Hydration Packs &
Running Vests Guide
Carry your essentials comfortably for miles. Find the perfect vest for your race.
A vest that bounces, chafes, or doesn't fit will ruin your race long before your legs give out. Proper load distribution keeps you comfortable from mile 1 to mile 100. The right hydration strategy keeps you moving when others stop at aid stations. There's no universal answer — but there is a perfect vest for your distance, body, and race requirements.
Not Sure Which Vest to Get?
Answer 4 questions and we'll match you with the right pack for your race and body.
Vest Finder
Answer 4 questions — we'll match you with the right pack.
Question 1 of 4
What's your race distance?
Race Vests
Best for 50K–50M, minimal gear requirements, race-day speed
Lean, fast, and body-hugging. Race vests prioritize minimal bounce and quick access over raw storage. Perfect when aid stations are frequent and mandatory gear is light.
Salomon ADV Skin 5 Set
ADV Skin 5 Set
$160
Storage
Front: 4 front pockets + 2 soft flask pockets
Back: 3L main + 2L extra
Hydration: 2× 500ml soft flasks included
Best for
Pros
- +SensiFit body-hugging design eliminates bounce entirely
- +Two 500ml flasks included — ready to run out of the box
- +16 pockets in a 5L vest — exceptional organization
Cons
- −Very snug fit — not comfortable for larger chest/shoulder runners
- −5L is limiting for races with extensive mandatory gear
“I've done 12 ultras in the ADV Skin 5. It disappears on my body — I literally forget it's there at mile 40.”
Ultimate Direction Race Vest 6.0
Race Vest 6.0
$130
Storage
Front: Kangaroo pouch + 2 flask pockets
Back: 4L main compartment
Hydration: Compatible with 2L bladder or soft flasks
Best for
Pros
- +Comfort Cinch straps self-adjust mid-run
- +Large kangaroo front pocket fits phone, gels, jacket
- +Best value race vest on the market
Cons
- −No flasks included
- −Back panel less breathable than Salomon
- −Pole stowage system less refined
“The kangaroo pocket is game-changing. Everything I need is one motion away — no fumbling at aid stations.”
Patagonia Slope Runner 8L
Slope Runner 8L
$149
Storage
Front: 2 front stretch pockets + 2 zip pockets
Back: 6L main compartment
Hydration: Bladder sleeve + 2 soft flask compatible
Best for
Pros
- +Made with recycled materials — Patagonia's sustainability commitment
- +8L hits the sweet spot for most ultra distances
- +Exceptional build quality and durability
Cons
- −No pole carry system
- −No whistle included
- −Fewer pockets than Salomon or UD
“I've washed this thing 50 times and it still looks new. Patagonia builds things to last — and that matters for a vest I wear hundreds of miles.”
Nathan Pinnacle 4L
Pinnacle 4L
$120
Storage
Front: 2 angled Exoshot flask pockets + 1 zip pocket
Back: 2L main + 2L side
Hydration: 2× 20oz Exoshot flasks included
Best for
Pros
- +Angled Exoshot flask holders make drinking completely natural
- +Featherlight at 198g
- +Excellent breathability for hot weather racing
Cons
- −4L is strictly for short, supported races
- −No bladder compatibility limits hydration options
- −Limited pole carry
“For supported 50Ks in hot weather, nothing comes close. The angled flasks are the best drinking system I've used.”
All-Around Training & Racing Vests
Best for 50M–100K, versatile for both training and race day
The do-everything vests. Enough capacity for 100K mandatory gear, comfortable enough for daily training, and light enough that you won't notice the weight difference on race day.
Salomon ADV Skin 12 Set
ADV Skin 12 Set
$200
Storage
Front: 6 front pockets + 2 flask sleeves
Back: 6L main + 4L extra + 2 side pockets
Hydration: 2× 500ml flasks included + 2L bladder compatible
Best for
Pros
- +The most trusted vest in ultra running — worn by more elites than any other
- +12L with SensiFit still feels like a race vest
- +20+ pockets with logical organization system
Cons
- −Premium price at $200
- −Salomon's sizing runs very snug — try before buying
“The ADV Skin 12 has been on my back for four Western States, two UTMBs, and countless training runs. It just works.”
Osprey Duro 6 / Dyna 6
Duro 6 / Dyna 6
$140
Storage
Front: 2 front stretch pockets
Back: 4L main + bladder sleeve
Hydration: 2.5L Hydraulics reservoir included
Best for
Pros
- +AirScape back panel is the most breathable in this category
- +Lifetime warranty — Osprey will repair or replace forever
- +Gender-specific fit is genuinely better for both men and women
Cons
- −Bladder-focused design means front flask access is secondary
- −No pole carry system
- −Heavier than Salomon or UD equivalents
“The Dyna fits my chest properly — first vest that doesn't gap or slip. Osprey's women's-specific design is real, not just marketing.”
