Product Description
You've felt it before: the vest that bounces every stride, the straps that dig in around mile 10, the constant mental tax of fighting your gear when your focus should be on pace. Most athletes accept it as part of the deal. Here's what most athletes don't realize: your hydration vest isn't supposed to be something you manage. The right one disappears and stays there.
The Nathan AeroZip 1L Unisex Hydration Race Vest is the exact carry system trusted by marathon runners and ultramarathoners who refuse to let hydration cost them time, energy, or aerodynamics.
- Aerodynamic fit that locks to your body. Perforated four-way stretch fabric wraps your torso like a second skin, stable without compressing, locked in without restricting breathing or arm swing.
- Two flasks, zero fumbling. Two oval-shaped 17oz Nathan x HydraPak soft flasks contour your chest for a flatter carry than round bottles. Pull one mid-stride, drink, tuck it back, 34oz always within reach.
- Zip on, zip off in seconds. A full front locking zipper replaces the pullover fight at race morning. Side elastic toggle cords let you micro-adjust fit precisely to your torso.
When a vest moves independently from your body, your core compensates on every stride, wasting energy you'd rather put into pace. The AeroZip's body-contouring fit eliminates that movement. Oval soft flasks collapse as you drink, removing the air pocket that causes sloshing. At 4.8oz without flasks, your body stops registering it as gear within the first mile.
Before your race: Fill both 17oz flasks, one water, one electrolyte mix — and load your mesh pockets with gels in order of use. Everything organized, nothing to think about mid-race.
On course: Pull a flask one-handed, drink, return it without breaking stride. Repeat every 15–20 minutes.
Pro tip: Dial the side toggle cords at home before race day so the vest sits flush against your torso. Two minutes once, locked in every time after.
Ironman athletes and ultramarathon runners who've switched from rear bladders and hip belts report the same thing: the front-carry system is faster, the fit stays put, and the vest disappears by mile three. These are the athletes who stop experimenting with hydration because they've found something that works.
This isn't just another hydration vest. This is 34oz of on-board fluid in 4.8oz of gear, so your only job on race day is to run fast.
What Is the Nathan AeroZip 1L Hydration Race Vest?
The Nathan AeroZip 1L Unisex Hydration Race Vest is Nathan Sports' precision-fit, ultralight hydration vest built for marathon, trail, and ultra racing. Previously known as the Nathan Stealth 1L, the AeroZip is the updated successor with refined specs: a full front locking zipper entry, two oval-shaped 17oz Nathan x HydraPak soft flasks, perforated four-way stretch woven fabric, and side elastic toggle cords for micro-fit adjustability. Total storage capacity is 1 liter / 61 cubic inches. Weight is 4.8oz / 137g without flasks and 7.6oz / 216g fully loaded.
We've stocked a lot of hydration vests at The Feed, and the question we always come back to is: does it actually stay put? A vest that bounces or shifts mid-race is costing you — not just in comfort, but in the subtle energy tax your core pays to compensate. The AeroZip nails the thing that matters most. The fit locks in. The two-flask front carry is genuinely faster than anything on your hip or behind your back. And the front zip entry is one of those details that sounds small until you've wrestled a pullover vest over your head at mile 0 of an Ironman run. This is the vest I'd reach for.
— Matt Johnson, Founder, The Feed
What You Get:
- Nathan AeroZip 1L Unisex Hydration Race Vest
- Two 17oz / 500ml Nathan x HydraPak oval soft flasks
- Four expandable power mesh front pockets
- One zippered valuables pocket
- Side elastic cords with toggle locks
- Full front locking zipper closure
- Available in S, M, L, XL
For gear that arrives damaged or falls under the manufacturer's warranty: Please send a photo of the damage or error message to hello@thefeed.com. We will either help process a claim for the product and a replacement product or store credit will be provided, or we will direct you towards the correct place to make a warranty claim for the product. For returns on gear that you have used, we follow the manufacturer's instructions for satisfaction guarantees. This is specific to each gear product, terms and conditions may change.
Nathan AeroZip 1L Unisex Hydration Race Vest FAQ's
Everything you need to know about Nathan AeroZip 1L Unisex Hydration Race Vest.
The AeroZip 1L is a precision-fit, ultralight running vest designed for marathon, trail, and ultra racing. It includes two 17oz oval-shaped soft flasks, a full front locking zipper, four expandable mesh front pockets, and a zippered valuables pocket. Total on-board hydration is 34oz across two independently accessible front flasks.
The AeroZip 1L is the direct successor to the Nathan Stealth 1L — same core race vest philosophy, updated with a full front locking zipper, oval HydraPak soft flasks, and perforated four-way stretch fabric. If the Stealth 1L was your vest, the AeroZip is your next one.
Start with Nathan's size chart using your chest measurement and select S, M, L, or XL. Once on, use the side elastic cords and toggle locks to micro-adjust until the vest sits flush against your torso — no bounce, no gap, no pinch. It should feel snug but never restrictive on your breathing.
Two 17oz / 500ml Nathan x HydraPak oval soft flasks. They're shaped to contour your chest for a flatter fit than round flasks and collapse as you drink to eliminate sloshing. Total fluid capacity: 34oz across both flasks.
Hand wash or machine wash gentle cycle, cold water, air dry only. Heat degrades the stretch fabric and DWR coating. Rinse soft flasks after every use and air dry with caps open before storing.