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Luke Henderson's scorecard


Sunday 12th June, 2022

Within recommended ranges

Just outside recommended ranges

Significantly outside recommended ranges

  • 60g

    Carb per hour
  • 2,734mg

    Sodium per hour
  • 1,039ml

    Fluid per hour
  • 2,632mg/L

    Relative sodium concentration
  • 12.31mg/kg

    Caffeine per bodyweight
  • How Luke hit those numbers

    700ml x PH 1500 (Tablet)
    3 x Energy drink mix servings (21g carb each)
    1 x Coffee
    *** Tip: For sea swims, put a bottle of water at T1 to rinse your mouth out
    3.7L x PH 1500 (Tablets)
    2.3L x Plain water
    9 x Energy gel (40g carb)
    2 x Caffeine tablet (200mg caffeine)
    48 x PH Electrolyte Capsule
    3.6L x Plain water
    5 x Energy gel (25g carb)
    2 x Energy gel with caffeine (25g carb, 100mg caffeine)
    1 x Caffeine tablet (200mg caffeine)

    How Luke's hydration and fueling went...

      • As a triathlete who exhibits extreme sweat sodium and fluid losses, age grouper Luke Henderson pushed himself to the limit once again by competing in IRONMAN Cairns in hot conditions (~24℃/75°F)
      • After experiencing severe cramping and hyponatremia in the past, Luke has put together a more proactive hydration strategy with the help of the PF&H Team. Being more aggressive with his sodium and fluid replacement proved successful at IM Western Australia and IM 70.3 Melbourne, and going into another full distance race Luke looked to apply a similar strategy again
      • With good intentions, Luke made some changes on the run, opting to use more Electrolyte Capsules than previous races in replacement of the PH 1500 mixes he’s used before. Unfortunately, this adjustment proved not to be as effective and resulted in him not feeling great towards the end of the race
      • Nevertheless, Luke put in a decent performance that saw him finish 8th in the M35-39 age group with a solid time of 9 hours and 25 minutes


      • As has become the norm for Luke, he preloaded ahead of the race by drinking two PH 1500 (Tablets) in ~750ml/24oz of water; a drink with a relative sodium concentration of 2000mg/L. This strategy is to ensure that he starts well hydrated in preparation for the extremely high sweat losses he is going to incur
      • During the five-hour bike leg, Luke premixed six ~620ml/21oz bottles with three PH 1500 (Tablets) in each which he drank interchangeably with bottles of plain water picked up at aid stations
      • Luke drank a total of ~6.2L/210oz during the bike, made up of ~3.7L/125oz of concentrated PH 1500 and ~2.5L/85oz of plain water, which equated to ~1.2L/41oz of fluid per hour
      • This is a high fluid intake, though not necessarily for Luke who we know has a sweat rate of >1.5L/h (51oz/h), and has previous experience drinking ~1.4L/h (47oz/h) at Western Australia. Remarkably, he actually drank over one litre (32oz) less plain water than he had intended to drink but conditions were slightly cooler than anticipated
      • Luke consumed an average of ~2,703mg/h sodium on the bike which equates to a relative sodium concentration of ~2,202mg/L. This would be a very high concentration of sodium for most athletes but Luke falls at the extreme end of fluid and sodium losses, possessing a very high sweat sodium concentration of ~2,129mg/L. So, this was an effective strategy to replace his losses and is similar to the concentration he had overall at the shorter IM 70.3 Melbourne
      • The run leg was where Luke adjusted the plan he implemented at IM Western Australia. He stuck to his aggressive sodium and fluid targets, but this time Luke solely used Electrolyte Capsules alongside water he picked up instead of meeting his sodium needs using some flasks of PH 1500
      • Using this strategy, Luke worked on a rigid rotation of four Electrolyte Capsules every other aid station, consuming 48 Electrolyte Capsules in total. This equates to an intake of 12,000mg of sodium and 6,000mg of potassium, which he had intended to have alongside ~6L/203oz of water to make a relative sodium concentration of ~2000mg/L. However, Luke didn’t not drink this very high volume of fluid during the run leg, estimating that he actually drank closer to ~3.6L/122oz of plain water, which therefore made the relative sodium concentration of his intake an extremely concentrated ~3372mg/L
      • Around one hour into the run, Luke started to get a “tingling sensation” in his hands, face and upper body. Whether this is directly linked to him consuming such a large quantity of electrolyte capsules without a sufficiently high volume of water to match is not completely clear. However, taking on such an extreme concentrations of both sodium and potassium can certainly cause the body to take fluid from other areas to dilute blood plasma which can lead to severe issues (learn more)
      • Reflecting on the race, Luke knew what he had done wrong, saying “I was a little too confident that I had everything dialled in so I didn’t monitor things as closely during the race as I should have”. Considering he took on less fluid than he had planned, Luke should have reduced the number of Electrolyte Capsules he was consuming to keep the relative sodium and potassium concentration to a more reasonable level; this is especially important for someone like Luke who is working with such high intake quantities to avoid issues to his health as well as performance


