Outdoor Vitals Skyline Fastpack Review: The Fastest Backpack You’ve Never Heard Of

If you're a speed backpacker or mountain runner looking to move farther and faster in the backcountry, the Outdoor Vitals Skyline Fastpack is purpose built for you.

It was like the sensation of taking flight. I was hiking uphill, 8 miles from my planned campsite in Colorado’s Sawatch Range, when I just started running — with all my backpacking gear on my back. And it worked.

I jogged, jumped, power-hiked, and trotted the entire way. It cut the arduous campsite approach time in half. Even more on the way back. I could feel the possibilities opening up; the long, multiday routes more attainable in a jam-packed summer schedule.

It was possible because of Outdoor Vitals’ Skyline Fastpack ($198). It’s like the brand mashed together a small ultralight backpacking pack with a trail running vest for speedy multiday endeavors into the backcountry.

I dove headlong into fastpacking with the new Skyline over 3 months and man, are my legs tired.

In short: Outdoor Vitals’ New Skyline Fastpack is everything you love about the brand’s ultralight backpacks, but faster. New from the ground up, the Skyline essentially combines a lightweight (24-ounce) backpack and a trail running vest. The result? A streamlined, ultralight backpack that runs, scrambles, and traverses like very few others on the market — if you’ve got the lightweight gear to match it.

Fastpacking is about as niche as you can get in the already niche ultralight backpacking world. It’s really a blend of two sports — adventure trail running and ultralight backpacking. As you can imagine, it comes with its own cornucopia of ultralight fabrics, esoteric doctrine, and specialized gear.

You may share the skepticism that I harbored before going full fastpack. Even if I did have a bunch of ultralight gear, how on earth could I run with 15-25 pounds on my back? Strong legs are a prerequisite. But the bigger difference comes down to packing strategy, which is only as good as the pack that will carry it.

Enter the Outdoor Vitals Skyline Fastpack. This ultrafast, hyperlight backpack is designed to carry up to 20 pounds quickly over long distances.

You may not have heard of Outdoor Vitals until recently when GearJunkie declared its CS40 backpack one of the best ultralight backpacks in the game. Most of the brand’s products are at or near the cutting edge of this category, mainly in the ultralight realm. And it’s got a few other tricks up its sleeve.

Fastpacking isn’t exactly new, but specialized packs are a relatively recent phenomenon. Those on the market take one of three harness approaches: typical backpack straps, a running vest-style harness, or a hybrid of the two.

The Outdoor Vitals Skyline Fastpack takes the hybrid route. Essentially, it’s a trail running vest with a lightweight hip strap that’s not designed to support much weight, but rather to keep the pack stable.

The vest-like shoulder straps are thoughtfully crafted and fit comfortably, even with a decent amount of weight in the pack. They also accommodate two included 500mL Hydro Flask bottles and 1-2 days’ worth of snacks in an additional zip and stretch pocket on each strap.

A simple buckle system keeps things snug up front. Adjustable equalized side straps allow the user to customize the fit. This duo, combined with two sizing options, also means that the Fastpack will fit a variety of body types.

The crux of moving fast with a big pack is often the bounce factor. Considering that Outdoor Vitals doesn’t produce a running vest and this is its first fastpack, it’s clearly done its homework. I found that the pack carried comfortably. The bounce was minimized, and I could easily find a sustainable rhythm.

The shoulder straps started to chafe my collar bones slightly after about 8 miles with a full pack. Thankfully, I was able to mitigate it by dialing in the fit more thoughtfully with the front buckles and side adjusters.

All of the pack’s straps are fixed and non-stretchy. On my wishlist would be the slightest amount of elasticity, particularly on the adjustable underarm straps that would help absorb even more bounce.

It would also allow some give during heavy breathing when the pack is cinched down. Rab’s new Veil vest is an excellent example of strategic elasticity. That pack’s innovative Mono Mesh fits like a hug.

Overall, though, I’ve been impressed by how little discomfort I’ve experienced given how much friction is generated between a sweaty body in motion and a full backpack riding on the shoulders after 2 to 5 hours of movement.

The 28L pack body is one big roll-top compartment housing a removable water bladder sleeve and a small zip pocket. The 100D Robic nylon diamond ripstop fabric has stood up excellently to typical bushwhacking and fastpacking abuse.

