< Back to case studies

Matthew Marquardt's scorecard


Friday 4th August, 2023

Within recommended ranges

Just outside recommended ranges

Significantly outside recommended ranges

  • 109g

    Carb per hour
  • 446mg

    Sodium per hour
  • 1,090ml

    Fluid per hour
  • 410mg/L

    Relative sodium concentration
  • 470mg

    Total caffeine
  • How Matthew hit those numbers

    500ml x PH 500 (Tablet)
    1 x 25g Carb Gel
    1 x Serving Tart Cherry Juice
    1 x Protein Shake
    1 x Whole Egg
    3 x Egg Whites
    1 x Cup of Oatmeal with Blueberries
    4 x Low Fibre Gluten Free Bread
    1tbsp x Almond Butter and Honey
    700ml x 2% Milk with protein powder
    1tbsp x Almond Butter and Jam
    1 x Serving of Sodium Bicarbonate
    0.5 x Caffeine Gel (25g carb)
    500ml x Isotonic Drink
    150ml x Starch Carb Drink
    1 x Serving Beetroot Powder
    1 x Energy gel (25g carb)
    0.5 x Energy gel with caffeine (25g carb, 100mg caffeine)
    *** Review technique if drinking much at this point!
    750ml x Plain water
    1.25L x Additional fluid in mixed drinks
    1 x Energy gel with caffeine (25g carb, 100mg caffeine)
    1 x Energy gel (40g carb)
    750ml x Lemon and Lime Energy Drink Mix (100g Carb)
    2 x Electrolyte Capsules (215mg Sodium)
    450ml x Plain water
    3 x Energy gel with caffeine (25g carb, 100mg caffeine)
    240ml x Energy drink (36g carb)
    210ml x Coca Cola Original
    1 x Electrolyte Capsules (215mg Sodium)

    How Matthew's hydration and fueling went...

      • Matthew delicately balances his time in full time education to become a medical doctor, with professional level triathlon training
      • After a fantastic performance at IRONMAN Texas 2023, claiming 3rd in his first race as a professional, Matthew was pleased to get a call up for the PTO US Open as a ‘wildcard’
      • Utilising an arsenal of sports fueling and hydration products which Matthew has extensively tested in training, he did well to finish 14th out of the 30 athletes who started the race


      • With an extensive knowledge of human physiology, Matthew understands that there’s a constant balance act in the body between electrolyte and fluid levels in the blood. In the hours ahead of the 4:15pm race-start, he drank several electrolyte drinks, including a PH 500 (Tablet) to induce some degree of hypervolemia (increased blood plasma volume) and start his race optimally hydrated
      • During the bike, Matthew decided to mainly drink a highly concentrated electrolyte and carbohydrate mix, which allowed him to spend the most time in an aerodynamic position drinking from a straw, without having to sit up too often
      • This resulted in him averaging just over 1.5L (48oz) of fluid per hour on the bike, before heading to the run course where he would rely on aid stations for cups of energy drink and water and drop to an average of ~844ml (30oz) per hour
      • We often see athletes ‘frontload’ their hydration during these middle distance races, it’s especially unsurprising on this occasion, where reports from the day suggested that it felt much warmer for the athletes on the ground than the ~22ºC (72ºF) temperature reading suggests
      • His fluid intake throughout the race was supplemented with electrolyte capsules to ensure he maintained a relative sodium concentration of ~410mg/L, which closely matched his sweat sodium concentration (655 mg/L) as determined by a Sweat Test


    Quick Carb Calculator Recommendation


    carb 30 mins before


    carb per hour during
      • With a later than usual start time for this race (4:15pm), Matthew extended his normal pre-race carb load beyond breakfast time, with mainly carbohydrate-rich foods which would bolster the glycogen stores in his muscles and liver
      • Matthew left no stone unturned in the immediate build up to the event, eating and drinking several supplements which he has found to be personally beneficial in training, including tart cherry juice, sodium bicarbonate and beetroot powder
      • Then, during the race, he consumed an average of ~109g of carb per hour, via a mixture of energy drinks and gels. Like his hydration, his hourly intake dropped slightly from bike (~121g) to run (~105g), however it still provided him with plenty of available energy to crush the 18km (11.2 mile) run course in just 1:04:28
      • The fact that Matthew could comfortably stomach no less than 9 different products while on the course is a testament to his rigorous experimentation within his training, with the goal of improving overall energy availability, whilst maintaining his gastrointestinal comfort


      • Matthew’s dedication to both medical studies and triathlon training is impressive, and he’s managing the balance well, finishing in the top half of a strong professional field
      • His understanding of physiology and meticulous experimentation in training have helped him develop his fuel & hydration strategy to a point where he feels comfortable adapting it for 70.3, full distance and hybrid distances like this race
      • This strategy allowed him to replace an adequate proportion of his sweat and sodium losses, avoid any dehydration related issues, and provide his working muscles with enough available energy to perform optimally

    Key info

    Matthew Marquardt

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


    Overall Time
    Swim Time
    Bike Time
    Run Time

    Event information

    Middle distance
    PTO US Open
    Milwaukee, USA
    4th August, 2023
    Swim Distance
    2.0km / 1.2mi
    Bike Distance
    80.0km / 49.7mi
    Run Distance
    18.0km / 11.2mi
    Total Distance
    100.0km / 62.1mi

    Race conditions

    Weather Conditions
    No Rain
    Min Temp
    18°C / 64°F
    Max Temp
    25°C / 77°F
    Avg Temp
    22°C / 72°F

    Athlete feedback

    Race Satisfaction
    Hydration rating
    During the race I was happy with my strategy, although beforehand I think I underestimated the temperatures a bit.
    Energy levels
    Overall I felt good considering the short build up to this race
    GI comfort
    Mild cramps that I could push through

    Matthew's Thoughts

     With only four days notice as a wildcard I'm happy with how my body performed on the day. I wasn't quite prepared for the absolute stampede at the start of the swim which meant I came out of the water further back than I would have liked, I'd change this for next time for sure.

    Matthew's full stats

     Carbohydrate (g)Sodium (mg)Fluid (ml)Caffeine (mg)Relative sodium concentration (mg/L)
    Total intake3641,4953,650470410
    Per hour1094461,090140
    Bike and Run
    Total intake3271,4653,650420401
    Per hour1155141,281147
    Total intake2151,0632,750100387
    Per hour1215961,54256
    Total intake112402900320447
    Per hour105377844300

    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.

    Matthew's recent case studies

    see all

    Related case studies

    Nail your next event with a FREE Fuel & Hydration Plan
    Get started