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Jen Aylward's scorecard

London Marathon

Sunday 3rd October, 2021

Within recommended ranges

Just outside recommended ranges

Significantly outside recommended ranges

  • 23g

    Carb per hour
  • 108mg

    Sodium per hour
  • 240ml

    Fluid per hour
  • 450mg/L

    Relative sodium concentration
  • 75mg

    Total caffeine
  • How Jen hit those numbers

    750ml x PH 1500 (Tablet)
    1 x Slice of toast with a poached egg
    1 x Bowl of porridge (with sultanas, apple and cranberry)
    1 x Cup of tea
    1tbsp x Protein powder
    2tbsp x Ground linseed
    500ml x Plain water
    500ml x Electrolyte tablet with caffeine (250mg sodium, 75mg caffeine)
    2 x Energy chew packet (48g carb)

    How Jen's hydration and fueling went...

      • Jen is a PH customer who completed the Virtual Virgin London Marathon. She had a great run clocking a sub-4 hour marathon on an undulating course. As a result she rated her satisfaction with the run a 10!
      • She was pleased to complete the marathon having experienced no major GI issues (rating GI comfort 9 out of 10) as this has previously been an area which has been a problem for her


      • Jen consumed an average of ~240ml/hr (~8oz/hr) across the marathon which she achieved by carrying 2 x 500ml/16oz bottles of fluid, one containing a caffeinated electrolyte tablet (75mg caffeine, ~240mg sodium) and one just plain water
      • This approach of one bottle containing electrolytes and one plain water is sensible and gives an athlete the option to drink what their body is craving
      • Jen’s fluid consumption is relatively low given the duration of the exercise period and in an ideal world could have benefitted from refilling her bottles at some stage during the run
      • It went in her favour that she preloaded effectively in the morning by drinking ~750ml/25oz of PH1500, along with some further fluid


    Quick Carb Calculator Recommendation


    carb 30 mins before


    carb per hour during
      • Jen didn’t start her virtual marathon run until 1PM in the afternoon allowing her to get a good intake of high carb foods during the morning which negated the need for a final pre-run carb intake. For some athletes eating too close to running can also predispose them to GI issues and with Jen’s history of this it was most likely a good idea to avoid it
      • During the marathon Jen used two packets of energy chews (providing a total of 96g of carb) to fuel her run. Per hour this worked out to be an average of ~23g/h which falls beneath the recommended carbohydrate guidelines for a run of this duration. Ideally, we would encourage an athlete to consume more than 30g/h and as close to 60g/h as possible (even above if it can be tolerated with no GI issues)
      • Jen reported that her energy levels felt good but that they started to dwindle around mile 24. At this point, she took her last energy chews but still experienced some hunger pangs. These are both signs which suggest she was under-doing her fueling
      • Jen’s more cautious fueling approach was likely a result of her previous experiences with GI issues in long runs/events and she commented ‘I could possibly have taken more fuel on board but felt comfortable with what I consumed


      • Overall, Jen had a great run clocking her first ever sub-4 hour marathon around a tough route
      • For future runs , upping her carb intake is something we would encourage Jen to continue to work on given the well regarded positive relationship between carbohydrate intake and performance. Nudging this upwards may also help prevent dips in energy and stave off feelings of hunger
      • But, this should be managed with how her GI system can cope. For athletes trying to increase their race intakes, extensive gut training needs to be undertaken

    Key info

    Jen Aylward



    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
    Toilet stops
    Comfort break at mile 16
    GI comfort
    No cramping

    Jen's Thoughts

     Sub 4 hour on an undulating course - boom

    Jen's full stats

     Carbohydrate (g)Sodium (mg)Fluid (ml)Caffeine (mg)Relative sodium concentration (mg/L)
    Total intake964501,00075450
    Per hour2310824018

    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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