Key takeaways: The volume size depends on the distance and required gear—ranging from 3 liters for short rides to 12 liters or more for ultra rides. The hydration system depends on the terrain: front bottles for greater responsiveness, a hydration bladder for remote routes. A good fit eliminates side-to-side rubbing.
A backpack that’s too big wobbles because it’s half-empty. A backpack that’s too small forces you to leave mandatory gear in the locker room and results in you being turned away at the checkpoint. Somewhere in between lies the perfect size, which depends primarily on the actual duration of your trips—not on your dreams. We’ll go over the criteria for pack size, the two hydration systems, and what distinguishes a comfortable fit from one that starts to rub your sides after the 30th kilometer.
Table of Contents
The Right Volume Size for Each Distance
Three factors determine this: your water needs, the mandatory gear specified by the organizer, and the length of time you’ll be carrying everything on your back.
Short rides and training runs under two hours
For a ride of this length, your water needs are limited—between 500 ml and 1 liter, depending on the temperature. A 3-liter backpack is more than enough for your front water bottles, a few energy gels, and a windbreaker in case it gets windy. The goal here is for the backpack to be completely unnoticeable when you’re carrying it. Buying more volume just to be safe is counterproductive: the empty space causes the load to shift around, and you end up with exactly the bouncing you wanted to avoid.
Middle-Distance Races and Nature Marathons
Between 40 and 80 kilometers, the situation changes. You’ll need to pack a rain jacket, food for several hours, and safety gear. A 7-liter capacity offers the best balance between storage space and weight. This is the most versatile model in the product line, suitable for both long Sunday training rides and most runs requiring lightweight mandatory gear.
Ultra-Trail and Long-Distance Comfort
On ultra-distance runs, the list of required gear is extensive: a headlamp and spare batteries, a survival blanket, a rain jacket, a cup, and sometimes an extra layer of warm clothing for the night. You’ll need a 12-liter backpack with quick access to the side pockets so you don’t waste time at every aid station. Weight management becomes a real strategy here: Every item you carry must justify its place; otherwise, it will take a toll on you if you run out of strength to carry it by the end.
| Tour Type | Recommended Volume Size | Water Demand |
|---|---|---|
| Less than 2 hours | 3 L | 500 ml to 1 L |
| Long-Distance Rides, 40 to 80 km | 7 L | 1 to 1.5 L |
| Ultra-distance Rides, 100 km and More | 12 L and more | 1.5 to 2 L |
Water bottles or hydration bladders: Which system is right for your activity level?
Once you've chosen the right capacity, you'll need to decide how you'll carry the liquid. This choice directly affects your drinking rhythm and, as a result, your performance during the race.
The Responsiveness of the Front Bottles
With the drinking tubes attached to the straps right in front of your mouth, drinking becomes a reflex action rather than a conscious decision. You drink more regularly without interrupting your running rhythm to take a sip. As the water level drops, the bottle’s movement slows down, and you can constantly keep an eye on the water level—which helps you plan your water intake between refills.
Three specific advantages:
- Quick refills at the aid stations in just a few seconds.
- An immediate visual overview of the remaining fill level.
- The ability to transport water and high-calorie beverages separately.
The hydration bladder on the back
A hydration bladder is especially useful on remote trails when the next water source is three hours’ run away. It allows you to easily carry 1.5 to 2 liters of water, and the weight concentrated on your back stabilizes the entire setup. The downside is maintenance: the tube and valve must be thoroughly dried after every run; otherwise, mold will form within a few days. If you don’t want to be that careful, stick with front-mounted water bottles—you’ll save yourself some unpleasant surprises.
Find the right volume for your distance
Kinetik The company designs its backpacks in Brittany, where they have been tested on coastal hiking trails since 2008. From the minimalist 3-liter model to the 12-liter model for ultra-long hikes—each features a fit that hugs the upper body and prevents unnecessary movement. Discover the entire Comfort Line to find the right model for your hikes.
Ergonomics and Lightweight Design: Comfort Without Friction
A backpack that's the right size but doesn't fit well will still be uncomfortable. The design and materials do the rest.
