Master the Chihuahua by UTMB® 38K: Complete Training & Race Strategy Guide
A comprehensive preparation guide for conquering this 38km mountain ultra. Learn proven training methods, elevation strategies, and race-day tactics from experienced ultrarunners.
38.0km
International
Understanding the Chihuahua by UTMB® 38K Course
The Chihuahua by UTMB® 38K is a challenging mountain ultra that demands serious respect. As part of the UTMB® family of races, this event combines technical trail running with significant elevation demands across a 38-kilometer distance. The mountain terrain requires a different approach than road ultras—you're navigating technical footing, variable conditions, and sustained climbing that will test both your aerobic capacity and mental resilience. The race takes place in a region with distinct seasonal characteristics, so understanding the course profile is critical for effective training. Unlike road ultras where pacing is relatively predictable, mountain terrain introduces variability in pace, recovery between climbs, and the mental challenge of technical descents when fatigued. For specific details about elevation gain, loss, maximum altitude, and exact course routing, check the official Chihuahua by UTMB® website at https://chihuahua.utmb.world, as course variations can occur year to year.
Mountain terrain demands different training than road ultras
Technical footwork and climbing will slow your pace significantly
Mental fatigue from technical terrain is as important as physical preparation
Course familiarization is critical—study the exact route if possible
UTMB® races are known for challenging alpine conditions
Chihuahua by UTMB® 38K Training Plan Overview
A 24-week training plan designed specifically for the demands of Chihuahua by UTMB® 38K.
Base Building Phase
8 weeks
Establish aerobic foundation with long runs on varied terrain, introduce hill repeats and vertical gain work, build weekly mileage progressively to avoid injury
Peak: 80km/week
Specific Strength & Climbing Phase
8 weeks
Emphasize climbing workouts on steep terrain, develop power hiking technique, introduce back-to-back long runs on mountains, improve efficiency on technical descents
Peak: 100km/week
Peak & Race Simulation Phase
6 weeks
Execute race-paced mountain runs, practice nutrition and pacing strategy on course-similar terrain, introduce altitude exposure if possible, maintain intensity while managing fatigue
Peak: 110km/week
Taper & Race Prep
2 weeks
Reduce volume while maintaining intensity, focus on recovery and mental preparation, test all gear and nutrition on final long run, arrive early for acclimatization
Peak: 60km/week
Key Workouts
01Hill repeats (6-8 x 3-5 min climbs at 8-10K effort) for leg strength
02Long mountain runs (3-5 hours on varied terrain) for endurance
04Tempo runs on rolling terrain (20-30 min sustained effort) for aerobic threshold
05Vertical gain focused sessions (1500-2000m elevation gain runs) for mountain-specific strength
06Descent practice runs (technical trails with focus on control and speed downhill)
07Race-paced simulations on mountain terrain matching expected race conditions
Get a fully personalized Chihuahua by UTMB® 38K training plan tailored to your fitness, schedule, and goals.
Chihuahua by UTMB® 38K Race Day Tips
1Start conservatively on the opening kilometers—the first hour sets the tone for the entire race, and charging early leads to bonking later on the mountain
2Break the 38km into mental segments: focus on reaching each aid station rather than the full distance ahead
3Practice your power hiking rhythm on climbs before race day; running every climb isn't sustainable—strategic power hiking preserves energy
4Nutrition discipline is non-negotiable; set a consumption schedule for every 30-45 minutes and stick to it even when not thirsty
5Test all gear in training, especially shoes on technical descents—race day is not the time to discover blisters or unstable footing
6Manage your descent effort carefully; many runners lose time to injuries or excessive quad damage by bombing downhills when fatigued
7Stay mentally engaged during middle sections where the race often feels hardest—this is where mental training pays dividends
8Monitor your core temperature and hydration status; mountain conditions can change rapidly and cold/overheating both impair performance
9Use aid stations strategically for mental resets and refueling, not just water—grab specific calories and take 30-60 seconds to reset
10Know your cutoff times and pacing strategy to ensure you finish safely within the time limits
Essential Gear for Chihuahua by UTMB® 38K
Trail running shoes with aggressive tread for technical mountain terrain and secure downhill control
Moisture-wicking base layers that perform in variable mountain weather conditions
Weather-appropriate mid-layer (light insulating layer for altitude and potential cold)
Wind and weather jacket that's packable for variable conditions at elevation
Hydration pack (1.5-2L capacity) that sits stable during climbing and technical sections
Electrolyte or sports drink powder for consistent caloric and electrolyte intake
Sun protection including sunglasses and high-SPF sunscreen for exposed ridge running
Headlamp or lightweight headtorch (essential for any ultra that might push into twilight)
Map and/or GPS device for mountain route finding if not marked clearly
Frequently Asked Questions
How should I train for the elevation gain on the Chihuahua by UTMB® 38K?
