Trail Hydration Packs & Vests
3 L, 7 L, 12 L and 15 L hydration vests, designed in Brittany and tested in races before being approved.
- Breton brand
- Tested by our athletes
- Refund within 15 days
- Pay in 4 installments from €70
69 Products
BAG RK3 LEOPARD X BRETON STRIPE
44,99 €
BAG RK3 HEARTRUNNEUSE
44,99 €
RK7 PANTHERA PACK
74,99 €
SAC RK3 RDK BZH FLAG BLACK
44,99 €
RK7 LEOPARD CHOCO PACK
74,99 €
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A hydration vest is worn close against the chest and adjusted so it does not move a millimeter on descents. A trail backpack is worn on the shoulders and carries more. The choice does not depend on the brand but on one question: how long you will be outside and what the race regulations require you to carry.
At Kinetik, the range is divided into two families. The RK3 are lightweight hydration vests, designed for long outings and distances up to trail marathons. The RK15 are 15 L packs, sized for ultras and races with mandatory equipment. Both are designed in Brittany, using our own materials, and tested by our athletes before being approved.
How to choose between a vest and a trail pack
Capacity, dictated by the length of the outing
Our range comes in four capacities, 3 L, 7 L, 12 L and 15 L. For outings under two hours, a minimalist vest is enough: two flasks at the front, a windbreaker, and something to eat. Between two and six hours, you need room for an extra layer, supplies, and a phone. Beyond that, race regulations often require a mandatory equipment list that determines the capacity for you. This is the dividing line between our 3 L, 7 L, 12 L, and 15 L formats.
The fit, the real criterion
A vest that is too large bounces around, rubs, and causes irritation at the armpits and collarbones over long distances. A vest that is too tight compresses the rib cage and makes breathing uphill difficult. The fit must be adjusted when loaded, never empty: a vest that fits perfectly when empty becomes loose once the flasks are full and the food has been taken out.
The test to do in-store or at home before cutting off the tag: fill it, tighten it, then jump in place twenty times. If anything moves, it is not the right size or the right adjustment.
Accessing hydration on the move
Two schools of thought. Front flasks, accessible without stopping or removing the pack, but which take up space on the chest. The back hydration bladder, more discreet and with a larger capacity, but which means managing a hose and makes checking the remaining level more difficult. Many trail runners combine both on long distances. Our AkuaFlask 350 ml and AkuaFlask Neo 500 ml fit into the front pockets of the RK3 and RK15.
Weight and bulk
This is our starting point for product development: the weight and bulk of equipment are the two problems we seek to solve. A vest should not be judged only by its empty weight, but by how it distributes the load once full. Good front-to-back load distribution does more for comfort than saving twenty grams on the fabric.
Which model for which outing
| Your activity | Our recommendation | Why |
|---|---|---|
| Short outings, under 2 hours | RK3 vest | Minimalist format, two flasks at the front, nothing protruding |
| Long outing or short trail race | RK3 vest | Enough volume for a windbreaker and provisions |
| Ultra or race with mandatory equipment | RK15 pack | 15 L, enough room for the list required by the organizers |
| Intermediate format, moderate range | 7 L vest or 12 L | The compromise between the bulk of the 3 L and the capacity of the 15 L |
You may also like
- 3 L vestsThe minimalist format for short, fast outings
- 15 L packsUltras and races with mandatory equipment
- Hydration beltsThe lightweight alternative to the vest
A Breton brand that designs its own materials
Kinetik is a Breton family business. We design and develop our products ourselves, including the materials, rather than picking from supplier catalogs. This way of working is slower, but it allows us to precisely correct what causes problems in the field: a seam that rubs after six hours, a strap that slips on descents, a fabric that retains moisture.
Our products are tested by our athletes before approval. Knowledge of the terrain is not a marketing argument for us; it is our development method. And because trail running is not practiced in uniform, we continually expand the available designs, while the market often offers three technical colorways and nothing else.
Our range covers the runner's essential needs, from cap to sock. We also equip clubs, teams and race organizers with products personalized in their colors.
Frequently asked questions
What is the difference between a hydration pack and a hydration vest?
The vest conforms to the torso and adjusts laterally to eliminate bouncing. It carries water at the front, accessible while running. The backpack distributes the load across the shoulders and carries more, at the cost of less direct access. For trail running, the vest is standard up to medium volumes; the backpack takes over for ultras and races with mandatory equipment.
What pack volume for a 50 km trail race?
It depends less on the distance than on the regulations. First check the event's mandatory equipment list: waterproof jacket, emergency blanket, minimum water supply, phone, and sometimes a cup and whistle. This list determines the minimum volume. For complete self-sufficiency without a mandatory list, allow more capacity rather than just enough.
How can I prevent the bag from bouncing on descents?
Adjust it when fully loaded, never when empty. First tighten the lower side straps, then the upper ones, while ensuring you can still breathe deeply. Distribute the weight: keep heavy items as close to your back and as high up as possible. Finally, do the jump test on the spot twenty times with the bag full. If it still moves, the size is not right.
Flasks at the front or a hydration bladder on the back?
You can drink from flasks without slowing down, and you can see how much remains, which helps you manage hydration on a long outing. A hydration bladder offers more capacity and frees up your chest, but requires managing a tube and makes tracking the remaining volume approximate. On long outings, many people combine both.
How can I prevent chafing and irritation?
Three main causes: an adjustment that is too loose, a poorly placed seam, or fabric that stays damp. Adjust the vest so it sits close to your body, without slack. Make sure no seam runs over your collarbones or under your armpits. Also avoid cotton base layers, which retain perspiration and turn even the slightest rubbing into chafing after a few hours.
How do I wash a hydration vest?
Rinse with clean water after every outing, paying particular attention to the areas in contact with your skin where salt accumulates. Hand-wash or machine-wash at 30 °C in a mesh laundry bag, without fabric softener: fabric softeners clog technical fibers and prevent moisture from being wicked away. Air-dry, never in a tumble dryer or on a radiator.
How do I choose the right size?
Chest circumference is the determining measurement, not your usual clothing size. Measure at the end of a normal inhalation, without holding your breath. If you are between sizes, choose the smaller one if you mostly run short and light, and the larger one if you often carry a heavier load. The size guide is shown on each product page.
Can a bag be customized in a club's colors?
Yes, it is an important part of our business. We equip clubs, teams, and race organizers with customized gear. The terms, minimum quantities, and lead times are detailed on our pages dedicated to clubs and event organizers.
Content updated in September 2026.