International Trail Race: UTMF (Mt. Fuji Circuit) — Asia's Premier 165K Event

Introduction

UTMF (Ultra-Trail Mt. Fuji) is Japan’s most iconic trail race, circling Mt. Fuji over approximately 165K with over 7,500m of cumulative elevation gain. Founded in 2012, it is part of the UTMB World Series and a key pathway for accumulating Running Stones in Asia. For Taiwanese trail runners, UTMF is an ideal springboard to the UTMB main event.

Race Basic Information

Item	Details
Distance	165K
Cumulative Elevation Gain	Approx. 7,500m
Cutoff Time	44 hours
Start / Finish	Around Mt. Fuji
ITRA Points	4 Running Stones
Main Month	Late April
Finish Rate	Approx. 55-65%

UTMF Course Features

1. Circling Mt. Fuji

The UTMF course circles Mt. Fuji, offering views of:

• Mt. Fuji 5th Station
• The Fuji Five Lakes (Lake Yamanaka, Lake Kawaguchi, Lake Sai, Lake Shoji, Lake Motosu)
• Aokigahara Sea of Trees
• Multiple Mt. Fuji viewpoints

2. High-Quality Course Markings

Japanese races are renowned for their meticulousness:

• Markers every 100-200m
• Complete reflective markers for nighttime
• Clear signage at aid stations
• Well-established emergency rescue system

3. Aid Station Culture

Japanese trail race aid station highlights:

• Japanese rice balls, miso soup, and udon noodles at aid stations
• Local specialties (Koshu grapes, Mt. Fuji spring water)
• Friendly and courteous staff
• Wide variety of aid station food

4. Spring Climate

Late April weather around Mt. Fuji:

• Daytime 10-18°C
• Nighttime 0-8°C (possible snow at higher elevations)
• Occasional spring rain
• Possible lingering snow at some altitudes

Course Analysis

The UTMF course is divided into four main sections:

Section	Distance	Cumulative Elevation Gain	Key Features
Stage 1	0-40K	1,800m	Lake Kawaguchi area, first major climb
Stage 2	40-80K	2,200m	Entering Aokigahara Sea of Trees, first night section begins
Stage 3	80-120K	2,000m	Lake Sai and Lake Motosu area, second night section
Stage 4	120-165K	1,500m	Lake Yamanaka area, final climb

Pacing Strategy

Tailored to UTMF characteristics:

Stage 1 (0-40K, target 8 hours)

• Start at 3:00 PM, first 5 hours in daylight
• Control pace, 5% slower than UTMB pace
• Walk the first climb
• Reach the Stage 1 aid station before sunset

Stage 2 (40-80K, target 11 hours)

• Enter the first night section
• Misty forest atmosphere in the Aokigahara Sea of Trees section
• Keep heart rate in Zone 2
• Full hot meals at aid stations

Stage 3 (80-120K, target 12 hours)

• A new round of challenges begins early on the second morning
• Lake Sai and Lake Motosu area is scenic but fatigue accumulates severely
• Caffeine intake at aid stations
• The mental battle begins

Stage 4 (120-165K, target 10 hours)

• Enter the second night section
• 36+ hours accumulated without sleep
• Micro-sleep strategy
• Final 10K push

Gear Recommendations

Mandatory Gear

UTMF mandatory gear list:

• Trail backpack 10L+
• Water container of at least 1L
• Headlamp + spare headlamp
• Waterproof jacket (strict waterproof rating requirements)
• Insulation layer
• Emergency blanket
• Whistle
• Mobile phone
• Cup
• Complete race documentation

Recommended Gear

• Soft flasks ×2 + 1L bladder
• Insulation layer (synthetic or wool, essential for night sections)
• Hat + gloves
• Sunglasses
• Spare batteries ×3 sets
• Petroleum jelly (anti-chafing)

Nutrition Strategy

Stage 1

• 200ml water + 1 salt tablet every 30 minutes
• 1 energy gel every 45 minutes
• Start trying Japanese rice balls at aid stations

Stage 2 (First Night Section)

• Change into insulation layer and put on headlamp before sunset
• Must eat hot food at aid stations (miso soup, udon noodles)
• 100mg caffeine intake
• Slightly reduce water intake (to avoid multiple nighttime bathroom breaks)

Stage 3

• Breakfast: rice balls and bananas from aid stations
• Temperatures rise around midday, increase water intake
• Maintain 60g of carbohydrates per hour

Stage 4 (Second Night Section)

• Eat hot food at every aid station
• Maintain caffeine intake
• Take a 15-minute short nap if necessary
• No more solid food in the final 20K (to avoid stomach discomfort)

Training Recommendations

Training focus for UTMF:

1. Ultra-Long Distance

One 40-50K long run per week for 6 months before the race.

2. Back-to-Back Training

Do 1-2 back-to-back sessions 8 weeks before the race:

• Saturday: 50-60K
• Sunday: 25-30K

Simulate the feeling of running under continuous fatigue.

3. Night Running

Complete 3-5 full night runs before the race to familiarize yourself with headlamp use and nighttime pacing.

4. Cold Adaptation

If you live in a tropical region, allow 2 weeks before the race to adapt to 5-15°C temperatures.

Travel Planning

Pre-Race Preparation

• Arrive in Japan 3 days early to adjust to the time difference
• Gear check 2 days before the race (strict mandatory gear list)
• Race briefing 1 day before the race
• Pre-race dinner: Japanese carbohydrate meal (soba noodles, udon noodles, rice)

Post-Race Planning

• Stay around Mt. Fuji for 1-2 days after finishing
• Visit Lake Kawaguchi, Fuji-Q Highland, and Tokyo
• Relax in an onsen after the race

Practical Tips

• Registration Lottery: UTMF uses a lottery system, requiring accumulated Running Stones
• Language Preparation: Japanese staff have limited English; prepare an English-Japanese phrase list (aid station food names)
• Cash Needs: Some shops around Mt. Fuji only accept cash
• Data SIM: Japanese telecom companies offer short-term 4G SIM cards
• Weather Contingency: Occasional spring snow in late April; waterproof gear is essential

Conclusion

UTMF is the ideal springboard for Asian trail runners aiming for the UTMB main event. The race’s high quality, the unique route circling Mt. Fuji, and the meticulousness of Japanese trail culture make UTMF more than just a race—it’s a deep cultural and natural experience. When planning your next international race, put UTMF on your spring calendar. This race gives you not just 4 Running Stones, but a profound understanding of the Japanese trail-running spirit.

Related Reading

• Trail Race Strategy: A Finish Guide for 100-Mile Races like UTMF and TNF100
• The UTMB-Level Trail Race Preparation Path: An 18-Month Roadmap
• Taiwan Mountain Ultra: A Preparation Guide for UTMB Asia Series Races
• 8,500 Runners on the Same Course: Mt. Fuji Subaru Line, Asia’s Largest Hill Climb Pilgrimage