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How to Use Chat GPT for Race Planning

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January 06, 2026•4 min read

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How to Use Chat GPT for Race Planning

Technology is a tool we can use to our advantage. I've done this for quite a few races so I thought I might share with you guys how I race plan for fueling and hydration strategies. Here is the prompt I gave ChatGPT to help plan my hydration strategy for Mountain Mist:

I am making a hydration plan for the Mountain Mist 50K. Here is my last year splits to aid stations:

Aid station 1: 4.3 mi at 32 min

AS 2: 11.4 mi at 1:30

AS 3: 14 mi at 1:49

AS 4: 20 mi at 2:51

AS 5: 25 mi at 3:47

AS 6: 29.5 mi at 4:39

Finish: 31.5 mi at 4:53

I plan to run the course 5% faster overall.

I plan to carry two 20 oz soft flasks and drink on course water and sports drink.

My sweat rate is high losing 3-4 lb/hr typically in this event.

I need you to adjust my splits to meet my goal of 5% faster and also tell me exactly how much water I need between aid stations. I already have a personalized electrolyte and fuel plan so I won’t need that.

CHATGPT's RESPONSE:

Perfect — you gave exactly the data needed. I’ll keep thisstrictly pacing + water volumeand assume yourfuel/electrolytes are already solved.

Below is a5% faster projection, thenexact fluid targets between aid stationsbased on your known sweat loss.

1️⃣ Adjusted Splits (5% Faster Overall)

Start → AS1 (4.3 mi): 0:30
Start → AS2 (11.4 mi): 1:26
Start → AS3 (14.0 mi): 1:44
Start → AS4 (20.0 mi): 2:43
Start → AS5 (25.0 mi): 3:35
Start → AS6 (29.5 mi): 4:25
Finish (31.5 mi): 4:38

2️⃣ Time Between Aid Stations (Goal Pace)

Start → AS1: 0.50 hr
AS1 → AS2: 0.93 hr
AS2 → AS3: 0.30 hr
AS3 → AS4: 0.98 hr
AS4 → AS5: 0.87 hr
AS5 → AS6: 0.83 hr
AS6 → Finish: 0.22 hr

3️⃣ Sweat Rate → Fluid Requirement

You lose 3–4 lb/hr
• 1 lb ≈ 16 oz
• Sweat loss = 48–64 oz/hr

For Mountain Mist terrain + heat history, I’d plan ~55–60 oz/hr intake
(This is aggressive but appropriate for you given prior loss data.)

I’ll calculate using 56 oz/hr as the target.

4️⃣ Exact Water Needed Between Aid Stations

Start → AS1 (0.50 hr)

• 56 × 0.50 = 28 oz

➡️ Drink ~¾ of one 20 oz flask + sips from course

AS1 → AS2 (0.93 hr)

• 56 × 0.93 = 52 oz

➡️ Both flasks full (40 oz) + ~12 oz on course

AS2 → AS3 (0.30 hr)

• 56 × 0.30 = 17 oz

➡️ One flask partially full (~20 oz max)

AS3 → AS4 (0.98 hr)

(One of the hardest segments)
• 56 × 0.98 = 55 oz

➡️ Both flasks full + ~15 oz on course

AS4 → AS5 (0.87 hr)

• 56 × 0.87 = 49 oz

➡️ Both flasks full, finish ~½ flask

AS5 → AS6 (0.83 hr)

• 56 × 0.83 = 46 oz

➡️ Both flasks ~¾ full

AS6 → Finish (0.22 hr)

• 56 × 0.22 = 12 oz

➡️ One small top-off or handheld sip strategy

5️⃣ Carry Strategy (2 × 20 oz Soft Flasks)

Key rule:

Never leave an aid station with less than the next segment’s minimum requirement in your vest.

Refill guidance

Long segments (>50 min): leave full
Short segments (<30 min): partial refill saves time
Always top off before AS3 and AS4

6️⃣ Reality Check (Important)

Even at 56 oz/hr, you’ll still finish slightly negative on fluid balance — which is normal and acceptable for a 50K. Trying to replace 100% of a 4 lb/hr loss would be a GI disaster.

This plan keeps you:

Well ahead of dehydration curve
GI-safe
Aggressive enough for your physiology

If you want, next steps I can:

Convert this into a laminated wrist card
Build a vest-loading checklist per aid station
Adjust for forecasted temp / humidity
Model worst-case heat scenario (+10°F)

Back to me and not ChatGPT....

Isn't that freaking cool???? I have gone so far as to continuing to ask it to make me a card and adding in a fueling plan and other variables. But for simply getting thins right between aid stations I really think this is a game changer and something that everyone could use to have a better race execution and plan!

Hope this helps.

-Dylan

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