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Laura Siddall's scorecard

IRONMAN World Championships

Thursday 6th October, 2022

Within recommended ranges

Just outside recommended ranges

Significantly outside recommended ranges

  • 99g

    Carb per hour
  • 439mg

    Sodium per hour
  • 1,108ml

    Fluid per hour
  • 396mg/L

    Relative sodium concentration
  • 12.10mg/kg

    Caffeine per bodyweight
  • How Laura hit those numbers

    500ml x PH 1500 (Tablet)
    1 x White bread bagel with almond butter and jam
    0.5 x Banana
    1 x Boiled Egg
    1 x Cup of Coffee
    1 x PF 30 Energy Gel
    *** Try to avoid drinking too much at this point in the race!
    1.5L x PH 1500 (Tablets)
    2 x PH Electrolyte Capsule
    14 x PF 30 Energy Gel
    2 x PF 30 Caffeine Gel
    1 x PF 30 Energy Chews
    3.75L x Plain water
    500ml x PH 1500 (Tablets)
    2 x PH Electrolyte Capsule
    5 x PF 30 Energy Gel
    5 x PF 30 Caffeine Gel
    3.42L x Plain water
    480ml x Coca Cola Original

    How Laura's hydration and fueling went...

      • After enjoying a strong 2022 season that saw her finish 2nd at Challenge Puerto Varas, 7th at the IRONMAN World Championships in Utah and 4th at Challenge Roth, Laura was looking to replicate her good form in Hawaii
      • During the race, Laura arrived at the swim exit feeling “pretty chuffed” with the pack she came out as part of, although she ended up riding the full 180km bike leg almost completely solo. This gave Laura the opportunity to focus on nailing her pre-planned race nutrition strategy, which she'd worked on with guidance from Clinical Dietitian Claire Fudge at 4th Discipline
      • Off the bike and into the run with a transition time of 2:28, Laura ‘started conservatively’ before having to battle through the latter stages to the finish line with a run time of 3:17:34. In doing so, she claimed her second top-10 spot at an IRONMAN World Championships for the year with a time of 9:07:49


      • Laura followed her usual pre-race plan by pre-loading with PH 1500 (Tablets) the night before and the morning of her race, to ensure she started optimally hydrated, with a topped up blood plasma volume
      • Laura had prepared bottles of PH 1500 (Tablets) to drink on the bike, alongside water that she could pick up from aid stations. As well as drinking from these water bottles, she dumped some on her head to keep cool as the temperatures soared
      • Her average fluid intake on the bike came to ~1.26L (42oz) per hour, while maintaining a relative sodium concentration of ~458mg/L (mg/32oz) with the use of Electrolyte Capsules
      • Coming off the bike in 12th place, Laura had a quick transition and got back out on course, where she would drink cups of water and Coca Cola from each aid station, as well as utilise the six pro aid station bottles she had access to
      • As you can see in this video on Laura’s Instagram page, the intake of fluid from aid stations is hard to approximate when running at such high speeds. We’ve worked out that she’d have had around ~4.1L (139oz) total fluid on the run, which breaks down into ~1.25L (42oz) per hour
      • Her intake of ~4.1L (139oz) in Hawaii represents a ~48% increase on what she drank during the run at Challenge Roth. This can largely be attributed to the more extreme temperatures in Kona causing Laura to have a higher sweat rate, which in turn meant that she increased her intake to account for her higher fluid losses.
      • This is more than we'd typically expect to see an athlete drink during the marathon of an IRONMAN but it's worth re-emphasising that the heat that the athletes were exposed to on race day was extreme (and Laura's intake wasn't dissimilar to what fellow top-10 finishers like Leon Chevalier and Fenella Langridge drank).
      • She boosted her electrolyte intake using Electrolyte Capsules, as well as a small 200ml (7oz) flask containing a PH 1500 (Tablet). This allowed her to achieve a relative sodium concentration of ~305mg/L (mg/32oz) for this leg of the race as she fought hard to claim 10th position overall
      • Laura knows that she has a low sweat sodium concentration of 614mg/L (mg/32oz) after taking a Sweat Test at 4th Discipline
      • This means that despite achieving an average relative sodium concentration of ~396mg/L (mg/32oz) for the race, which would be potentially problematic for a lot of athletes, she was happy to report absolutely no cramping and an 8 (out of 10) rating for her hydration on the day


