Outdoor Research Helium Adrenaline Day Pack 20L Review

Lots of mesh helps the Outdoor Research Helium Adrenaline Day Pack 20L expel heat, though it’s tricky to find the best fit at first.

Our Verdict

7.6 /10
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  • Harness system’s mesh effectively expels warm air
  • Fairly lightweight for a well-padded bag
  • Shoulder straps pockets are convenient quick-stash spots


  • Strap length hard to adjust
  • Congested main compartment takes practice to pack efficiently
  • Shoulder strap pockets rub against the biceps as you walk

Technical Details

87 %

Carry-on Compliance

View 126/145 Airlines

35 %

Like the Look

Polled on Instagram

  • Capacity


  • Weight (oz)

    16.1 oz (456.4 g)

  • Dimensions

    18.1102 in x 10.2362 in x 7 in (46 x 26 x 17.8 cm)

  • Notable Materials

    Nylon, Ripstop Nylon, YKK Zippers, Polyurethane, Woojin Hardware

  • Manufacturing Country


  • Warranty Information

    Infinite Guarantee

Buying Options

Outdoor Research Logo
Moosejaw Logo
Backcountry Logo
Amazon Logo

Full Review

The Outdoor Research Helium Adrenaline Day Pack 20L almost needs no introduction because of its self-explanatory name. It’s an outdoor-focused daypack with expected features like lightweight but durable fabrics, a heavily-meshed and padded harness system, and provisions for attaching a hydration bladder. It even has the hooded drawstring cinch closure many other outdoor-focused backpacks have.

Outdoor Research Helium Adrenaline Day Pack 20L Outdoor
Outdoor Research Helium Adrenaline Day Pack 20L | This bag just shouts adventure.

Consequently, the top-loader layout, combined with a fairly modest 20-liter capacity, means it’s fairly easy to congest the interior. Organization-wise, the Helium Adrenaline Day Pack is pretty well-equipped, with shoulder strap pockets, a large front pocket for jackets, and an interior zip pocket for other small accessories. However, learning to pack it proficiently takes time, given the bag’s layout, features, and soft structure.

External Components

Based on looks alone, there’s no hiding the fact that the Helium Adrenaline Day Pack is made for the outdoors. With its loud and in-your-face logo, neon green straps, and capsule-like shape, you just know it’s up for an adventure. It probably isn’t the most subtle backpack to bring to a business meeting the same day you hit the trail, though. But if the meeting was with fellow trekkers, they’d probably be as enthused with the looks as you are. It’s not all style with no substance, that’s for sure.

Outdoor Research Helium Adrenaline Day Pack 20L Brand
Outdoor Research Helium Adrenaline Day Pack 20L | It’s a large logo, but we like it.

With a brand name like “Outdoor Research” posted front and center, you can expect that the Helium Adrenaline Day Pack has the appropriate rugged materials. The outer shell is a mix of 210-denier mini diamond ripstop nylon and 30-denier ripstop Pertex Shield Diamond Fuse nylon. Granted, those denier values look paltry compared to the 1680-denier CORDURA® Ballistic Nylon of some travel backpacks. However, bear in mind that you’ll be carrying Helium Adrenaline Day Pack on lengthy dirt trails. As such, lightness is just as important as abrasion resistance.

We took the Helium Adrenaline Day Pack on one such trail, and we’re happy to report that everything is still intact and practically blemish-free, thanks to the water-resistant PU coating that lets you wipe off most stains relatively easily. There were no tears or punctures, either. However, if there was, the ripstop fabric would isolate it with its grid-pattern reinforcement.

Outdoor Research Helium Adrenaline Day Pack 20L Tripod
Outdoor Research Helium Adrenaline Day Pack 20L | These side straps can’t be tightened as much as we want to.

Around the sides are those neon green straps we mentioned earlier. These are for your tools, like ice axes, travel tripods, or walking sticks. There are two on each side, though quantity isn’t really their main issue. No matter how tightly we adjusted them, we couldn’t make them cinch a walking stick as firmly as we wanted, just firmly enough not to lose them.

