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How to Choose a Hydration Pack for Running

The Sense Ultra is snug and secure even when running hard.
Photo: Katy Scott
By Brian Martin ⋅ Review Editor
Monday July 13, 2020
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If you've found yourself here, you're likely looking for the best way to carry your water, gear, and food for long-distance running missions. There are many hydration packs for running on the market, and it can be hard to know what to look for. We dug into the best packs around, identifying their best features and constructions. Here, we explain the ins and outs of running packs and how you can find the one best suited for your needs.

What is a Running Hydration Pack?

Also known as a running vest, a hydration pack for running carries water, food, and emergency essentials that you can't leave behind on a long run. They are designed specifically for long trail runs, adventure runs, or races where a simple handheld water bottle and a gel or two will not suffice. Larger volumes are sometimes considered for fastpacking as well. Unlike many other small hydration systems, these models have a form-fitting design that helps keep the pack in place during the up and down bouncing of running. Running vests typically have dual chest straps to secure them in place and do not have waist belts. They are also designed to be very sleek and lightweight because if you're running in the mountains for 20 miles, the last thing you want is to be slowed down by a heavy pack. They all have pockets on the chest straps or sides to store food and accessories within easy reach without needing to take the whole thing off. Taking the pack off takes time, and while you're running, the last thing you want to do is stop.

Intended Use

You may be wondering why there are so many different shapes and sizes of running packs. The field is muddied with dozens of products claiming to be the lightest, easiest to use, and most comfortable, but how do you know what to look for? There are so many different ways to use these packs, from marathon races to training runs, mountain scrambles to all-day adventures. It's important to determine exactly what you'll be using your pack for so that you can decide which metrics are most important. Are you doing a long race with aid stations every ten miles, or are you self-supported on a big day with no resupplies? Fortunately, with so many packs out there, there's something for everyone and every mission.

Even though we had a few issues with the Duro, overall it performed...
Even though we had a few issues with the Duro, overall it performed well on the trails.
Photo: Brian Martin

We enjoy the outdoors, running, and not being restricted to shorter outings or having to carry a bulky, ill-fitting backpack. This is where figuring out where you will spend the majority of your time running is key to finding the right running vest. If you spend 90 percent of your time running short, five miles or less, trail runs or supported events with frequent resupply options, something light, efficient, and affordable such as the Best Buy Award-winning CamelBak Circuit might do the job without adding a lot of superfluous features. If you spend more than 20 percent of your time out in the mountains running without support, it's critical to get a pack that will haul required equipment comfortably with room to spare. If your pack is maxed out, it will detract heavily from your comfort and won't allow you to deviate from your usual outings by adding more equipment.

More than likely, you fit into the category that our testers fit into. You get out on trails, run in the city, and occasionally go for big mountain adventures that your family always assumes you will die on and ask, "Is this a good decision?", "Where exactly are you going again?", and our favorite, "Hey did you know someone was just attacked by a mountain lion there?" If this sounds like you and your overprotective family, getting a running pack that can accommodate all types of adventures comfortably might be a good avenue. The Salomon ADV Skin 12 Set for men, and the Nathan VaporHowe 2.0 12L for women, are great examples of do-anything products, as they can hold tons of equipment and expand their water capacity, offering a soft buffer between the mountain lions claws and your back.

Our basic emergency kit, jacket, ibuprofen, tape, bandaging, and...
Our basic emergency kit, jacket, ibuprofen, tape, bandaging, and some food easily fit into the main rear compartment of the ADV Skin 12. This allowed us to reserve the easily reachable front pockets for items we are constantly using such as food and our iPhone which we use for media/Strava and heart rate monitoring.
Photo: Brian Martin


Running for extended periods can be uncomfortable. A bouncy, poor-fitting, and improperly packed running vest could be the straw that dashes your FKT dreams upon the rocks of despair. The reason we suggest looking at comfort before the details of what type of hydration system (Bladder, Chest Mounted Hard Bottle, Soft Flask) is because it is an indicator of how important comfort really is. If your pack isn't comfortable, you're not going to wear it, and thus the type of hydration system won't matter. There are several factors to consider when assessing the needed comfort of a running pack.