Nathan VaporKrar 12L
VaporKrar 12L
$160
Storage
Front: 2 wide front pockets + 2 zip pockets
Back: 8L main compartment
Hydration: Compatible with flasks + 2L bladder
Best for
Pros
- +Rob Krar designed — optimized for 100-mile racing demands
- +Wide front pockets fit larger phones and more nutrition
- +12L handles most race mandatory gear requirements
Cons
- −Flasks not included
- −Fit is looser than Salomon — can bounce more if not dialed
- −Pole carry less secure than Black Diamond
“Rob Krar races Hardrock in this thing. That's all the endorsement I need. Front pockets fit everything I need for a 100-mile push.”
Black Diamond Distance 8
Distance 8
$130
Storage
Front: 2 front stretch pockets + 2 zip pockets
Back: 6L main + side pockets
Hydration: Bladder sleeve + soft flask compatible
Best for
Pros
- +Best trekking pole carry system in the category — Z-pole compatible
- +Alpine-grade durability from BD's mountaineering heritage
- +Excellent load distribution for heavier packs
Cons
- −Less organized pocket system than Salomon
- −No whistle included
- −Less body-hugging than ADV Skin series
“I carry poles for every mountain ultra. The BD Distance 8 is the only vest where I can grab and stow poles without stopping.”
Expedition / 100-Mile Vests
Best for 100M, multi-day, self-supported, heavy mandatory gear
When your race demands a bivy, rain jacket, emergency kit, night gear, and two days of nutrition, you need real capacity. These vests carry it all without sacrificing the running vest form factor.
Salomon ADV Skin 18 Set
ADV Skin 18 Set
$230
Storage
Front: 6 front pockets + 2 flask sleeves
Back: 12L main + 6L extra pockets
Hydration: 2× 500ml flasks included + 3L bladder compatible
Best for
Pros
- +18L that still runs like a race vest — remarkable engineering
- +Handles full UTMB mandatory gear list with room to spare
- +SensiFit scales to larger loads without bounce
Cons
- −Premium $230 price tag
- −18L feels excessive for anything shorter than 100K
- −Heavy when fully loaded — expect to notice it at mile 80
“UTMB's mandatory gear list is brutal. The ADV Skin 18 is one of the only vests that fits it all and still lets me run properly.”
Ultimate Direction Fastpack 25
Fastpack 25
$200
Storage
Front: 2 front pockets + 2 zip pockets
Back: 20L main + side pockets
Hydration: 2L bladder compatible + flask pockets
Best for
Pros
- +25L genuinely accommodates sleeping gear for stage races
- +Exceptional load distribution for heavy packs
- +UD's durability is industry-leading
Cons
- −560g is heavy compared to race vests
- −Overkill for single-day 100-milers with crew
- −Noticeably more bounce than smaller vests when full
“PTL requires carrying a sleeping bag, bivy, and two days of food. The Fastpack 25 is the only running vest that actually works for that.”
Raidlight Revolutiv 18L
Revolutiv 18L
$180
Storage
Front: 4 front pockets + 2 flask pockets
Back: 12L main + 4 external pockets
Hydration: 2 soft flasks + 2L bladder compatible
Best for
Pros
- +French brand built for UTMB — knows mandatory gear demands inside out
- +18L at 350g is excellent weight-to-capacity ratio
- +Waterproof back pocket for electronics
Cons
- −Less widely available outside Europe
- −Fit can be inconsistent across sizes
- −Less brand recognition means less resale value
“Raidlight built this vest for the UTMB circuit. It shows — every pocket placement makes sense when you're navigating mandatory gear requirements.”
Minimalist Race Vests
Best for supported 50Ks, elite racers, ultra-light approaches
When mandatory gear is minimal and aid stations are frequent, carry only what you need. These vests are the difference between running and hauling — barely there, never noticed.
Salomon Pulse 2 Set
Pulse 2 Set
$80
Storage
Front: 2 flask pockets + 1 small zip
Back: 1L back pocket
Hydration: 2× 500ml flasks included
Best for
Pros
- +100g — you will genuinely forget you're wearing a vest
- +Two 500ml flasks included at an $80 price point
- +Salomon's SensiFit body-mapping even in this minimalist form
Cons
- −2L is only suitable for supported races with close aid stations
- −No mandatory gear capacity
- −Not durable enough for heavy training use
“I wore this at a road 50K and felt like I was running in just a singlet. Total weight including flasks was barely 300g.”
