< Back to case studies

Tim Doran's scorecard

London Marathon

Sunday 3rd October, 2021

Within recommended ranges

Just outside recommended ranges

Significantly outside recommended ranges

  • 84g

    Carb per hour
  • 0mg

    Sodium per hour
  • 456ml

    Fluid per hour
  • 0mg/L

    Relative sodium concentration
  • 0mg

    Total caffeine
  • How Tim hit those numbers

    500ml x PH 1500 (Drink Mix)
    1 x PH Electrolyte Capsule
    1 x Bowl of porridge
    1 x Slice of bread with nutella
    1 x PF 30 Gel
    7 x PF 30 Gel
    1.3L x Plain water

    How Tim's hydration and fueling went...

      • After a recent 100km effort with a tough recovery, Tim went into the London Marathon planning for it to be a “good solid training run” to allow him to “recover quickly and start some winter mileage”. He planned to use the race as a “strict exercise to get the right fuelling and practice with gels every 20 minutes” as we had recommended to him after his last race
      • Despite not having the lead up he would have wanted, Tim had a solid race finishing in a time of 2 hours 51 minutes. He rated his race satisfaction as 10 out of 10 and he believes the “only reason” he ran as well as he did was “down to the gels”


      • Tim drank around ~456ml/hr (~15oz/hr) of fluid during the marathon by drinking roughly ~100ml/3oz of plain water every 2 miles. Considering the mild conditions, this is a decent amount which will most likely have adequately replaced part of what he was losing
      • He peed once at the end of mile 8 which is not excessive and therefore suggests that he did not overhydrate.Tim believes he drank enough as he didn’t get thirsty and commented that had he pushed earlier in the race he would have adjusted by taking on more fluid
      • Tim did not consume any sodium during the race and he could have benefitted somewhat from introducing some sodium into his strategy towards the end of his marathon. Fortunately having preloaded appropriately as per our recommendations and subsided this with a salt capsule too, he set himself up well to run ‘light’ on sodium and appeared to have no issues with doing this (no cramp reported for instance)


    Quick Carb Calculator Recommendation


    carb 30 mins before


    carb per hour during
      • Tim had an excellent pre-race intake. This consisted of him eating a breakfast high in carbs and low in fibre along with a PF 30 Gel at the start line to make sure his fuel stores were well topped up for the 9:30 start
      • As our Quick Carb Calculator recommends, we advise that for a race of this length and intensity that Tim consumes between 30-60g of carb per hour
      • Tim was able to consume an impressive ~84g/hr which was a total of ~240g over the course of the race, solely from PF 30 Gels. Due to the positive trend we see between carbohydrate intake and performance, as long as GI issues can be kept under control then this high intake can be seen as extremely positive. Tim specified that he experienced no GI issues (10/10)
      • For the last race of Tim’s that we analysed, Race to the Stones, he was able to consume ~62g/hr. Race to the Stones was longer therefore it’s not unusual for an intake towards the lower end of the 60-90g/hr recommendation to be seen. For this shorter event, pushing this carb intake up as per our recommendations and hitting ~84g/hr with a gel every 20 minutes allowed him to reach solid carb numbers. Learn more
      • He said that his “energy levels throughout the race were perfect” which is great to hear and not surprising considering the high levels of carb he was able to achieve for just under 3 hours. Tim agrees, believing he fuelled enough for this race but mentioned that he could have even managed a gel every 15 minutes


      • Despite ear-marking it as just a training run, Tim had a great race at the London Marathon after not having the lead up he would have liked. He held back in the first half but picked the pace up in the second half (he ran a 5-minute negative split!) and finished strongly
      • After listening to Andy’s previous advice, Tim stuck to a strict plan of consuming one gel every 20 minutes which was an excellent amount reaching ~84g/hr. This worked out well as Tim had ‘perfect’ energy levels during the race and alongside his large intake didn’t experience any GI issues. Well done Tim!

    Key info

    Tim Doran



    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
    Toilet stops
    Once at the end of mile 8
    GI comfort
    No cramping

    Tim's Thoughts

     For once everything went to plan. I knew lots of runners yesterday and some I beat that I really shouldn’t have, given the little amount of training. I think the only reason I ran as well as I did was down to the gels

    Tim's full stats

     Carbohydrate (g)Sodium (mg)Fluid (ml)Caffeine (mg)Relative sodium concentration (mg/L)
    Total intake24001,30000
    Per hour8404560

    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).

    Tim's recent case studies

    see all

    Related case studies

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