Ease of Fit Adjustment

Throughout your run, you will consume your food and water and use supplies contained within your running vest. As these vests are snug and designed to minimize bounce as you run, having the ability to quickly and easily adjust the vest as things come out or go in is critical. You don't want to spend ten minutes adjusting things when you're out on a run. The Salomon Advanced Skin 12 has a superior fit adjustment system compared to most, and the women's Nathan TrailMix 7L has unparalleled side adjustments for an awesome fit no matter your shape.

This pack is super adjustable, with two lateral straps and two front...
This pack is super adjustable, with two lateral straps and two front straps to help you find a great fit.
Photo: Lauren DeLaunay

One Size Fits All?

There's no substitute for actually trying on a vest. This will let you determine if it will adjust and contour properly to your body. If you are ordering a vest, make sure the provided fit chart lines up with your proportions, as an ill-fitting running vest can be a bigger hindrance than a help. Many of the one-size-fits-all running vests sit high on the chest and have fewer fit adjustments. While these are some of the most comfortable vests for our testers, they have the potential to be ill-fitting for some people. There are more and more vests on the market with at least two sizes available, which can further complicate the process — make sure to examine fit guideline charts closely before you buy!


As you run, there will be some bounce with any vest. Long story short, two particular designs seem to minimize excessive bounce. Flank straps with an equalized V system seem to work quite well as do vests that hug the entire body.

Dual cinch straps allow you to keep the load secure in the large...
Dual cinch straps allow you to keep the load secure in the large back pocket. This design feature is critical for your sanity if the sound of bars and wrappers bouncing around for hours bothers you. Our testers loved how the vest-hugging effect of this model kept pack bounce to a bare minimum.
Photo: Brian Martin


Another critical aspect of comfort is how breathable your running vest is. Early running vest designs had much less breathable material than is available today. For example, the Nathan TrailMix and and Ultimate Direction FKT have see-through mesh material for the shoulder straps and back panel. While this doesn't eliminate the sweat problem, it sure does help. Some models use a "micro monofilament" material as an ultra-breathable mesh for straps on sides and shoulders. The Salomon ADV Skin 12 is also comprised almost entirely of mesh material making it one of the most breathable running vests we tested. The downside of all this breathability is even a light rain shower will permeate the pack. But, unless you need a water-resistant running pack, look for these materials that increase the breathability of your pack — you'll thank yourself later.

A closeup of the micromonofillament. It's completely see-through...
A closeup of the micromonofillament. It's completely see-through mesh material. It proved to be durable, comfortable, and highly breathable.
Photo: Brian Martin

Hydration System

It's a new dawn, and you got options, baby! Back in the day, you had but two choices. Run with the same CamelBak or fanny pack water bottle combo everyone else had, or rely solely on the disposable, environment ending, aid station cups. Now there is a huge selection of hydration systems. For the most part, these fit into three categories. A hydration bladder on your back, soft flasks in chest pockets, or hard bottles also in chest pockets. Each of these has advantages and disadvantages we will hash out below.

We highly appreciate the visible on/off indicator on the mouthpiece...
We highly appreciate the visible on/off indicator on the mouthpiece. Many bite valves don't give such obvious visual cues, making it easy to leave the water wide open.
Photo: Brian Martin

Hydration Bladder

This is the big daddy. If you're heading out for a beatdown in the mountains (or flat trails too!) and don't have many watering holes available, this is probably the option you want. Advantages include having up to two liters of water available at the start, conforming to your back, taking up very little space when empty, padding from a mountain lion attack (eek!), and ease of use (though all types of hydration systems we used were pretty easy). The capacity is really the highlight of a hydration bladder (also often called a reservoir) as they do come with some disadvantages. For the most part, having a big bag of water on your back puts an imbalance of weight in the back of the vest/pack and can add to bounce or discomfort if the vest isn't designed to offset the load. The Ultimate Direction FKT and women's Salomon ADV Skin 8 do a dang good job at hauling weight either in the back, front, or both simultaneously.