    Quick Carb Calculator Recommendation


    carb 30 mins before


    carb per hour during
      • Ahead of the 7:48am race start, Luke had his usual race day fuel of three energy drink mix servings (~63g carb in total) to top up his glycogen stores. We would normally expect athletes to eat ‘real’ foods for breakfast before a race, especially one as long in duration as an IRONMAN, but this is Luke’s routine and it appears to be effective for him
      • As we have mentioned to Luke previously, he may want to trial having ~30g of carb, such as a gel, within 15 minutes of the swim to spike his blood glucose levels and spare glycogen stores for later in the race
      • Luke used energy gels during the race (nine with 45g of carb each on the bike and seven with 25g carb on the run) to reach the general carb recommendation of 60-90g/h for a race of this duration and intensity; consuming ~60g of carb per hour on average which is slightly less than we saw from him at Western Australia. Luke should target increasing his intake towards 90g/h, as our Fuel & Hydration Planner would advise, due to the positive trend between carb consumption and performance
      • His carbohydrate intake broke down into a higher ~78g/h on the bike and ~53g/h on the run. This ‘frontloading’ is a common trend to see in triathlon, but we are starting to see less of a drop off in top level athletes competing in full distance races (versus middle distance), and hitting over 90g/h on the bike leg to be able to sustain the lower intake on the run
      • Positively, Luke said his “energy levels felt pretty good” throughout the race and felt that his struggle on the run was largely a result of his hydration strategy
      • In terms of caffeine, Luke had a coffee before the race and then topped up with regular doses, having two caffeine tablets (200mg each) on the bike and one caffeine tablet on the run, alongside two 100mg caffeinated gels. This meant he had a high total caffeine dose of ~800mg caffeine, ~12.31mg/kg bodyweight, an intake above the guideline of between 3-6mg/kg
      • Such a large dose is most likely unnecessary as evidence suggests no added benefit of the additional caffeine above the recommendations and at such high doses, the negatives can outweigh the possible benefits. We would recommend that Luke sticks to the more sensible level of caffeine he took on board at both IM Western Australia and IM 70.3 Melbourne, which was still at the higher end of the guidelines (~6.63mg/kg)


      • Luke had a tough run at IM Cairns after taking on a very high sodium quantity which resulted in an immensely strong relative sodium concentration, a consequence of drinking less fluid than he had intended and not being flexible with his planned consumption of Electrolyte Capsules
      • He pushed through “not feeling great” to finish 8th, a brilliant performance in warm conditions all things considered
      • Going forward, Luke would benefit from being more flexible during the race so he can adjust his plan on the fly while being conscious of the quantities of fluid, sodium and carb he is taking on board. This is particularly important for an athlete like Luke, who is working with such large losses and intake volumes

    Key info

    Luke Henderson

    Sweat sodium concentration
    Sweat sodium classification
    Very High
    * determined by a PH Advanced Sweat Test


    Overall Time
    Swim Time
    Bike Time
    Run Time

    Event information

    Full distance
    IRONMAN Cairns
    Cairns, Queensland, Australia
    12th June, 2022
    Swim Distance
    3.8km / 2.4mi
    Bike Distance
    180.2km / 112.0mi
    Run Distance
    42.2km / 26.2mi
    Total Distance
    226.2km / 140.6mi
    Bike Elevation
    1,135m / 3,724ft

    Race conditions

    Weather Conditions
    No Rain
    Min Temp
    24°C / 75°F
    Max Temp
    26°C / 79°F
    Avg Temp
    25°C / 77°F

    Athlete feedback

    Toilet stops
    Once at the end of the bike
    GI comfort
    No cramping

    Luke's full stats

     Carbohydrate (g)Sodium (mg)Fluid (ml)Caffeine (mg)Relative sodium concentration (mg/L)
    Total intake56725,7469,7808002,632
    Per hour602,7341,03985
    Bike and Run
    Total intake56725,7469,7808002,632
    Per hour683,0771,16996
    Total intake39213,6056,1804002,202
    Per hour782,7031,22879
    Total intake17512,1413,6004003,372
    Per hour533,6421,080120

    Data Confidence







    There is an adequate level of accuracy in the data collected and the numbers reported. The athlete manages to recall what they ate and drank including most specifics (brands flavours quantities plausible estimations of volumes). However there are estimations made within the data which affect the overall confidence level in the data reported.

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