The pack repelled splashed water nicely, though it’s not waterproof (an assumption invalidated the hard way in Minnesota’s Boundary Waters). The fabric does carry a 15,000mm HH waterproof rating, however, which is sufficient to fend off light to moderate rain.

Here’s the thing: My cushy backpacking kit didn’t fit in the Skyline. Even my seemingly spartan mountaineering overnight kit was overkill. And 31 L is a big contraction compared to the 40-50L packs I usually take for one- or two-nighters.

The first time I took the fastpack out, I made some serious cuts. No tent body, downsize the sleeping pad, forget the camp slippers, and cut the camp chair. Drop the fresh veggies. Slash the extra water. And get psyched for freeze-dried meals. Camp pillow? You can pry it from my cold, dead hands.

A sleeping bag is typically the bulkiest thing I take backpacking. It wasn’t until I upgraded to Outdoor Vitals’ own StormLoft Down TopQuilt that I felt that I could fit everything I needed in the Fastpack.

Even dropping from an already packable Western Mountaineering Versalite to the StormLoft made a huge difference in packing volume. It meant I could keep my puffy jacket in there along with a real GORE-TEX rain jacket and some lightweight thermal bottoms.

Shelter is typically the next bulkiest item. My fairly minimal Big Agnes Seedhouse 2 fit in there OK, but fastpacking definitely works better when you’ve got a friend or two to share group gear with. On one trip, I ditched the tent altogether in favor of a bivy sack to save space, which the mosquitos were psyched on.

Once I whittled down my kit, I was impressed with how much gear the Skyline could actually accommodate in such a small package for a couple of nights in the summer. Outdoor Vitals has handy packing and fit guides on its website to help users maximize space.

The outside of the Skyline has a bunch of stretchy “Challenge UltraStretch” pockets that were much appreciated in lieu of a brain. OV claims this gray mesh, a mix of ultra-high-molecular-weight polyethylene (UHMWPE) and nylon, is the most cut-, tear-, and abrasion-resistant stretch mesh on the market. I don’t have a reason to doubt it. UHMWPE is mega-strong — think Dyneema climbing slings, cutting-edge mountain bike spokes, and aerospace tech.

After plenty of complicated bushwhacking and some spicy scrambling, the mesh is looking great. No tears or cuts to speak of. Plus, the high-tension mesh locked the contents in there even when the ride got bouncy.

The UltraStretch side pockets also securely held water bottles as big as 1 L for sections of trail without much water requiring more than the 1,000mL in the shoulder straps. Even when I was running through particularly jostling terrain, I never had a bottle bounce out.

I was particularly fond of the UltraStretch pocket on the bottom of the pack — it’s a passthrough pocket ideally suited to layers you might need on the trail, like a rain jacket.

I brought the Fastpack along for an eclectic mix of different adventures to better understand its versatility. On several occasions, I removed the foam back panel and rolled it up to bring it along as a lightweight packable daypack, which it does well.

The Skyline excelled in technical ridge scrambling around the central Rockies. I was able to pack a helmet, layers, and sticky approach shoes for longer excursions with technical climbing. Packs I’ve used in the past for speedy scrambling, like my Black Diamond Blitz 28, don’t run distances particularly comfortably.

Even high-volume running vests like my Black Diamond Distance 15 don’t typically have the volume to accommodate a helmet, and I’ve had my noggin doinked by enough rock to not leave it at home.

It allowed me to run 5-8-mile approaches and deproaches and have a tight-fitting and compact bag to move precisely through complicated terrain. The bottle pockets had a tendency to get snagged when I wasn’t paying attention, but overall, the Skyline excelled in technical nonroped terrain.

Fastpacking is certainly in the trail running family, but I wouldn’t call on the Skyline to pull double duty as my primary trail running vest. It absolutely works as a speedy daypack, but it’s just overkill for typical trail running.

Even for mountain runners and backpackers, fastpacking is ultra-niche. Outdoor Vitals’ new Skyline Fastpack was designed to fill it.

While it combines elements of packs from different sports, I wouldn’t call the Skyline a true hybrid — it’s far more focused than that. Instead, it’s a purpose-built fastpack that happens to excel at peak bagging, ridge scrambling, and speed hiking.

On top of that, it’s a well-executed product, plain and simple. Fastpackers and adventurers looking to move farther and faster in the backcountry are going to find a lot to like in the Skyline.

Not everybody wants to be an ultralight backpacker. That's OK. Now I just have to convince ultralight backpackers that it's OK. Read more…