The other glaring downside of the hydration bladder is managing the hose. Often this has to be fed through a small channel over the shoulder and clipped onto the chest straps of the pack or vest. While there are some clever solutions out there (we are usually fans of magnetic clips, like that on the Nathan VaporHowe), you will inevitably fiddle with the hose and be frustrated with it at some point. This is usually a small price to pay for a massive reservoir of hydration at your fingertips.

Even with light pressure the bite valve will open. This is a plus...
Even with light pressure the bite valve will open. This is a plus while you're running and a negative when you throw the pack in the back of your car and it leaks all over.
Photo: Brian Martin

Soft Flasks

Over the past few years, this has become "ultra" popular. Get it? Because ultra-marathons. It makes sense; you have squeezie bottles holstered in chest pockets right next to your mouth. They are easy enough to fill and the least annoying to drink out of as you don't have to remove them from the pockets. This also allows you to have different beverages in each pouch, such as plain water on one side and maybe a Tailwind nutrition on the other.

The frustration with soft flasks comes when you try to stuff refilled bottles back into the chest pockets. While some vests are a bit easier than others, none of them are great. Again, it's a small price to pay for the ease and convenience of having those soft flasks perfectly positioned to deliver high-quality H2O. We tested both Salomon and Ultimate Direction soft flasks and enjoyed them both. There were no issues with leakage, though we sometimes wished both had a bit more capacity. If you're in an event or scenario that provides good resupply options, soft flasks are probably the way to go. They're simple, offer you the ability to have different liquids in each, ride well, and because they are small and conform to your body, they don't bounce much.

While this isn't the most adjustable vest, the existing adjustments...
While this isn't the most adjustable vest, the existing adjustments are easy to use and the soft flasks make it extremely comfortable with relatively little bounce while running.
Photo: Brian Martin

Hard Bottles

This seems to be something of a holdover from a past littered with hard plastic bottles. While we didn't mind using them too much, they are significantly less comfortable than both soft flasks and hydration bladders. One huge bonus is how much easier it is to fill something that can stand up on its own. There are times when it feels like filling a hydration bladder requires three hands. A dual hard bottle design also lets you have different options with your hydration choices like the soft flasks.

There is one standout situation where these bottles would be a good choice over the soft flasks, and that's when durability counts. If you're running self-supported through terrain likely to rip and poke at you with briars and branches, the soft flasks could rip. Other than this durability issue, it's hard to think of a time when you would want to run only hard bottles and forego the new soft flask technology.

If you didn't get the fit adjustments just right, the full hard...
If you didn't get the fit adjustments just right, the full hard bottles could clang around a bit.
Photo: Brian Martin


While there are many specialist running vests or packs, there are also quite a few out there that offer some variability in what you can haul along as far as hydration, equipment, and food. The vests that boast an "expandable" water capacity often come with soft or hard flasks in chest pockets and have a sleeve in the back capable of holding a 1.5-2 liter hydration bladder. Vests with this capacity tended to be our favorite for several reasons.

These vests had a better capability to haul both light and heavier loads, and ultimately, at max capacity, we could put on three liters of water at the beginning of our day. Yes, this is heavy starting out, buuuut, you can go a long freakin' way on that amount of water. Just think of the extra weight as training weight. If you choose only to use the bladder or soft flasks in front, the extra space is always nice to hold a running jacket or food.

Getting the bottles in and out is a bit of a pain, but drinking from...
Getting the bottles in and out is a bit of a pain, but drinking from them is a breeze!
Photo: Lauren DeLaunay

Accessories, Pockets, and Weight

There are lots of extras that are going to be specific for each runner. Do you need a pocket capable of holding an iPhone six plus? Do you run with running poles but need to be able to store them on the pack at certain times? Questions like this will allow you to narrow down the accessories that are necessary to aid you on your quest to glory.

A word of caution: if you go all out and get a vest with literally every accessory available but don't need them, it will be cumbersome, heavy, and just unnecessary. Be honest with yourself on what you will be using your vest for. There are so many options out there; trust us, you will be able to find the one that fits your running style and will compliment your needs.

