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Luke Henderson's scorecard

IRONMAN Western Australia

Sunday 5th December, 2021

Within recommended ranges

Just outside recommended ranges

Significantly outside recommended ranges

  • 65g

    Carb per hour
  • 2,733mg

    Sodium per hour
  • 1,343ml

    Fluid per hour
  • 2,035mg/L

    Relative sodium concentration
  • 6.63mg/kg

    Caffeine per bodyweight
  • How Luke hit those numbers

    700ml x PH 1500 (2 Tablets)
    3 x Energy drink mix servings (21g carb each)
    1 x Muffin
    1 x Coffee
    *** Review technique if drinking much at this point!
    9L x PH 1500 (Tablets)
    591ml x Plain water
    10 x Energy gel (22g carb)
    5 x Energy bar (40g carb)
    2 x Caffeine tablet (200mg caffeine)
    6L x PH 1500 (Tablets)
    10 x PH Electrolyte Capsule
    3L x Plain water
    4 x Energy gel (25g carb)
    300ml x Coca Cola Original

    How Luke's hydration and fueling went...

      • 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


      • 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


    Quick Carb Calculator Recommendation


    carb 30 mins before


    carb per hour during
      • Luke topped up his glycogen stores by having three energy drink mix servings and a muffin on the morning of the race. The race had an early start (6:50am) so Luke did well to get around ~1g carb per kilogram of bodyweight on board; the recommended pre-race carb intake is between 1-4g around 1-4 hours before the race
      • Luke could consider having a final ~30g of carbohydrate within the last 30 minutes before the swim in future races, which would hit his bloodstream quickly to spare some glycogen stores for later in the race
      • By eating a range of energy gels and bars, Luke consumed an average of ~65g of carb per hour over the race (this includes the time he was swimming). This is a solid amount to consume over a full distance IRONMAN and is within our Quick Carb Calculator's recommended 60-90g/hr
      • On the bike, Luke was able to consume ~95g/hr. This is an impressive intake, frontloading with over 90g/hr on the bike will have fueled him well going into the run where a tapering in consumption is expected, and he consumed a lower average intake of ~44g/hr. Unsurprisingly with his high carb intake, Luke said his energy levels were “always high” and rated them 10 out of 10
      • Luke experienced one slight GI issue on the run, but once he had been to the toilet was fine again. He didn’t think this impacted his race negatively as he rated his GI comfort on average as 9 out of 10
      • In terms of caffeine, Luke drank a coffee pre-race and had caffeine tablets and Coca Cola during the race. He had a total caffeine dose of ~424mg throughout the race, which equates to ~6.6mg/kg body weight and that’s at the top end of the recommended range (3-6mg/kg body weight) to enhance endurance performance


      • 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”

    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 Western Australia
    Busselton, Australia
    5th December, 2021
    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
    482m / 1,581ft
    Run Elevation
    184m / 604ft
    Total Elevation
    666m / 2,185ft

    Race conditions

    Weather Conditions
    Very Hot
    No Rain
    Min Temp
    16°C / 61°F
    Max Temp
    31°C / 88°F
    Avg Temp
    28°C / 82°F
    Feels like temp
    31°C / 88°F

    Athlete feedback

    Race Satisfaction
    Hydration rating
    I didn't feel like it caused any problems
    Energy levels
    Toilet stops
    Multiple small pees on the bike and once on the run
    GI comfort
    One slight issue on the run but it passed and then was fine
    No cramping

    Luke's full stats

     Carbohydrate (g)Sodium (mg)Fluid (ml)Caffeine (mg)Relative sodium concentration (mg/L)
    Total intake60725,62412,5914242,035
    Per hour652,7331,34345
    Bike and Run
    Total intake60725,62412,5914242,035
    Per hour743,1141,53052
    Total intake45314,0466,8914002,038
    Per hour952,9481,44684
    Total intake15311,5785,700242,031
    Per hour443,3421,6457

    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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