UTMB Mandatory Kit: Vests, Packs, and What You Actually Need

What the UTMB Mandatory Kit Actually Requires

If you’re lining up for UTMB, the race checklist can feel overwhelming. But the UTMB mandatory kit list is non-negotiable, and showing up without the right gear means you won’t start. The core of that kit? Your vest or pack. It must meet specific capacity, pocket, and material requirements. Let’s break down what you actually need—and which products pass inspection.

UTMB Vest Requirements: Capacity, Pockets, and Fit

The rules are simple but strict. Your pack must hold at least 1.5 liters of water (two bottles or a bladder), plus all mandatory items without bulging. The UTMB vest requirements also demand a minimum of two front pockets for quick access to gels or a phone. Most modern ultra packs exceed this, but older models might not.

Why Pocket Count Matters

You need one pocket for your phone (for safety tracking) and another for nutrition. Many vests have four to six front pockets, but two is the legal minimum. Check the official UTMB gear list: if your pack lacks a designated phone pocket, you’ll need to add a waist belt or separate pouch.

Fit and Stability

A loose pack that bounces will cost you energy. UTMB doesn’t test fit, but your comfort depends on it. Look for adjustable sternum straps and a snug waist belt. The Salomon ADV Skin 12 (€160, 260g) is a gold standard here—its four-point adjustment system keeps everything locked in place.

Ultra Running Pack Guide: Top Models for UTMB

Not all packs are created equal for a 100+ mile race. Here’s a quick ultra running pack guide to three models that clear the mandatory kit bar.

Salomon ADV Skin 12

• Capacity: 12L (main compartment) + 2L front bottles
• Weight: 260g
• Pockets: 6 front pockets, 2 side stash pockets
• Price: ~€160
• Why it works: The soft flask sleeves are angled for easy self-siphoning. It also has a dedicated phone pocket with a waterproof lining.

UltrAspire Alpha 8

• Capacity: 8L (main) + 1.5L front bottles
• Weight: 220g
• Pockets: 4 front pockets, 2 hip belt pockets
• Price: ~€140
• Why it works: It’s lighter than the Salomon by 40g, but the front pocket count is lower. You’ll need to use the hip belt for your phone.

Nathan VaporKrar 12L

• Capacity: 12L (main) + 2L front bottles
• Weight: 310g
• Pockets: 5 front pockets, 2 side mesh pockets
• Price: ~€150
• Why it works: The mesh back panel breathes well in heat. It’s 50g heavier than the Salomon, but some runners prefer the extra structure for heavier loads.

Comparison data point: The UltrAspire Alpha 8 at 220g is 40g lighter than the Salomon ADV Skin 12 (260g), but it sacrifices two front pockets. If you carry a phone and gels simultaneously, you might miss those pockets during a long climb.

Shoes and Gels: The Unsung Mandatory Items

Your vest is the star, but UTMB also requires your shoes to have a minimum tread depth of 2mm (most trail shoes exceed this). And gels? They’re not mandatory, but you’ll need them for energy. Here’s how the gear tables line up.

Trail Shoe Specs (UTMB-Ready)

Comparison data point: The HOKA Speedgoat 6 at 228g is 18g heavier than the Salomon S/Lab Ultra 3 (210g), but it offers a wider toe box and better cushioning for long descents. Choose based on your foot shape, not just weight.

Gel Options for Ultra Distance

Recommendation: Pack at least 8-10 gels for the 100-mile distance. The Maurten Gel 100 is easier on the stomach at high intensity, but the GU Roctane gives you a caffeine boost for night sections.

How to Pack Your Vest for UTMB Inspection

Race check-in is where your UTMB mandatory kit gets scrutinized. The volunteer will ask you to unpack everything. Here’s a pro tip: use a dry bag for your spare headlamp and survival blanket. It keeps them dry and makes your pack look organized.

The 10-Second Unpack Test

1. Water: Show both bottles or bladder (minimum 1.5L total).
2. Lighting: Two headlamps with fresh batteries (one must be a spare).
3. Safety: Survival blanket, whistle, and mobile phone (charged).
4. Nutrition: At least 500 calories of gels or bars (they don’t check brand, but have them accessible).

If your pack has a roll-top closure, practice rolling it tight. A loose roll can waste space and make items harder to find.

Common UTMB Kit Mistakes to Avoid

Even experienced runners get tripped up. Here are three frequent errors:

1. Underestimating Water Capacity

Your pack must hold 1.5L. Many vests come with 500ml bottles (1L total). You’ll need to add a third bottle or switch to a 1.5L bladder. The Salomon ADV Skin 12 includes two 500ml flasks, but you can swap them for 750ml versions (sold separately).

2. Forgetting the Spare Headlamp

UTMB requires two headlamps. One can be a small backup like the Petzl Bindi (35g, €40). It fits in a front pocket and won’t weigh you down.

3. Overpacking Your Vest

A 12L pack is plenty for UTMB. Don’t stuff it with extra jackets or food you won’t eat. Stick to the mandatory list plus your gels, phone, and a lightweight rain jacket. A 12L pack loaded to 15L will bounce and chafe.

Final Checklist Before Race Day

Before you leave for Chamonix, run through this quick audit:

• Vest capacity: 12L minimum? Check.
• Front pockets: At least two? Check.
• Water system: 1.5L total (bottles or bladder)? Check.
• Headlamps: Two, with fresh batteries? Check.
• Shoes: Tread depth ≥2mm? Check.
• Gels: 8-10 gels (or 500+ calories)? Check.

If you’re missing anything, our gear database has you covered. Browse our shoes category for trail-ready options like the HOKA Speedgoat 6 or Salomon S/Lab Ultra 3. For your vest, check the vests category to compare the Salomon ADV Skin 12, UltrAspire Alpha 8, and Nathan VaporKrar 12L. And don’t forget your gels category —stock up on Maurten or GU Roctane for race day.

The UTMB mandatory kit isn’t just a checklist—it’s your lifeline for 100 miles. Pack smart, train hard, and see you at the start line.