Best Running Vests 5L-6L: Four Practical Options for Trail and Ultralight Racing

Introduction

After testing four hydration vests in the 5L to 6L range over a full season, the takeaway is clear: they are all genuinely well-designed. Rather than declaring a single winner, the real differences emerge in fit, pocket layout, and how each vest handles the small details that matter during long runs. All four sit within roughly $40 of each other at full retail price, and all perform extremely well once you’re on the trail. The choice comes down to matching the vest to your personal habits and preferences.

Tantrums Crest 6

The Tantrums Crest 6 retails for $180 USD and represents a newer entrant to the market. Tantrums soft-launched this pack in time for elite runners to use it at major races like Western States, and it has generated positive feedback since. The vest is designed with racing in mind: it is lightweight, breathable, and prioritizes easy access over security.

The Crest 6 ships with two 600ml soft flasks from Hydrapak, which is larger than the standard 500ml flasks found on most competitors. This is a genuine advantage for runners who prefer to avoid bladders. The rear compartment is spacious and designed to accommodate a bladder with a dedicated hook, plus a large pass-through for spare clothing or a horizontal flask. The front pockets lack zippers but are easy to access, which suits racing but may concern those running longer training efforts where security matters. A small zippered pocket on the left shoulder provides storage for keys or other valuables, and the included whistle tucks away in a dedicated stash pocket.

The vest is compatible with Salomon’s quiver system via small loops on either side, and poles can be attached along the bottom of the back using included straps. One sizing note: the Crest 6 runs small. A medium rubbed the neck, so sizing up to a large provided a much better fit. If you are between sizes, going up is recommended.

The main trade-off is availability. Tantrums is a small, bootstrapped company, and stock can be limited. Long-term durability and warranty support remain unknowns at this stage, though the vest itself is well-executed.

NNormal Race Vest 5L

The NNormal Race Vest 5L is currently listed between $100 and $140 USD, and may be on sale as a newer version approaches. This vest shares several design cues with the Crest 6, including the same sternum strap clips, but differentiates itself with thoughtful innovations.

The standout feature is a waterproof rear compartment, accessed via zippers on either side. This is unique in the 5L category and allows you to store spare clothing or gear while keeping it dry. The downside is that the zippers can be fiddly to operate, especially with gloves, and often require two hands to locate and open. The front pockets are narrower than on some competitors, which actually works in your favour if you carry a phone: the taller, narrower design keeps the phone more secure and prevents it from bouncing around inside the pocket.

The vest comes with two 500ml flasks secured with loops, plus unique bungee cords designed to cinch down the pockets. There is no bladder hook or hose pass-through, which is fine if you prefer flask-only hydration. Pole attachment uses straps along the bottom, and the vest is not compatible with the quiver system, though NNormal offers a run belt with similar pole straps if you prefer to offload weight to your hips.

Fit is excellent with minimal bounce, though the vest runs small across NNormal’s entire apparel line. If you typically wear a medium, consider sizing up to a large. The vest is well-designed and shows promise for future iterations, particularly any larger capacity options that may be in development.

Adidas Terrex Techrock 5L

The Adidas Terrex Techrock 5L retails for $160 USD but is currently available on clearance at several retailers for as little as $100, suggesting a newer version may be coming soon. This is the most distinctive vest of the four in terms of fit and design approach.

The Techrock features reinforcements on the front that give the pack structure and significantly reduce bottle bounce. These reinforcements also make the zippered pocket on the left side easier to access, and this is the only vest in the group with a front zippered pocket, making it ideal for storing valuable items like AirPod cases. The rear design is simple and lightweight, with a large pocket and easy-access pass-through, but no bladder compatibility.

The vest comes with two 500ml flasks secured with orange loops, plus two narrow side pockets for gels or a phone. Like the NNormal vest, these pockets are taller than they are wide, which keeps a phone secure and prevents bouncing. An iPhone 15 Pro fits perfectly; a Pro Max might be too wide. A small interior pocket with a key loop sits inside the pass-through. Pole attachment uses straps along the bottom, and the vest is not compatible with the quiver system.

In a size medium, the Techrock fits perfectly with no desire to size up. The reinforced design and narrow pockets make it an excellent choice if phone security and front pocket access are priorities. The included whistle can be removed if it interferes with flask replacement.

Salomon Advanced Skin 5

The Salomon Advanced Skin 5 retails for $145 USD and represents the benchmark against which other running vests are often compared. Salomon has been refining vest design for years, and the Advanced Skin line has consistently been the most versatile and stable option available.

The Advanced Skin 5 is slightly heavier and less breathable than the other three vests due to extra fabric in strategic places, but this translates to superior fit stability and versatility. The rear features two main pockets: one closer to the back designed for a bladder, and a second for general gear. A large zippered compartment provides secure storage, though a dedicated jacket pocket that existed in older versions has been removed. The pass-through is smaller than in previous iterations, a change that reflects years of design refinement based on customer feedback and warranty claims.

The front pockets are the largest of any vest tested, rivalling the Crest 6 in capacity. A zippered pocket on the left provides secure storage for valuables. The Advanced Skin 12L version has two zippered pockets, and it would be beneficial if the 5L offered the same, though the extra weight and zipper durability concerns likely explain the current design.

One practical consideration: heavier items like phones tend to slide down and bounce around in the large pockets. Many runners end up placing the phone in an empty flask pocket instead to keep it secure. The vest comes with two 500ml flasks, a whistle, and a key hook. It is fully compatible with Salomon’s quiver system and includes straps for pole attachment along the back or vertically at the front.

Fit is excellent, and the vest is the most stable of the four tested. Sizing note: if you have worn a medium in the past, consider moving to a large, particularly if you have a larger chest and shoulders. The Advanced Skin 5 remains the most versatile option in this category and the best choice if you can only own one vest, though the Advanced Skin 12L is worth considering for its extra storage and dedicated jacket pocket.

Choosing the Right Vest for You

All four vests solve the core problem of carrying hydration and gear during trail running. The differences are subtle but meaningful. Prioritize fit first: a vest that disappears during a run is the right one. Second, consider how you prefer to carry poles or a bladder, if at all. Third, match the pocket layout to your habits on the trail. Do you need secure phone storage, or do you prefer easy access to gels? Do you want a waterproof compartment, or is a simple pass-through enough?

For racing and ultralight performance, the Tantrums Crest 6 and NNormal Race Vest 5L are excellent choices, though availability and sizing quirks apply. The Adidas Terrex Techrock 5L excels if you value front pocket access and phone security. The Salomon Advanced Skin 5 remains the most stable and versatile option, particularly if you plan to use the vest for both racing and longer training runs.

Real differentiation in hydration pack design emerges once you move beyond the 10L to 12L range into packs designed for longer races, multi-day efforts, and fast-packing. Within the 5L to 6L category, there is honestly no wrong choice.

Conclusion

Testing these four vests over a full season confirms that the 5L to 6L hydration vest category has matured. All four options are well-designed, perform reliably, and sit within a narrow price range. The best vest is the one that fits your body, matches your carrying preferences, and becomes invisible once you start running. Consider trying on multiple options if possible, and do not hesitate to size up if you fall between sizes. Your comfort on the trail depends on it.