium concentration (mg/L) is largely genetically determined and remains relatively stable. Knowing how salty your sweat is enables you to replace a good proportion of your sweat losses, which can range from 200-2,000mg/L.
Given Ant's losses are High (1,351mg/L), nailing his hydration strategy becomes especially crucial when it's hot and/or humid.
Learn moreT - 60mins: Drank ~500ml of strong electrolyte drink
"Hydration was mostly good until the final lap of the run. I didn’t drink as much at this point as everything started hurting! But it didn't affect my performance too drastically."
Ant consumed just over ~1L of fluid per hour on the bike, starting with 750ml of PH 1500 (Tablets) on his bike frame before picking up two bottles of PH 1000 at on-course aid stations. The combined relative sodium concentration of these drinks was within ~100mg/L of his sweat sodium concentration, allowing him to effectively replace his sodium losses and avoid dehydration-related symptoms. This also supports fluid retention and blood volume maintenance, which are crucial for effective thermoregulation. On the run, his fluid intake decreased to ~600ml/h, and while this was a reduced rate of intake compared to the bike, it was likely still enough to support hydration status. He began with a soft flask of PH 1500 and collected additional cups of PH 1000 on the course.
With an exceptionally high sweat rate, Ant relied on a well-practised hydration strategy to minimise fluid loss during the race. Pre- and post-race body mass measurements showed a 2.9% reduction; still within the range where performance can begin to be negatively affected. So, slightly increasing his intake in similar future race conditions may help reduce total fluid loss even further and account for his extra high losses.
Caffeine
Beyond the Three Levers of Performance (carb, sodium and fluid), caffeine is one of only a few substances that is proven to improve performance for most endurance athletes as it can help stave off mental and physical fatigue.
T - 0-4hrs: Had a final hit of caffeine
Ant used caffeine strategically, spreading his intake across the race rather than opting for one large dose. His total race-day caffeine intake reached ~6.67 mg/kg, which sits at the upper end of evidence-based recommendations, but it was clearly well tolerated by Ant. His staggered approach supports sustained central nervous system stimulation and helps maintain pace as fatigue accumulates, working well to support his performance on the day.
How Ant hit his numbers
Here's everything that Ant ate and drank on the day...
Final thoughts
“Everything was going so well until about 6/7km into the run - I’m just not conditioned enough for supershoes! My ankles started to hurt, then hips and back and it was a real slog to finish with a big breakdown in form. It wasn’t horrific and I could still enjoy the finish (probably due to having fueled so well and plenty of caffeine). ”
“Ant followed a fuel and hydration plan that closely matched his needs, with a high-carb intake on the bike, and a sodium concentration aligned with his own sweat losses. He avoided GI issues, maintained steady energy, and felt strong through the final kilometres of the run. Finishing 42nd left him satisfied with both the performance and the process: the plan was executed exactly as intended, and the result reflected it!”
PF&HAnt's full stats
Data Confidence
We rate each of our case studies from 1-5 based on the level of accuracy, and our confidence in the data.
There is good confidence in the accuracy of the data reported. An athlete feels that the numbers closely reflect what they consumed despite a couple of estimations which may carry some degree of error. The majority of what was consumed is recorded to a high level of specificity (most volumes are known through the use of bottles brands quantities flavours). The numbers are very plausible and align with previous data recordings (if an athlete has collected data previously).