Races›Ultra 100K

Never Summer 100km & 60km

Race-specific weather data and nutrition strategy for Never Summer 100km & 60km in Walden, CO, US.

RunningUltra 100K (62.1 mi)Registration Open
LocationWalden, CO, US
Date
July 24, 2026
Register on RunSignUpBuild Your Fueling PlanOfficial website
Race Location40.73°, -106.28°
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Race-Day Conditions

Moderate Heat Risk
Temperature
80°F

75–85°F range

Humidity
46%

32–58% range

5-year average via Open-Meteo. 80% of race days fall within the range shown. Updated Mar 30, 2026.

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Moderate heat risk

Temperatures may reach 85°F. Plan for 10-15% higher sweat rates than cool conditions. Ensure adequate sodium intake (600-900 mg/hr) and consider pre-cooling strategies.

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Gut fatigue management

For races lasting 6+ hours, gut absorption efficiency decreases over time. Plan to reduce carb intake by 10-15% after hour 6 and shift toward easily digestible sources like gels and simple sugars.

Sample Ultra 100K Nutrition Plan

Based on a 155 lb runner finishing in ~14 hours. Your plan will differ based on body weight, experience, and conditions.

HourCarbsFluidSodiumExample
Hours 1–3180g57oz1400mgGels + sports drink
Hours 4–7240g75oz2000mgMix of gels, chews, real food
Hours 8–10150g53oz1500mgBroth, PB sandwich, gels
Hours 11–14180g62oz1600mgWhatever stays down + cola
Total750g247oz6500mg

These are general estimates. Get your personalized plan for this race →

What to Expect at Never Summer 100km & 60km

Never Summer 100km & 60km is a Ultra 100K (62.1 mi) ultra 100k held in Walden, CO, US. Based on 5 years of historical weather data, athletes can expect median race-day temperatures around 80°F.

Temperatures at Never Summer 100km & 60km typically range from 75°F to 85°F. This puts the race squarely in high heat risk territory. Sweat rates can increase 15–25% in these conditions, meaning both fluid and sodium demands rise significantly. Athletes should plan for increased hydration, consider pre-cooling strategies, and expect pace adjustments — even well-trained runners slow 1–3% per 10°F above 60°F.

Ultra-distance racing demands a flexible nutrition strategy. Gut absorption efficiency declines over many hours, so plan for variety — alternating between gels, chews, real food, and liquids helps prevent flavor fatigue and GI rebellion. Many ultra runners find that what works at hour 3 is intolerable by hour 10. Build your plan with options, not rigid prescriptions.

We do our best to keep race details accurate and up to date, but things can change and occasionally we simply get something wrong.

Always check the official website for the most complete and current information.

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Fueling and hydration suggestions are based on published sports science research including ACSM position stands, ISSN guidelines, and peer-reviewed work by Jeukendrup, Sawka, and others. This is not medical or dietary advice — individual needs vary. Always test your nutrition strategy in training before race day.

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Frequently Asked Questions

What should I eat during the race?
Your nutrition plan depends on your body weight, experience level, and race-day conditions. Use our free calculator to get a personalized, hour-by-hour fueling plan with specific carb, fluid, and sodium targets for this Ultra 100K.
What is the typical race-day weather?
Based on 5 years of historical data, race-day temperatures at Walden, CO typically range from 75°F to 85°F (median 80°F). Humidity ranges from 32% to 58%.
How much water should I drink?
Fluid needs vary based on your sweat rate, body weight, and race-day temperature. A typical range is 400-800 mL per hour, but hotter conditions at Walden, CO may require more. Our calculator provides personalized fluid targets adjusted for the expected weather.
How many calories do I need?
Rather than replacing all calories burned, focus on carbohydrate intake — the primary fuel for endurance performance. Target 30-50% of caloric expenditure through carbs. Our calculator computes the exact hourly targets based on your Ultra 100K pace and body weight.
When should I start fueling?
Begin fueling within the first 30-45 minutes. Start at about 70% of your target intake and ramp up to full by hour 2. This gives your gut time to adjust. Starting too late makes it nearly impossible to catch up on carbs and fluids.
Source: runsignup_apiView sourceVerified: Mar 30, 2026Confidence: 95%