OMM TrailFire
TrailFire
$100
Storage
Front: 2 flask pockets + 1 flat pocket
Back: 3L flat storage
Hydration: Soft flask compatible
Best for
Pros
- +OMM's fell running heritage — built for conditions, not comfort
- +Flat-pack design sits incredibly close to the body
- +British ultra racing pedigree
Cons
- −No flasks included
- −4L is restrictive for anything with mandatory gear
- −Limited availability outside UK market
“The fell running community has trusted OMM for decades. The TrailFire is as minimal as a vest can get while still being functional.”
Hydration Strategy by Distance
Your vest capacity should match your hydration needs between aid stations — not just the total race distance.
50K
1–1.5L total
Setup: 2× 500ml front flasks
Aid stations: Every 5–10 miles
- →Front-only flasks usually sufficient
- →No bladder needed for most courses
- →Electrolyte tabs in front zip pocket
- →Race day: know aid station distances
50 Miles
1.5–2L
Setup: 2× 500ml flasks + optional 1L bladder
Aid stations: Every 8–15 miles
- →Consider adding a bladder for remote sections
- →Night section may require extra capacity
- →Pre-load electrolytes at aid stations
- →Know the longest gap between aid stations
100K
2–2.5L
Setup: 2× 500ml flasks + 1.5L bladder
Aid stations: Every 10–20 miles
- →Redundant hydration systems critical
- →Remote sections may have 15+ mile gaps
- →Night sections need extra planning
- →Practice refilling while moving
100 Miles
2–3L
Setup: 2× 500ml flasks + 2L bladder or crew support
Aid stations: Every 5–20 miles (varies)
- →Crew support can simplify hydration
- →Drop bag flask rotation at key points
- →Night running: flasks easier than bladder
- →Sweat rate changes significantly after mile 60
Front Flasks vs. Back Bladder
Soft Flasks (Front)
- +See exactly how much you have left
- +Easier to refill at aid stations
- +Can mix different drinks in each
- +No tube to clean or maintain
- +Better for night running (feel for flask)
- +Industry trend — most elites use flasks only
Hydration Bladder (Back)
- →Larger continuous capacity (2–3L)
- →Hands-free sipping via tube
- →Better for runners who forget to drink
- →Good for remote sections without aid stations
- →Harder to know remaining volume
- →Cleaning is more involved
Vest Features Explained
Know what you're buying. These are the features that actually matter after 50 miles.
Pocket Systems
Front flask pockets
Should hold flasks at an angle accessible while running. Depth and elasticity matter — shallow pockets bounce.
Kangaroo / overflow
Large stretchable front pocket for bulkier items (jacket, food). UD's design is best-in-class.
Zippered security
For phone, money, ID. Waterproof rating matters — sweat ruins electronics.
Back main compartment
Where mandatory gear, layers, and larger items live. Should have one large opening, not multiple small ones.
Adjustment Systems
Sternum straps
Multiple height positions allow dialing in chest fit. Critical for reducing bounce and accommodating different chest shapes.
Side compression
Pull cords on sides compress load as you consume food and water. Prevents sloshing and dead space.
Shoulder strap
Fixed on most vests. Some offer torso length adjustment — essential for very short or tall runners.
Bottom hem cinch
Stabilizes vest during technical running. Often overlooked but significantly reduces vertical bounce.
Pole Carry Systems
Diagonal back carry
Best for long-term storage. Poles go across the back. Requires practice to stow while moving.
Stow-on-the-go
Salomon's system: loop poles into elastic on shoulders while running. The best solution for mountain ultras.
Side pocket stash
Quick but tips heavy poles forward. Good for short sections. Not ideal for technical descents.
Z-pole compatibility
Black Diamond's folding poles designed to slot into BD vests. The most secure carry system.
Breathability
Mesh back panels
Allow air circulation between vest and body. Critical in summer. Osprey's AirScape is the benchmark.
Seamless construction
Reduces chafing contact points. Salomon's skin-mapped design eliminates seams on high-friction areas.
Laser-cut ventilation
Precision holes in panels for airflow. Adds breathability without compromising structure.
Quick-dry fabrics
Lightweight polyester dries fast. Important for creek crossings and rain sections.
Weather Protection
DWR coating
Durable water repellent treatment on outer fabric. Beads water in light rain. Not waterproof — just resistant.
Waterproof pockets
True waterproof (not just resistant) pockets for phone and electronics. Look for taped seams.
