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Nick Harris-Fry's scorecard

London Marathon

Sunday 3rd October, 2021

Within recommended ranges

Just outside recommended ranges

Significantly outside recommended ranges

  • 50g

    Carb per hour
  • 219mg

    Sodium per hour
  • 353ml

    Fluid per hour
  • 621mg/L

    Relative sodium concentration
  • 56mg

    Total caffeine
  • How Nick hit those numbers

    500ml x PH 1000 (Tablet)
    500ml x Energy drink mix with caffeine (79g carb, 100mg caffeine)
    1 x Energy bar
    1 x White bagel with marmite
    200ml x Orange juice
    1 x Espresso
    2 x PH Electrolyte Capsule
    900ml x Plain water
    0.75 x Energy gel with caffeine (22g carb, 75mg caffeine)
    2.75 x Energy gel (40g carb)
    30ml x Energy drink (32.5g carb)

    How Nick's hydration and fueling went...

      • Nick had a strong run at the 2021 Virgin London Marathon in a time of 02:33:11. Despite wanting to run sub-2:30 as he had previously, he was satisfied with his performance and rated his race satisfaction a 7 out of 10 when balancing out missing his goal time and actual performance with the atmosphere and event as a whole
      • He did experience some GI issues during the event, rating his GI comfort just 5, and had to back off from his fueling around the ~29km point as a result. But, this subsided after relieving himself and he managed to continue and finish strongly
      • In this event, Nick mixed up his fueling strategy, opting to use almost solely energy gels for his carbs versus previously using liquid carbs in the form of an energy drink mix


      • Nick drank ~353ml/hr (~12oz/hr) across the race which he achieved by drinking a cup of water alongside each gel he consumed, plus two cups collected at other aid stations. Roughly this worked out as water drunk at every other aid station which given the milder conditions is a sensible strategy
      • Whilst on the lower side of an optimal fluid intake for a race of this duration, ~353ml/hr (~12oz/hr) would be considered pretty good given that drinking any more than this whilst running at this pace (3:38 min/km) can be difficult
      • Overall, when asked, Nick felt he hydrated well enough and reported never feeling thirsty which suggests he did a good job of keeping on top of his fluid losses
      • Alongside his fluid intake, Nick took two PH electrolyte capsules to tackle his sodium losses. He had also preloaded before the event with [PH1000]​​(https://www.precisionhydration.com/collections/1000s/). Whilst this isn’t completely in line with our recommendations (PH1500 mixed in 500ml/16oz plain water) it will have topped up his sodium and fluid levels enough to start him in a relatively good place hydration-wise (better than fluids devoid of electrolytes would have)
      • On the surface this is a somewhat low sodium intake but accounting for the lower than average volume of fluid Nick consumed, this equated to a relative sodium concentration of ~621mg/L which for a race of this duration and moderate conditions, is an adequate sodium intake for someone who isn’t too much of a salty, heavy sweater
      • Nick did report experiencing some twinges of muscle cramp in his inner thighs towards the end of the race but said this is something he experiences quite regularly and is an indication of fatigue and to not to speed up


    Quick Carb Calculator Recommendation


    carb 30 mins before


    carb per hour during
      • Nick consumed ~30 grams of carbohydrate in the final 30 minutes before the race by finishing his energy drink mix within this time period which will have helped him start the run with his energy levels topped up
      • On average, Nick consumed ~50 grams of carbohydrate per hour across the two and a half hour race. He met this number with the consumption of gels spread across the run starting with one taken at ~8-9km, one at 15-16km, a caffeinated gel ~24km and a further gel ~33km
      • Each gel was consumed roughly over a ~1.5km distance, drip feeding the gut with carbohydrate and striving for the maintenance of consistent energy levels
      • Across the course of the marathon Nick felt his energy levels were good, excluding ‘the usual marathon fatigue’, and rated them an 8. He also felt he fuelled enough but in hindsight could have spaced his earlier gels out more
      • Unfortunately, Nick’s ‘stomach went’ at around 29km so backed off his fueling until he had sought out an on-course portaloo and then slowly reintroduced some carb to carry him through the remainder of the run, getting down ¾ of a gel and a sip of on-course energy drink. He skipped his final planned gel as he felt OK energy-wise which given the earlier GI issues, and his good average carb intake, was a sensible decision
      • Greater spacing of Nick’s early gel intake may have reduced the severity or even occurrence of his GI issues but greater training of the gut within the race build up is likely to have been most beneficial


      • Nick had a good race at the London marathon. His sodium, fluid and carb intakes could have been dialled up marginally to optimally meet his needs but overall he adequately met all three which when running at this pace is an achievement in itself
      • Nick had a plan prior to the event, had tested this in some training and then proceeded to implement it on the day. Unfortunately, he did experience some gut discomfort, possibly as a result of mixing up his usual marathon strategy (liquid carbs) to gels

    Key info

    Nick Harris-Fry



    Overall Time

    Event information

    London Marathon
    London, England
    3rd October, 2021
    Total Distance
    42.2km / 26.2mi

    Race conditions

    Weather Conditions
    No Rain
    Min Temp
    12°C / 54°F
    Max Temp
    16°C / 61°F
    Avg Temp
    15°C / 59°F

    Athlete feedback

    Race Satisfaction
    Hydration rating
    Energy levels
    Excluding the usual marathon fatigue
    Toilet stops
    GI comfort
    My stomach went at 29km
    Twinges but not full-on cramps

    Nick's full stats

     Carbohydrate (g)Sodium (mg)Fluid (ml)Caffeine (mg)Relative sodium concentration (mg/L)
    Total intake12855990056621
    Per hour5021935322

    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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