You may have noticed that there are no water bottle pockets, which feels like a missed opportunity. After all, a travel water bottle is probably the first piece of gear anyone would bring on a thirst-inducing trek. That said, you can attach a hydration bladder inside, and that’s the alternative solution, in case you were wondering.

Outdoor Research Helium Adrenaline Day Pack 20L Carry Handle 2
Outdoor Research Helium Adrenaline Day Pack 20L | It doesn’t brush against the neck.

There’s also a top handle located between the shoulder straps. There’s not much to say about it other than it’s a handy standard feature most backpacks have. You can use it to hang the bag behind a restroom stall’s door (if you’re lucky enough to find one with a hook). Or if the trail’s rest stop is muddy, use the handle to hook it on a nearby tree’s low-hanging branch.

The Helium Adrenaline Day Pack is neither too big nor too small for an outdoor daypack. It is quite portable at 20 liters, though much of the credit goes to its beefy harness system. The shoulder straps alone pack a ton of dense and cushy padding, and so does the back panel. Equally important is the mesh that covers both the straps and the rear panel, which allows hot air to flow more freely.

Outdoor Research Helium Adrenaline Day Pack 20L Material
Outdoor Research Helium Adrenaline Day Pack 20L | The mesh helps a lot with expelling heat.

Less free is the adjustment to the sternum and the shoulder straps. No, we don’t mean they cost extra, just that their length is rather hard to adjust. The straps are very snug against the plastic adjuster, so you’ll have to set the adjustment right out of the box and hope you never have to do it again. A good side effect of that stiff adjustment is that the straps don’t get loose over time as you move along—desirable for an outdoor-themed backpack.

Outdoor Research Helium Adrenaline Day Pack 20L Strap Keeper
Outdoor Research Helium Adrenaline Day Pack 20L | The adjusters are very tight.

There’s also the removable hip belt in case you need extra support. It’s a thin strap with no padding and a central buckle. We don’t really find this strap necessary on relatively light treks. However, if you’re doing activities with a lot of emphasis on movements, like biking or jogging, then a hip belt like this is super handy.

Fit Notes

Outdoor Research Helium Adrenaline Day Pack 20L Side By Side
Left: Lauren Maternowski, Height: 5’6” (168 cm), Torso: 16.5” (42 cm) | Right: Ahmad Mesto Kirdi, Height: 6’1″ (185 cm), Torso: 18” (46 cm)

We really dig how easily the harness system expels warm air, thanks to all of the mesh material. It’s one of those factors that you can’t see happening, but you definitely feel it once you’re out and using the backpack. That said, the Helium Adrenaline Day Pack’s harness system does have its shortcomings.

Outdoor Research Helium Adrenaline Day Pack 20L Strap
Outdoor Research Helium Adrenaline Day Pack 20L | There’s also a hip belt in case you need extra support.

As we’ve said, adjustments are particularly difficult, though it’s important that you do. See those large zippered pockets on both shoulder straps? Once those are full, they can rub on your biceps as you walk. Playing around with the adjustment can minimize how much they chafe. The fit feels very ergonomic once you’ve dialed all the straps in, though. The back panel curves against your back effectively, and the straps’ padding feels well-cushioned even with a fully packed-out main compartment and a full day of hiking.

Inside The Backpack

The shoulder strap pockets mentioned above are the primary way to get quick access to everyday carry items. As much as we don’t like them rubbing on the arm while walking, they are handy for keeping small gear readily accessible while you’re wearing the bag. Each pocket also has a unique design.

Outdoor Research Helium Adrenaline Day Pack 20L In Use
Outdoor Research Helium Adrenaline Day Pack 20L | An iPhone 13 fits, though the zipper won’t close completely.