Build elevation-specific work into your training by incorporating hill repeats, long vertical gain runs, and back-to-back mountain days. Focus on power hiking technique as much as running—this ultra will require strategic walking on steep sections. Start with 1000-1500m elevation gain runs and progress to 2000m+ sessions. Practice on terrain similar to the actual course if possible. The goal is teaching your body to handle sustained vertical stress while maintaining forward progress.
What's the best nutrition strategy for 38km on mountain terrain?
Plan to consume 30-50g carbohydrates every 30-45 minutes depending on your body and effort level. Mountain running digests differently than road running due to varied pace and altitude, so test nutrition extensively in training. Mix simple carbs (gels, sports drink) with some whole foods (bars, nuts) for sustained energy. Stay on top of electrolyte intake as mountain sweat rates are often higher due to sun exposure and variable pacing. For specific details about aid station locations and spacing, check https://chihuahua.utmb.world.
Should I do altitude training before the Chihuahua by UTMB® 38K?
Altitude training helps if you live near sea level and the race occurs at significant elevation. Live-high-train-low is ideal, but even 2-3 weeks at race elevation helps your body acclimatize. If you can't do this, arrive at least 5-7 days early to acclimate. Understand that performance will be reduced at altitude initially—adjust your pace expectations and focus on completing altitude-specific training sessions to help your body adapt before race day.
How do I prevent bonking and maintain energy on a 38km mountain ultra?
Bonking on mountain terrain is often as much mental as physical. Develop a detailed fueling strategy with specific calories at specific times, not just when hungry. Train your gut to handle food while climbing by practicing nutrition during your long elevation gain sessions. Include some familiar comfort foods that you know digest well. Break the race into 5-8km segments mentally and focus on reaching each aid station rather than dwelling on the full distance. Many bonks occur from dehydration or electrolyte depletion, so prioritize consistent hydration.
What's the optimal pacing strategy for the Chihuahua by UTMB® 38K?
Mountain ultras demand variable pacing based on terrain rather than a fixed pace target. Climb conservatively at a heart rate or effort level you can sustain for hours—expect to power hike significant sections. Run controlled on descents rather than attacking them—blowing out your quads early means suffering later. The middle miles are often hardest psychologically when the race feels longest; maintain steady effort here rather than surging. Use your training to establish what sustainable effort looks like on climbing, running, and descending, then execute that plan with discipline.
How should I approach the technical descent sections during the race?
Technical descents are where many runners lose time to falls or excessive caution, or gain time with controlled aggression. Train descents specifically by practicing on technical terrain weekly. Focus on footfall placement and stability rather than speed. When fatigued late in the race, prioritize safety over time—a fall wastes more time than cautious descending. Choose your line carefully on technical sections, trust your training, and remember that descents are mental as much as physical. Fresh quads and confidence are your assets here.
What should I do if I'm struggling mentally in the second half of the race?
Mental fitness is trained like physical fitness. Use visualization training regularly before the race. During the race, break the remaining distance into 5km chunks and focus only on the next segment. Implement mantras or mental strategies you've practiced in training. Remind yourself that this difficulty is temporary and that you're trained for this. Many runners find that pushing through the mental valley in the middle of an ultra leads to a second wind later. If you're truly struggling, the aid stations are opportunities to reset—eat, drink, take 60 seconds of mental calm, then continue.
How important is course familiarization for the Chihuahua by UTMB® 38K?
Course familiarity provides significant mental and strategic advantages in mountain ultras. Study the course profile, elevation changes, and key landmarks if possible. If you can access video or detailed descriptions of the route, review them multiple times. Running sections of the actual course during training is ideal but not always possible. At minimum, understand where the major climbs and descents occur so you can pace accordingly and have mental checkpoints throughout the race. Visit https://chihuahua.utmb.world for the most current course information.
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