GU

Fuel Planner

Build your race-day fuelling plan

Carbohydrate, sodium and fluid targets per hour, a timeline of what to take and when, and the exact product list — for South African events, in grams, millilitres and Rand.

Your day

Sport

Marathon to ultra on tar

Event

0:30 to 14:00. Be honest, not optimistic.

Sweat rate

Damp kit, some salt marks

Long, hot and relentlessly hilly. Fuelling errors compound after seven hours.

Comrades Marathon · 10:00

  • 85 g

    Carbohydrate per hour

  • 550 mg

    Sodium per hour

  • 700 ml

    Fluid per hour · 1 bottle

  • 929 g

    Total carbohydrate carried

How we got there

Carbohydrate: 85 g per hour

Over 6 hours: 85 g/h, the top of what a trained gut absorbs comfortably. Over 10:00 that is roughly 850 g of carbohydrate — this plan delivers 929 g.

Fluid and sodium: 700 ml and 550 mg per hour

Medium sweat rate: start at 700 ml of fluid per hour. On a day longer than six hours, drink to a schedule — thirst lags behind losses. Sweat sodium is assumed at 800 mg per litre for this sweat rate, which puts the target near 550 mg/h. That works out to about 1 bottle an hour, and the plan carries 5460 mg of sodium in total.

Why these products, in this order

We start with a gel five minutes before the gun, then feed roughly every 20 to 30 minutes so the gut never has to process a large bolus at once.

Caffeine: 0 mg, all after 4:30

This effort is short enough that caffeine timing barely matters — take it before the start if you normally do.

Practise it before race day

Run or ride at least two long sessions using exactly this plan, at race pace, with the same flavours. Gut tolerance is trainable, and race day is the wrong place to discover a flavour you can't face at hour six.

Timeline — what to take and when

  1. 0:00StartEnergy Gel22 g · 60 mg
  2. 0:12Settle inChews23 g · 40 mg
  3. 0:24Settle inChews23 g · 40 mg
  4. 0:36Settle inChews23 g · 40 mg
  5. 0:48Settle inHydration Tab1 g · 320 mg
  6. 1:10Settle inChews23 g · 40 mg
  7. 1:20Settle inChews23 g · 40 mg
  8. 1:30Settle inChews23 g · 40 mg
  9. 1:40Settle inChews23 g · 40 mg
  10. 1:50Settle inHydration Tab1 g · 320 mg
  11. 2:10Settle inChews23 g · 40 mg
  12. 2:20Settle inChews23 g · 40 mg
  13. 2:30Settle inChews23 g · 40 mg
  14. 2:40Settle inChews23 g · 40 mg
  15. 2:50Settle inHydration Tab1 g · 320 mg
  16. 3:10Settle inChews23 g · 40 mg
  17. 3:20Settle inChewsElectrolyte Capsule23 g · 360 mg
  18. 3:30MiddleChews23 g · 40 mg
  19. 3:40MiddleChews23 g · 40 mg
  20. 3:50MiddleHydration Tab1 g · 320 mg
  21. 4:10MiddleChews23 g · 40 mg
  22. 4:20MiddleChews23 g · 40 mg
  23. 4:30MiddleChews23 g · 40 mg
  24. 4:40MiddleChews23 g · 40 mg
  25. 4:50MiddleHydration Tab1 g · 320 mg
  26. 5:10MiddleChews23 g · 40 mg
  27. 5:20MiddleChews23 g · 40 mg
  28. 5:30MiddleChews23 g · 40 mg
  29. 5:40MiddleChews23 g · 40 mg
  30. 5:50MiddleHydration Tab1 g · 320 mg
  31. 6:10MiddleChews23 g · 40 mg
  32. 6:20MiddleChews23 g · 40 mg
  33. 6:30MiddleChews23 g · 40 mg
  34. 6:40MiddleChewsElectrolyte Capsule23 g · 360 mg
  35. 6:50MiddleHydration Tab1 g · 320 mg
  36. 7:10The hard partChews23 g · 40 mg
  37. 7:20The hard partChews23 g · 40 mg
  38. 7:30The hard partChews23 g · 40 mg
  39. 7:40The hard partChews23 g · 40 mg
  40. 7:50The hard partHydration Tab1 g · 320 mg
  41. 8:10The hard partChews23 g · 40 mg
  42. 8:20The hard partChews23 g · 40 mg
  43. 8:30The hard partChews23 g · 40 mg
  44. 8:40The hard partChews23 g · 40 mg
  45. 8:50The hard partHydration Tab1 g · 320 mg
  46. 9:10Bring it homeChews23 g · 40 mg
  47. 9:20Bring it homeChews23 g · 40 mg
  48. 9:30Bring it homeChews23 g · 40 mg
  49. 9:40Bring it homeChews23 g · 40 mg
  50. 9:50Bring it homeHydration Tab1 g · 320 mg

Totals across the plan: 929 g carbohydrate, 5460 mg sodium, 0 mg caffeine.

Your product list

  • Hydration Drink Tabs

    Hydration Drink Tabs

    2 × 8 Tube Box · plan needs 10 tubes

    One tab per 500 ml bottle covers 700 ml/h of fluid.

    R1 998
  • Energy Chews

    Energy Chews

    2 × 12 Pack Box · plan needs 20 sleeves

    Something to chew when gels get boring; a sleeve is two feeds.

    R1 198
  • Roctane Electrolyte Capsules

    Roctane Electrolyte Capsules

    1 × 50 Capsules · plan needs 2 capsules

    Tops your sodium up to target without adding more sweetness.

    R250
  • GU Energy Gel

    GU Energy Gel

    1 × Single Gel · plan needs 1 gel

    Your backbone fuel — 22 g of carbohydrate you can take one-handed.

    R39

Plan totalR3 485

Free delivery on orders over R500. Adjust flavours in the cart before checkout.

This planner gives general guidance based on published sports nutrition ranges. It is not individual nutrition or medical advice. If you are managing a medical condition, are pregnant, or have a history of gut trouble in racing, speak to a registered dietitian or your doctor before changing your fuelling. Always rehearse a plan in training first.

Want the reasoning in long form? Read How to fuel Comrades and Training your gut to handle carbs.