• After having an Advanced Sweat Test with Phil Young on the Australian Gold Coast prior to IRONMAN Western Australia, Luke Henderson’s extreme sweat sodium losses became clear. Phil put Luke in touch with Precision Fuel & Hydration Founder Andy and Head of Customer Service James to talk through his strategy for his upcoming race
• Luke’s Advanced Sweat Test revealed he was losing 2,129mg of sodium per litre of sweat and he also conducted some sweat rate data collection, which showed he was losing over 1.5L/hr (51oz) in 20℃/68°F and even up to 3L/hr (101oz) in over 30℃/86°F. Luke had been using what would be considered a decent hydration and fueling strategy for many athletes, but Luke is at the higher end of the scale in terms of his sweat sodium and sweat volume losses, so he was only replacing a small proportion of those immense losses. This led to some significant issues in past races, suffering from severe cramping and hyponatremia
• After sitting down for a call with Andy and James, Luke went away with a more proactive hydration and fueling plan, which involved aiming to try to replace a greater proportion of his losses to avoid his previous issues
• Luke enjoyed an excellent performance in very hot conditions (28℃/82°F) in Western Australia, using his new and improved hydration and fueling strategy, finishing 4th in his age group (M35-39) with a time of 9 hours and 22 minutes

Hydration

• Luke preloaded with PH 1500 to make sure he started optimally hydrated, with a large reservoir of fluid to draw from and maximal blood volume. To prepare for his extremely high sodium losses, Luke chose to increase the strength of his preload by having two PH 1500 tablets in 700ml/24oz (relative sodium concentration of ~2143mg/L)
• Luke’s proactive hydration strategy involved drinking 9 x 700ml (24oz) bottles that contained 2 x PH 1500 tablets each, on the bike. Then on the run, he had a cup of water and a PH electrolyte capsule at most aid stations (6 aid stations each lap for 4 laps), a couple of 400ml/14oz bottles of PH 1500 each lap and on laps 3 and 4 picked up an additional two cups of Coca Cola
• In total, this meant Luke drank a massive ~12.5L/423oz over the whole race! Drinking out of only bottles on the bike gives us high data confidence in his numbers during this section; Luke drank ~1.4L/hr (47oz/hr) over the 4 hour 45 minute bike leg
• Drinking from aid station cups for the majority of the run means that Luke’s fluid intake estimates depend heavily on the volume in each cup and how much of each cup Luke actually drank. After discussing this with Luke in detail, we have estimated he drank ~150ml per cup (resulting in ~1.3L/hr overall and ~1.6L/hr on the run)
• Taking into account that a cup could have been a lower 100ml/3oz or up to 200ml/7oz, overall his fluid intake for the whole race could have been shifted by ~100ml/hr (3oz/hr) up or down. Even using the lowest estimate this still means his average intake was over ~1.2L/hr (41oz/hr), which is really impressive
• We know from previous sweat rate testing that Luke can easily lose over ~2L/hr (68oz/hr) in similar conditions, so it’s unlikely that he would have been overdrinking and exceeding his sweat losses, even if his intake was at the higher end of the estimated total (~1.9L/64oz per hour)
• Luke peed multiple times on the bike and once on the run, as would be expected in such a long race. Neither us or Luke feels he peed excessively which implies that he didn’t dramatically over-do his drinking
• Due to the heat, James also advised Luke to use cooling methods, specifically “pouring as much water on his head as possible on the bike and the run”. Luke did this during the race by also picking up cups of ice and pouring them on his head, neck and hands
• After talking with Andy and James, the biggest change to Luke’s strategy was being more aggressive with his sodium consumption to replace a greater proportion of his large losses. Luke consumed ~2,733mg sodium per hour, which meant the relative sodium concentration of his intake was ~2,035mg/L. This was consistent on the bike (~2,038mg/L) and on the run (~2,031mg/L). Considering Luke’s sweat sodium concentration is 2,129mg/L, this was an excellent intake to keep up with his losses and avoided a large deficit building up throughout the race
• As a result, Luke said “it was completely unbelievable! I didn’t experience any cramping at all” and was really happy with his hydration strategy, rating it 10 out of 10. On top of this, Luke said his recovery was a lot better than in previous races as he didn’t get his usual bad headache after the race

Fueling

Conclusions

• Luke was ”really happy” with the race, saying it “couldn’t have gone any better” as he beat his 9 hour 30 minute goal. He rated his race satisfaction as 8 out of 10, explaining the only thing lacking was that his run fitness wasn’t what he knows it can be, due to a slight injury in the build-up to the race
• In terms of hydration and fueling, Luke’s stuck to his demanding strategy well to keep on top of his extreme losses in very hot conditions
• After the race, Luke said “Andy and James’ help and ‘go ahead’ gave me the confidence to do what I thought I needed. Where I was previously only having less than half of what I needed during races, they gave me the confidence to change this, helping to solve my problems”