    Quick Carb Calculator Recommendation


    carb 30 mins before


    carb per hour during
      • Laura carb-loaded with carbohydrate rich foods in the build up to her race, culminating in a breakfast which included a white bread bagel and half a banana. She also had a PF 30 Gel during the final 15 minutes before the start of the race, so that not only were her glycogen stores topped up, so was her blood glucose - delaying the need to access her stored energy as quickly
      • On the bike she fueled using fourteen PF 30 Gels, two PF 30 Caffeine Gels and one PF 30 Chew, which provided over 500 grams of carbohydrate during her ride, working out at ~108g of carb per hour
      • She maintained this strong level of fueling on the run course, alternating between PF 30 Gels and PF 30 Caffeine Gels - as well as getting some carb from aid station energy drinks. This gave her an average intake of ~107g/h while running and ~99g/h on average for the whole race (34% higher than her intake at Roth)
      • This is another example of an athlete being able to exceed the 90g/h that was traditionally thought to be a ‘ceiling’. There’s a host of emerging evidence to disprove this theory, and Laura’s intake goes some way to supporting this notion too, reporting a solid 7 (out of 10) for energy levels across the race with zero GI distress
      • With a total of ~738mg across the race, Laura would have also felt the physical and mental benefits associated with caffeine. This intake is more than double the general recommendation for caffeine intake during endurance activity of 3-6 milligrams per kilogram of bodyweight, putting her at ~12.1mg/kg. This is similar to what we saw when analysing her intake from Challenge Roth (11.31mg/kg). As someone with a clearly high tolerance for caffeine, it isn’t necessarily something she needs to change whilst spreading the intake across a prolonged effort


      • Laura has now competed in four IRONMAN World Championships hosted in Kona, and the 42-year-old is only getting quicker with age, beating her previous best split on the bike course by a significant 8 minutes this time around
      • Laura executed a very effective fuel and hydration strategy, with plenty of energy to get around the course, and appropriate volumes of fluid and electrolyte to avoid feeling the effects of dehydration. This helped her avoid joining the high DNF rate on race day despite the harsh environmental conditions, with nearly one-third of the starting female pros failing to make it to the finish chute
      • She reported her race satisfaction as an 8 (out of 10), whilst identifying some areas that she’d hoped could have gone better to reflect the hard work she’s been putting in during training. Overall, she was extremely happy with securing a top-ten in Kona, something which she said she “never thought would happen”

    Key info

    Laura Siddall

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


    Overall Time
    Swim Time
    Bike Time
    Run Time

    Event information

    Full distance
    IRONMAN World Championships
    Kona, Hawaii
    6th October, 2022
    Swim Distance
    3.9km / 2.4mi
    Bike Distance
    180.2km / 112.0mi
    Run Distance
    42.2km / 26.2mi
    Total Distance
    226.2km / 140.6mi
    Bike Elevation
    1,772m / 5,814ft
    Run Elevation
    307m / 1,007ft
    Total Elevation
    2,079m / 6,821ft

    Race conditions

    Weather Conditions
    Very Hot and Humid
    No Rain
    Min Temp
    24°C / 75°F
    Max Temp
    29°C / 84°F
    Avg Temp
    27°C / 81°F

    Athlete feedback

    Race Satisfaction
    Hydration rating
    Energy levels
    Pretty good levels all day - although I felt a bit up and down during the run
    Toilet stops
    Just once slightly on the run
    GI comfort
    No cramping

    Laura's Thoughts

     Pretty much went to plan I think!

    Laura's full stats

     Carbohydrate (g)Sodium (mg)Fluid (ml)Caffeine (mg)Relative sodium concentration (mg/L)
    Total intake8984,00010,100738396
    Per hour994391,10881
    Bike and Run
    Total intake8684,00010,100738396
    Per hour1084971,25592
    Total intake5152,7506,000200458
    Per hour1085771,25942
    Total intake3531,2504,100538305
    Per hour1073811,249164

    Data Confidence







    There is low confidence in the accuracy of the numbers reported. The intake reflects a rough guide to what an athlete consumed but quantities volumes or specific brands might be unknown. It is a loose insight into what the athlete did but the room for error is high-to-very high. This level of confidence most likely reflects the nature of the event (for example an ultramarathon 24 hour or multi-stage event).

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