Breathable Materials and Sweat Management
The 3D mesh creates a layer of air between the backpack and your back, which wicks away sweat instead of trapping it. During strenuous ascents, this prevents your back from getting wet and helps avoid a sudden drop in body temperature once you reach the summit and are exposed to the wind. Stretchy fabrics then help reduce chafing: The backpack follows the movements of your upper body instead of rubbing against it—and it’s precisely on the sides where most chafing occurs during long-distance hikes.
Morphological Adaptation and Women's Cuts
Women's-specific cuts aren't just a marketing gimmick. A poorly positioned strap creates a painful pressure point on the chest, and no adjustment can compensate for an ill-fitting cut. Weight distribution is just as important: A balanced weight distribution between the front and back supports your posture and prevents you from leaning forward when wearing larger sizes.
Material Organization and Customization
A well-organized backpack saves you time at every stop. The key to saving time is how the pockets are organized.
Placement of Bags and Attachment of Poles
Assign a fixed spot to each category of items and don’t change it. You should be able to grab a gel, your race number, or your whistle without thinking and without taking off your backpack—even if your fingers are numb. For running poles, front straps or a removable holder allow you to secure them while running. You can find the selection criteria in our guide to trail running poles.
| Equipment | Recommended Seat | Grund |
|---|---|---|
| Bottles | Gurte | Faster, direct access without stopping |
| Rain Jacket | Backpack | High volume, only occasional use |
| Energy Requirements | Front Side Pockets | Access During the Run |
| Pipe | Belt Mounting | Safety equipment, immediate access |
The KUSTOM Service for Clubs
KUSTOM enables clubs, associations, and race organizers to customize their gear in their own colors. Beyond mere aesthetics, this serves as a true unifying force for a group that gathers at the starting line early in the morning. Kinetik remains a family-owned and independent company based in Saint-Quay-Portrieux, with in-house R&D and on-site testers. For club projects, this is particularly evident in the responsiveness that major brands simply cannot offer.
When choosing a hydration pack, consider a capacity based on your actual hikes, a hydration system suited to your terrain, and a fit that prevents chafing. The rest is just fine-tuning. Whether you ’re just starting out with 3-liter backpacks, working your way up to 7-liter backpacks, or planning an ultra-tour with a 12-liter backpack, the “ Kinetik ” product line is available with 4 interest-free installment payments starting at €70 and free shipping on orders of €100 or more.
FAQ
What backpack size should I choose based on the distance?
For hikes under two hours, a 3-liter backpack is sufficient. For long hikes and runs with lightweight mandatory gear, a 7-liter backpack is recommended. For ultra-hikes, you should opt for a 12-liter backpack or larger. Always check the mandatory gear list provided by the event organizer before making a purchase: The organizer determines the minimum capacity, not your personal comfort level.
Soft water bottles or a hydration bladder?
The front bottles offer immediate access and quick refills at water stations. As the liquid level drops, they become less bulky, and you can always keep an eye on how much is left. The rear hydration bladder is better suited for remote routes, with a capacity of 1.5 to 2 liters and a centered weight distribution. However, it requires thorough drying after each use: the reservoir and tube should be separated and left in an open position.
How can I prevent friction on the sides?
Look for breathable materials like 3D mesh and stretchy side panels that move with your upper body—these help eliminate friction points. Then adjust the straps precisely, both for height and tension. A backpack that moves around causes chafing; a backpack that’s too tight causes pressure points. You’ll find the right balance when trying it on with the backpack fully loaded.
Are there any special cuts for women?
Yes, and that's no small matter. The specific cuts prevent the pressure points on the chest that often occur with unisex models. If you've already given up on backpacks for this reason, try a model designed for women's body shapes before you conclude that front-carry comfort isn't right for you.
How do I care for my backpack and hydration bladder?
Rinse it out with clean water after every run—pay special attention to this if you’ve run along the coast, where salt can damage the fibers. Dry it in the shade in the fresh air. For the hydration bladder, dry the reservoir and hose separately and in an open position. Cleaning tablets are available for more thorough care before long-term storage.
Can I customize backpacks for a club?
Yes, through KUSTOM. The service is aimed at clubs, associations, and event organizers who want to customize technical equipment with their own colors. The team supports the project from design through delivery, with delivery dates tailored to your season’s schedule.