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Steph Clutterbuck's scorecard

IRONMAN Vitoria-Gasteiz

Sunday 16th July, 2023

Within recommended ranges

Just outside recommended ranges

Significantly outside recommended ranges

  • 109g

    Carb per hour
  • 1,007mg

    Sodium per hour
  • 829ml

    Fluid per hour
  • 1,216mg/L

    Relative sodium concentration
  • 3.08mg/kg

    Caffeine per bodyweight
  • How Steph hit those numbers

    1L x PF Carb & Electrolyte Drink Mix + 1 x PH 1000 Packet
    1 x Bowl of Plain Rice
    1 x PF 30 Caffeine Gel
    1 x PF 30 Chews
    *** Try to avoid drinking too much at this point in the race!
    3 x PH Electrolyte Capsule
    1.5L x PF Carb & Electrolyte Drink Mix (8 Servings)
    5 x PF 30 Gel
    2 x PF 90 Gel
    3.5L x Plain water
    1L x PH 1000 (Drink Mix)
    10 x PH Electrolyte Capsule
    3 x PF 30 Gel
    1 x PF 30 Caffeine Gel
    2 x PF 90 Gel
    2.3L x Plain water

    How Steph's hydration and fueling went...

      • Four weeks after her impressive victory at IM 70.3 Staffordshire, Zwift Tri Academy member, Steph, secured her qualifying slot for the 2023 IRONMAN World Championships by winning in Vitoria-Gasteiz
      • Taking on the full-distance in Spain, she won the amateur race by more than 24 minutes and finished fourth among the professional women
      • Having previously suffered with sickness, nausea and being unable to finish full-distance races in the past, Steph was over the moon to crush her fuel and hydration strategy throughout this race, and finished feeling strong


      • As someone with a moderate-high sweat rate, and sweat sodium concentration (1,107mg/L), Steph knew that starting as hydrated as possible would be key to maintaining her 100% win record in 2023
      • Steph had her usual PH 1500 the night before the race, and created her own hybrid preloading drink to sip throughout race morning. By mixing two scoops of PF 60 Drink Mix and a PH 1000 tablet into a 1L (32oz) bottle, this gave her a relative sodium concentration of 1,000mg/L (mg/32oz), along with 30g of carbohydrate
      • Then, once out of the swim, (where Steph set a new course record, covering the 3.8k in a rapid 49:35!) and onto the bike, Steph began executing her rigorously tried-and-tested hydration plan
      • This was a culmination of some extensive planning by Steph, who carried two highly-concentrated bottles of PF 60 Drink Mix on her bike frame, and calculated how much plain water she needed to pick up from aid stations to dilute the mix to match her sweat sodium concentration
      • She did this with impressive accuracy, averaging ~1,118mg/L (mg/32oz) as she picked up four 750ml (24oz) bottles of plain water, and took some Electrolyte Capsules to ensure she didn’t over-dilute her fluids
      • Then onto the run, again, Steph’s well thought-out strategy involved running with a Soft Flask throughout the race to keep her fluid intake regular and controlled. She headed out of transition with two PH 1000 Packets in her flask, and once this was emptied she filled it twice more with plain water
      • Alongside the plain water, Steph also had Electrolyte Capsules taped to her gels so she could remember to take them regularly and avoid falling behind on her sodium intake
      • She repeated this strategy again in the second half of the run, picking up another Soft Flask of PH 1000 from the special needs aid station at 25k (15.5 miles)
      • Steph recalls the aid station was supposed to be at ~21k (13 miles), and the extra ~20 minutes of running really took it’s toll, and she was “begging for the aid station to arrive”
      • Overall, Steph can be proud of how accurately she executed her hydration strategy over such a long race, as she averaged an impressive ~829ml (27oz) per hour throughout the race. This fluid contained an average sodium concentration of ~1,216mg/L (mg/32oz), which is very close to her sweat sodium score, and so likely replaced a good proportion of the electrolytes she lost in her sweat


    Quick Carb Calculator Recommendation


    carb 30 mins before


    carb per hour during
      • The slightly later than usual race start (08:30) meant Steph could complete her carb-load without setting the alarm for the middle of the night like most triathlons. She had plenty of time to digest the bowl of rice she had for breakfast, giving her glycogen stores a final top off
      • Then, to instigate a rise in her readily available energy, Steph had a PF 30 Chew and a PF 30 Caffeine Gel within the final 20 minutes before the swim start
      • Steph has been training her gut for several months now, in an attempt to maximise the quantity of carb she can absorb comfortably during races, and reap the benefits associated with a high intake
      • On the bike she averaged an impressive ~118g per hour from eight servings of PF 60 Drink Mix, and a “gel bottle” made from PF 30 and PF 90 Gels with a splash of water. Similarly to her hydration strategy, the most vital piece to her fueling puzzle was to drink plenty of water, and help avoid any gastrointestinal upset from too much carbohydrate
      • During the run, Steph also stuck to her rigorous pre-race plan, by using her own nutrition throughout. Firstly by running out of T2 with a PF 90 Gel and two PF 30 Gels
      • She then sought to replace these at the halfway mark with her special needs pick up. Unfortunately, however, the biggest dip in her energy levels came shortly after halfway where this aid station was supposed to be, but instead was almost 4km later. By this point Steph was completely out of gels, and felt like she was “running on empty” by the time she picked up her second PF 90 and PF 30 Gels and they’d had time to take effect
      • After this brief slump, she started to come round again around 25 minutes later. Thankfully, Steph rated her GI comfort a perfect 10 (out of 10), experiencing no issues during or after the race. This shows how effective her gut training has been, and she should continue to practice this


      • Steph is now two-from-two with fuel and hydration strategies for 2023, nailing it this time over the full distance on her way to arguably the best result of her triathlon career
      • When asked post-race, Steph was adamant there was “truly nothing I’d change with my nutrition”, and even rated her race satisfaction a perfect 10 (out of 10)
      • This result actually qualified Steph for her professional racing licence, which is likely to be her next step once she’s raced the World Championships as an amateur in October

    Key info

    Steph Clutterbuck



    Overall Time
    Swim Time
    Bike Time
    Run Time
    Normalised power (Bike)

    Event information

    Full distance
    IRONMAN Vitoria-Gasteiz
    Vitoria-Gasteiz, Spain
    16th July, 2023
    Swim Distance
    3.8km / 2.4mi
    Bike Distance
    180.2km / 112.0mi
    Run Distance
    42.2km / 26.2mi
    Total Distance
    226.2km / 140.6mi

    Race conditions

    Weather Conditions
    No Rain
    Min Temp
    14°C / 57°F
    Max Temp
    23°C / 73°F
    Avg Temp
    19°C / 66°F

    Athlete feedback

    Race Satisfaction
    Hydration rating
    I could drink when I wanted to, so I wouldn't change a thing
    Energy levels
    Special needs on the run was later than planned, so I ran on empty for a few kms
    Toilet stops
    GI comfort
    Stomach was totally fine
    No cramping

    Steph's full stats

     Carbohydrate (g)Sodium (mg)Fluid (ml)Caffeine (mg)Relative sodium concentration (mg/L)
    Total intake9989,2507,6102001,216
    Per hour1091,00782922
    Bike and Run
    Total intake9389,2507,6101001,216
    Per hour1141,12192212
    Total intake5704,7504,25001,118
    Per hour1189868820
    Total intake3684,5003,3601001,339
    Per hour1071,31197929

    Data Confidence







    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).

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