Insulated pockets
Some vests offer insulated front flask pockets to keep drinks cooler in heat or prevent freezing in cold.
Pack covers
Aftermarket rain covers are an alternative to built-in waterproofing. Easier to deploy mid-run.
Safety Features
Integrated whistle
Required by some races. Should be accessible without removing vest. Many brands include on sternum strap.
Reflective elements
360-degree reflectivity matters for night sections. Look for reflective on both front and back panels.
Blinker/light attachment
Loop or clip for attaching a blinker light to the back. Critical for night running safety.
Emergency ID pocket
Small pocket for ICE (In Case of Emergency) card with medical info and emergency contacts.
Sizing & Fit Guide
A vest that fits wrong will chafe, bounce, or restrict your breathing. Get sizing right before race day.
How to Measure
- →Chest circumference: measure around the fullest part of your chest
- →Torso length: C7 vertebra (base of neck) to iliac crest (top of hip)
- →Measure in centimeters for most vest sizing charts
- →Measure after a run — body size changes slightly when warm
- →Women: measure band size AND cup — some vests have cup-specific fits
Brand Sizing Notes
- →Salomon: runs very snug — size up if between sizes
- →Ultimate Direction: true to size, good range for broad builds
- →Osprey: generous sizing, excellent for larger builds
- →Patagonia: true to size with good shoulder room
- →Nathan: slightly generous — consider sizing down if between sizes
Fit Testing
- →Always test with water in flasks — weight changes fit significantly
- →Fill to your expected race load and run 20+ minutes
- →Adjust all straps while running, not standing still
- →Check for: chafing under arms, bouncing, breathing restriction
- →A vest should feel snug but not compressive — you should breathe freely
Common Fit Issues
- →Bouncing: tighten sternum straps + side compression + reduce weight
- →Chafing under arms: wrong size or wrong vest design for your build
- →Chest gap (women): vest is not women's-specific or wrong size
- →Shoulder pain: load redistribution needed or wrong torso length
- →Breathing restriction: loosen chest straps or try a larger size
Layering Considerations
- →Winter races: order your vest with your thickest base layer in mind
- →Most runners order 1 size up for cold weather use with layers
- →Soft shells under a vest: ensure vest sits over, not under
- →Rain jackets: go on top of vest — never trap the vest underneath
- →Test with your actual race kit — not just a t-shirt
Break-In & Maintenance
- →Run at least 3–5 training runs in your vest before race day
- →Mark optimal strap positions with a marker after dialing in
- →Hand wash with mild detergent — never machine dry
- →Store with straps loose to prevent elastic memory
- →Bladder: rinse after every use, air dry fully before storing
Race-Specific Recommendations
Different races have wildly different gear requirements. Here's what to bring where.
| Race | Capacity | Conditions | Top Picks | Key Needs |
|---|---|---|---|---|
| Western States 100 | 8–12L | Hot canyons, crew access frequent | ADV Skin 12, VaporKrar 12L | Heat management, easy refill |
| UTMB | 12–18L | Alpine, extensive mandatory gear, weather variability | ADV Skin 18, Revolutiv 18L | Full mandatory gear, pole carry, waterproof pockets |
| Hardrock 100 | 12–15L | High altitude, remote, mountain terrain | ADV Skin 12/18, Fastpack 25 | Self-sufficiency, pole carry, alpine durability |
| Leadville 100 | 8–12L | High altitude, crew access good, weather extremes | ADV Skin 12, Slope Runner 8L | Altitude layering room, weather adaptability |
| Moab 240 | 15L+ | Multi-day, desert, maximum organization | Fastpack 25, ADV Skin 18 | Max capacity, food storage, desert heat management |
Packing Strategy
How you pack is as important as what you pack. Poor organization costs minutes at aid stations and causes unnecessary suffering on the trail.
What Goes Where
Weight Distribution
- →Heavy items (water, food) as close to your back and center as possible
- →Balance left and right — asymmetric loading causes hip and shoulder issues over 50+ miles
- →Lower heavy items to reduce lever arm effect on shoulders
- →Use compression straps to eliminate dead space as the pack empties
- →Rebalance at every major aid station — the load changes dramatically as you eat and drink
- →Practice with your expected race-day weight, not an empty vest
Frequently Asked Questions
How much capacity do I really need?▾
Front flasks vs. back bladder — which is better?▾
How tight should my vest be?▾
Will my vest work in winter with layers underneath?▾
What's the difference between men's and women's vests?▾
Do I need a vest for a 50K?▾
How do I prevent chafing?▾
Are expensive vests ($180-250) worth it?▾
How do I carry trekking poles when not using them?▾
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