Packed up and ready to race
Packed up and ready to race
Photo: Jenna Ammerman


We listed weight at the end mostly because all of the running vests that have crossed our path have been quite lightweight. There are the outliers on either end of the spectrum, but this factor isn't as important as finding a vest that fits your needs and style of running. If finding the lightest vest available is a priority for you, check out the lineup from Salomon as they have some insanely lightweight vests.

The S/Lab is by far the lightest vest we tested (shown here being...
The S/Lab is by far the lightest vest we tested (shown here being weighed without its included soft bottles). If looking for something on the minimalist side, this is a pretty good choice.
Photo: Brian Martin

The Salomon S/Lab Sense Ultra 5 is a standout as a versatile, lightweight vest. While the fit adjustment is frustrating, once you have it dialed in, you will barely notice you have it on. The material of the vest is almost entirely made of stretchable fabric and allows you to cram quite a lot of equipment in for only having 5 liters of storage.

Our recommendation is to ignore the weight factor until you have narrowed your vest quest down to just a few options. Maybe, just maybe, when you are having trouble picking between a couple of different options, you can factor in the weight and save yourself a few grams.

The Circuit finds a zen like balance between comfort, storage...
The Circuit finds a zen like balance between comfort, storage capacity, and price.
Photo: Brian Martin

Women's Fit

As long-distance running gains in popularity, the number of women demanding products designed for their bodies grows as well. In a market dominated by "unisex" (a.k.a. men's) packs, there are reasons you might want to look into a female-specific pack. While there are definitely fewer women's models out there, the ones we found were excellent, with tons of variety in size and shape.

We had our female testers try out men's models, also, to see if there really was any difference. The answer seems to be in sizing. Men's models are typically fitted for a taller person, and the bottom of the pack sits a little lower on the rib cage. If you're a taller woman, this may be a great option for you, but if you're on the shorter side, it's harder to find a comfortable fit in men's or unisex models. Some of the women's models we tested come in very small sizes, whereas the men's models aren't usually made to fit such small frames. While this is a general rule, every pack fits differently, so we recommend trying on any product you're considering purchasing, no matter the gender.

The biggest difference we found in models with "women's fit" was in the shoulder and chest straps, which a representative from Ultimate Direction confirmed for us. In certain women's models, like the Salomon ADV Skin 8, the arm openings and shoulders were way too tight for our athletically-built female testers. It seems like a "women's" fit may be designed for a more petite build; these female testers found the men's models to be more comfortable in several cases.

The VaporHowe could be a little lighter, but we love its burly...
The VaporHowe could be a little lighter, but we love its burly, comfortable front straps.
Photo: Lauren DeLaunay

Chest Compatibility

There's no doubt about it: our female testers with larger breasts had a much more difficult time finding the right fit in a running pack. One critical factor in finding a comfortable fit is making sure that the front sits in the right place, the center of the breasts, without squeezing them together or pulling them apart. We found that packs like the Nathan TrailMix that have a lot of side adjustment allow the runner to place the pack in just the right spot, whereas models without side adjustment, like the ADV Skin 8, either fit or didn't, with no room for adjustability. It may also be necessary to size-up one size to accommodate larger breasts. We can definitely say that all the women's models we tested will be a bit more difficult to fit on women with larger breasts, so we strongly suggest (as we do with everyone) trying on a few packs before committing. In an ideal world, a women's running pack should be like an extra-supportive bra that helps keep everything in place. Remember: there is no reason to settle for an uncomfortable pack!


First and foremost, examine the type of running adventure you partake in most often. If you head out on big mountain adventures, find a running vest with expandable hydration capacity as well as the ability to store sufficient equipment and food. If you are sticking to more urban environments or supported events, get an appropriately trimmed down running vest that will get you from station to station without weighing you down. Look at outlying adventures as well and try to find a running vest that will compliment your main activity as well as be able to stretch its capacity to your bigger, more adventurous days. If you have specific needs or oddly shaped gadgets, make sure the vest will be able to accommodate those as well. With about a million options on the market, there is a running vest that will seem as if it was made just for you.

The ADV Skin 12 is at home running in deserts as well as high alpine...
The ADV Skin 12 is at home running in deserts as well as high alpine environments. This pack was designed for all-day comfort and the ability to haul everything you need for the day.
Photo: Brian Martin

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