The Best Expandable Sling Bag for the Gym & Everyday

Looking for the perfect expandable sling bag that's ideal for both the gym and everyday use? Read on to discover the key factors to consider when choosing the right sling bag to meet your workout needs and daily lifestyle.
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What Is A Sling Bag?

Gym-goers and fitness enthusiasts alike are always on the lookout for the best and most convenient ways to carry their workout gear. This is where the sling bag comes in handy. Sling bags are increasingly growing in popularity due to their comfort, flexibility, and convenience. But what exactly is a gym sling bag, and what advantages does it offer?

A sling bag, also known as a crossbody bag, is designed to be worn over one shoulder, with the bag itself resting on the opposite hip, chest or back. It usually has a long strap that can be adjusted to fit the wearer's body and keep the bag secure.

Sling bags come in various sizes and styles. Smaller sling bags are designed to carry only essential items, such as a phone and wallet, while larger sling bags can hold more items, including a tablet, water bottle, and other everyday essentials, including gym gear. They are often used as an alternative to a shoulder bag, as they offer easy access to essentials while leaving the arms and hands-free for other tasks.

Why Choose A Sling Bag For The Gym?

A sling bag offers a few different advantages to the fitness enthusiast over its bulkier bag cousins. The first being minimal size and bulk, the next being versatility, and the final one being style. 


Size matters when you’re carrying a gym bag. Unless you’re carrying 45lb plates in your backpack on the regular, your gym bag doesn’t actually need to be all that large. The average person will carry a change of clothes, sneakers, a water bottle, and maybe some liquid chalk or resistant bands. The right-sized sling bag can meet all those needs without taking up your entire back seat.

When using a sling bag for the gym, we recommend searching for a bag with a volume of around 5-10 liters of interior storage. That should be enough for clothes, water, and a few other odds and ends. 

The perfectly sized gym sling bag will:

  • Have a compact design that minimizes bulk and maximizes space
  • Be easily carried, even in crowded places, allowing you to move quickly if you need to catch a bus, the subway, or a runaway taxi
  • Have room for all your regularly required gym equipment and clothing
  • Be easy to store in a drawer at work or in the gym locker

With an expandable sling bag you can beef up the form factor to meet your needs. If you need to pack extra running shoes, a few bottles of water or just another change of clothes, an expandable sling bag can adjust to the life you lead.


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A single compartment in a sling bag will work in a pinch, but you really want dividers if you can help it to prevent cross contamination (and losing things). Whether you're carrying your lunch, a phone and an external battery with your workout gear, you'll want to find a bag with compartments and pockets that are well-designed to keep your items secure, easy to access and most importantly, separate. 

Choosing a sling bag with expandable features means choosing a bag that can adapt to you. With a simple zip or the clip of a few buckles, you can turn your minimalist sling into an over-the-shoulder pack with enough room for water bottles, running shoes, a tablet and your gym clothes. An expandable sling’s main advantage is that it gives you the option to carry more items when needed, and it can shrink down when you don’t. 

Beyond that, pay attention to how the bag can be worn. Ideally you’ll get one with a beefy buckle and an adjustable strap, which will allow you to wear the sling bag how you want. That means you can carry it across your back, across your front, or around your waist, or over the shoulder. Being able to move it will help you from getting an achy shoulder or hip from carrying your bag in one place for too long.

A versatile gym sling bag will have:

  • Expandable design which allows for added storage when needed
  • Can be worn on the front, back or side for convenience
  • Suitable for various occasions and activities of daily life
  • Separate sections for various items instead of a single big pocket
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Your expandable gym sling’s visual appeal is a part of its charm. You can get a bag that screams “I’m going to the gym!” at anyone who looks at it, or you can find something that you could use in a multitude of ways, with a wide variety of outfits.

Choose a sling gym bag that expands to meet your needs and is stylish enough to accommodate your regular day-to-day wear. If you typically rock a casual fit, you want to be able to pair your sling bag with jeans, a t-shirt, and some vintage sneakers. 

If you’re a high-powered professional, get a bag that won’t look out of place with a blazer, cute bottoms, and heels or loafers. Look for a style that is great for the office, business meetings, or formal events. 

If you’re a digital nomad or you live in a warm climate, you can go laid-back look, and find a bag that pairs with sandals, oversized sunglasses, and a sundress or board shorts. Seek out a bag with style and functionality that works at outdoor festivals, picnics, or beach days.

And for the big city dwellers, you want to find a bag with an urban look; something that can pair with a denim jacket, black jeans, and chunky boots. Consider hunting for a bag that’s able to move with you as you’re touring the city, going out with friends, or just making a statement.

A stylish gym sling bag should feature:

  • A sleek and modern design that complements your typical outfits
  • Materials, and hardware that matches your look
  • A well constructed body that will last for years and still look good
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What Makes the Knack Sling Bag the Best Sling Bag for the Gym?

The Knack Expandable Sling Bag is a versatile solution for those looking for a stylish and expandable gym sling bag. The Knack Sling Bag is designed with the gym-goer in mind, offering the perfect combination of style, functionality, and versatility. With its spacious front compartment and separate, patent-pending expandable back compartment, our sling bag provides ample space for all your essentials.

This sling bag is made from a custom-developed, durable, and water-resistant 420D nylon body fabric that is lightweight and cool, making it perfect for any weather conditions. The spacer-mesh back panel provides added comfort, and the YKK™ water-resistant zipper with custom-designed pullers ensures that your belongings stay dry.

With a sleek 6 liters of storage space, this expandable sling bag expands to 10 liters with a simple zip. The expandable compartment provides an additional 4 liters of space, making it perfect for unexpected turns in your day, and provides enough space to keep your gym gear separate from your everyday items. 

Organization is a key feature of the Knack Sling Bag. The bag is designed with multiple compartments and pockets, making it easy to keep your items organized and within reach. You can easily access your essentials without having to rummage through the bag.

The best sling bags are built for everyday use, and the Knack Sling Bag is no exception. The bag is not only great for carrying your gym gear but it can also be used as an everyday carry bag. Whether you're heading to the office, running errands, or simply going for a walk, the Knack Sling Bag is the ideal companion.

Want to know more? Check out why these Knackpackers are raving about the Knack Sling Bag. 

We’d love to hear your take on what to look for in a great gym bag or if you think we missed anything. You can reach out to us at Also, please tag @knackbags and use #knackbags on social media when you take your Knack on your journeys!

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