The pocket on the left shoulder strap (right when you’re wearing it) is sealed by a zipper for small loose gear like a mini tripod, a chapstick, or snacks. Unfortunately, while it can technically fit a cased iPhone 13, you can’t fully close the zipper if you do. The same goes for the other pocket. Though the right one has an open top (and a stretchy gusset), you still can’t zip it completely if you put in an iPhone 13. Smartphones aside, these pockets are still very useful for storing small items, and making them bigger might impact comfort anyway, for reasons we’ve already discussed.

There’s a large drop pocket adjacent to the main compartment for anything bulky, like a packable jacket. Access is a bit tricky since you have to undo the metal G-hook securing the top of the bag. A quick note about this G-hook: the corresponding elastic loops feel like they’ve gotten loose over a few weeks of testing. They still work, but we’re not quite sure if they’ll get looser over time.

Outdoor Research Helium Adrenaline Day Pack 20L Interior
Outdoor Research Helium Adrenaline Day Pack 20L | The interior thankfully uses a light gray liner.

Once you’ve undone the G-hook, you can now access a large, cavernous space just in front of the main compartment. Anyone going on a hike probably wants to pack something bulky like a jacket, towel, or heavy-duty gloves, and this is a prime location for them. Conversely, since it’s a large, dark, catch-all pocket, stowing small gear inside is not advisable unless you first put them in an organizer, like a tech pouch.

While it is a spacious pocket, it can still impact how you pack the main compartment. In our testing, we found it tricky to put back items in the main compartment if the front was still stuffed with a jacket. In other words, pack the main compartment first, then the front pocket, if you want it done easily.

The combination of a G-hook and a drawstring cinch for the main compartment isn’t the fastest for accessibility, but it makes sense for weather resistance. Thankfully, the Helium Adrenaline Day Pack’s 20-liter size and light gray interior make interior visibility relatively good. However, items still stack up, and hanging a hydration bladder at the back can make packing even trickier. We recommend attaching your hydration pack first before loading up the rest of your gear.

Outdoor Research Helium Adrenaline Day Pack 20L Kindle
Outdoor Research Helium Adrenaline Day Pack 20L | It’s a fairly tight compartment once the front pocket is packed and a hydration bladder is attached.

Packing cubes are the way to keep gear organized since space is fairly constrained. Apart from a potentially packed-out front pocket and hydration bladder congesting the interior, the bag’s relatively soft structure can also hinder packing. This is a side effect of the bag’s light fabric, so we’ll let you decide if the weight savings is worth the tradeoff in structure.

Other means of organizing gear include a zippered pocket near the hydration bladder loop. It’s big enough for the small loose items you don’t need frequent access to (otherwise, put them in one of the shoulder strap pockets). There’s also a built-in key clip for your house keys. Keep in mind that this pocket can get obscured by bulky gear in front of it, so you may struggle to get your keys out once you get to your door.

Outdoor Research Helium Adrenaline Day Pack 20L Hydration Kit
Outdoor Research Helium Adrenaline Day Pack 20L | There are two holes for routing your drinking tube, but we used the cinched opening instead.

At the back is a laptop sleeve that can fit a 13-inch MacBook. However, its primary purpose is storing a hydration bladder, as hinted by the buckled loop at its top. Routing a drinking tube is fairly straightforward. There are two pass-throughs near the top side straps: one on the right and one on the left. Unfortunately, using either pass-through routes the tube in a way that it lands on the shoulder weirdly. The good news is that you can also route your drinking tube through the cinch, making it easier to thread it through either shoulder strap’s attachment loop.

Usage Timeline

Initial Usage

Condition: Excellent

  • Materials feel lightweight and durable
  • Interested to see if the shoulder strap pockets cause chafing
  • Access seems like it could be slow with the cinch-top closure and lid
2 Weeks of Use

Condition: Excellent

  • Super cushy mesh on the shoulder straps
  • Packing the pockets efficiently takes some practice
  • Decent amount of structure considering the lightweight materials
  • Dual-adjustment shoulder straps take some finesse but hold their adjustment
By Lauren Maternowski
Created June 6, 2023 • Updated June 6, 2023
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