My Go-To Gym Bag Is Just $24 for Prime Day

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Prime Day 2025 is here from Tuesday, July 8 to Friday, July 11, and Lifehacker is sharing the best sales based on product reviews, comparisons, and price-tracking tools. 

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New to Prime Day? We have a primer on everything you need to know. Sales are accurate at the time of publication, but prices and inventory are always subject to change.

My favorite duffel bag is on sale this Prime Day, and it’s one of the best (and most affordable!) gym bags out there. I’m talking about the Adidas Defender. It comes in different sizes; I own the small (38 liter), which is on sale for just $24 in black today. Prices vary by color, and by whether you’re looking at the 4.0 or 5.0 version, but you can also get the medium (66 liter) for $27, or the large (110 liter) for $33, to name a few. These bags normally run $40 to $55 depending on size.

adidas Unisex Defender 4.0 Gym Duffel Bag, Black/White, Small (38L)

$24.00

$40.00
Save $16.00

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Get Deal

$24.00

$40.00
Save $16.00

I’m not kidding when I say it’s my favorite gym bag. I bought mine six years ago. I’ve used it almost daily since then, and it still looks brand new. (Minus the purple ink that I spilled in one of the inside pockets, but I was able to get almost all of it out.)

This is my regular duty gym bag, and here’s what I normally carry in it: 

• A pair of Nike Romaleo 3 weightlifting shoes in the side pocket with the mesh panel

• A wealth of snacks and electrolytes in the other side pocket, including a sack of fun-size Sour Patch Kids to share with my friends.

• Small items like my inhaler, lip balm, and a phone charging cable in the little front zipper pocket

• A leather belt (Pioneer Cut 3” suede single-prong), which I keep in the main compartment, curled around all the rest of my stuff

• Also in the main compartment, inside the belt: two pairs of knee sleeves, two pairs of knee wraps, a resistance band for my shoulder warmup routine, a water bottle, a training journal, and probably a dozen other things I’ve forgotten about, but they are in there when I need them, if I can find them, probably.

And this is the small bag! There’s even enough room to add a lunchbox and/or a packing cube with a change of clothes when I go to competitions. The only place it feels cramped is in the shoe compartment: If I had bigger feet, I’d probably appreciate the medium bag.

Credit: Beth Skwarecki

The medium is also a handy size for non-gym purposes. Our managing editor, Meghan Walbert, snagged two mediums for her teenage sons during a previous sale. When I asked her about them today, she said “my kids just took them to Ohio and will be packing them again tomorrow for the shore.” When they were on sale last year, I checked in then as well and she sent me a photo of them packed for a road trip. These bags are durable enough and handy enough we can’t quit them, gymgoers and travelers alike.

I’ll add that if you want to use these duffels as a travel bag, you may want to pick up some packing cubes to use with them. May I suggest a two-pack of the U+U clean/dirty packing cubes that are on a little sale ($2 off) today? Each one has a zipper on the back to put your dirty laundry in for the trip home (so the two-pack will give two people each room for their clean and dirty clothes—or one person can have a cube for their gym bag and a cube for their suitcase, which is how I use them.) 

Looking for something else? Retailers like Walmart, Best Buy, and Home Depot have Prime Day competition sales that are especially useful if you don’t have Amazon Prime.

• Walmart’s Prime Day competition sale begins at midnight on July 8 and will include deals up to 50% off. It’s an especially good option if you have Walmart+. 

• Best Buy’s Prime Day competition sale, “Black Friday in July,” runs through Sunday, July 13 and has some of the best tech sales online. It’s an especially good option if you’re a My Best Buy “Plus” or “Total” member.

• Home Depot extended its 4th of July sale through at least July 9, competing with some amazing deals of its own. It’s an especially good option if you’re looking for power tools, appliances, or outdoor equipment.