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Why the KNKG Core Duffel is the Best Gym Bag We Have Ever Used

When it comes to training, the KNKG Core Duffel is our top pick for strength, weightlifting and functional fitness athletes.

When it comes to training, the KNKG Core Duffel is our top pick for strength, weightlifting and functional fitness athletes. It has everything that every serious gymgoer needs to bring their A game each time they step inside the gym, box or weightlifting platform.

Your gym bag should be a point of pride, not a tired, dirty and odorous blob that simply carts everything around in a formless mass.

Your gym bag is the foundation and organisational support to help you through every workout. It reflects your goals, training structures and dedication to the workout at hand. Like a good warm up, it sets the tone for the time ahead.

Founded in 2011, the original idea behind KNKG (short for King Kong) was to craft the best quality and most functional gym bags that existed.

We think they succeeded.

What Factors Should You Consider When Buying a Gym Bag?

When buying a gym bag, there are several factors you should consider to ensure that it meets your specific needs and preferences.

Here are some important factors to consider:

Size and Capacity

Consider the size of the bag based on the items you plan to carry to the gym. Think about your workout routine and the types of equipment or clothing you’ll need to bring along.

A gym bag should have enough space to accommodate your essentials without being overly bulky.

Compartments and Organization

Look for a bag with multiple compartments and pockets to help you keep your belongings organised. Separate compartments for shoes, wet items, and valuables can be particularly useful.

group class vs pt crossfitSource: Stevie D Photography

This makes it easier to find what you need quickly and prevents items from getting mixed up or damaged.

Durability and Material

Choose a gym bag made of durable materials that can withstand frequent use and carry heavy items.

Nylon, polyester, or canvas are common materials used in gym bags, known for their durability and water resistance. Reinforced stitching and sturdy zippers are also important for long-lasting performance.

Comfort and Carrying Options

Consider the bag’s carrying options. Look for padded handles and adjustable shoulder straps for comfortable carrying.

Some bags may also have additional features like a cross-body strap or backpack-style straps, allowing you to choose the most comfortable carrying method for your needs.

Ventilation and Odor Control

If you plan to carry sweaty gym clothes or shoes, opt for a bag with ventilation features such as mesh panels or ventilated shoe compartments. This helps prevent odours from building up and allows for airflow to keep your items fresh.


Look for a gym bag that offers some level of security for your belongings. Features like lockable zippers or hidden pockets can provide added peace of mind, especially if you need to leave your bag unattended in a locker room or other shared space.

Design and Style

While not essential, the design and style of the bag may be important to you. Choose a bag that reflects your personal taste and suits your lifestyle. Consider colour, patterns, and any additional aesthetic elements that are important to you.


Set a budget for your gym bag and consider the value for money. There is a wide range of options available at different price points, so it’s essential to find a balance between quality and affordability.

By considering these factors, you can find a gym bag that meets your requirements in terms of size, durability, organization, comfort, and style, ensuring a more enjoyable and hassle-free gym experience.

KNKG Core Duffel Gym Bag

This gym bag has everything that you need, as has also been featured in Wirecuter, Men’s Health, Gear Patrol and Business Insider.

Available in black, desert and green it features a unique weightlifting belt attachment to keep your kit secure and safe.


The KNKG Core Duffel is superbly designed to withstand all the rigours of training for many years to come.  You never need to worry about rips or tears.

The design choices utilise carefully selected and extremely durable materials. Combined with the expert craftsmanship, you are given a bag that excels in both form and function.

The CORE Duffel is made from:

  • 500D nylon body material (PVC backing)
  • Powder-coated steel buckles
  • Ripstop nylon lining
  • Nylon webbing
  • YKK zippers

It also features a 13/15” Internal laptop sleeve (perfect if you train after work), a sealed internal shoe compartment and dual bottle pockets (one for water, one for that post workout protein shake.


The medium variation has a carrying capacity of 35l, whilst the large model can fit in 51l worth of gear.


  • Man of Many #1 gym bag 2022
  • Generation Iron Rated ‘Best Powerlifting Gym Bag’
  • Powerlifting Technique’s Top Pick Best Gym Bag



The KNKG Core Duffel is covered by their promise to be free of defects in material or workmanship within its practical lifetime.

If there is a defect in materials or workmanship then King Kong will happily repair or replace your bag, even providing free shipping.

Why are Good Quality Materials Essential When Buying a Gym Bag?

Good quality materials are essential when buying a gym bag for several reasons:

Durability: A gym bag undergoes regular use, and it needs to withstand the wear and tear of carrying heavy items, being tossed around, and enduring various environments.

High-quality materials such as nylon, polyester, or canvas are known for their durability and ability to withstand frequent use without easily tearing or breaking.

Longevity: Investing in a gym bag made of good quality materials ensures that it will last longer.

Cheaper bags made of subpar materials may show signs of wear and tear after only a short period of use, potentially leading to the need for a replacement.

By choosing a bag made of high-quality materials, you can enjoy its benefits for an extended period.

Protection: Your gym bag is responsible for keeping your belongings safe and protected. Quality materials offer better protection against external factors such as moisture, dirt, and impacts.

For example, water-resistant or waterproof materials can safeguard your items from rain or accidental spills.

Additionally, sturdy materials provide better cushioning and shock absorption, protecting fragile items like electronics or glass containers.

Ease of Cleaning: A gym bag is exposed to sweat, dirt, and odours from your workout gear. Good quality materials are often easier to clean, making it simpler to maintain the bag’s cleanliness and hygiene.

Some materials are machine washable or can be easily wiped clean, helping to keep your gym bag fresh and odour-free.

Appearance: A gym bag made of high-quality materials tends to have a more attractive and polished appearance. It retains its shape, colour, and overall aesthetic appeal over time.

This can be important if you use your gym bag for other purposes, such as traveling or as an everyday bag, where you want to maintain a professional or stylish look.

Overall, investing in a gym bag made of good quality materials ensures durability, longevity, protection for your belongings, ease of cleaning, and an appealing appearance.

While it may require a higher upfront cost, it is always worth it and will save you money in the long run by avoiding the need for frequent replacements.

KNKG Core Backpack

If you need something a little smaller, then we would recommend the KNKG Core Backpack.

This is a versatile and excellent backpack, perfect when you need to train, but might not require two pairs of shoes or such an extensive array of kit.

Don’t worry though, you can still comfortably fit your training shoes in the bottom of the bag.

It was voted the Man of Many #1 gym bag 2022, and closed out last year as the Men’s Journal top pick for the active man in 2022.

It is King Kong’s bestselling gym bag.

The main difference between this and the previous gym bag is the unique weightlifting belt attachment.

This feature allows the bag be used as a regular backpack, whilst carrying the lifting belt on the outside.

The backpack has two variations based on volume, at 25l and 33l respectively.


  • Unique weightlifting belt attachment
  • Colours: black desert and green
  • External weightlifting belt attachment
  • 15” Internal laptop sleeve
  • Sealed internal shoe compartment
  • Dual bottle pockets


The CORE Backpack is made from:

  • 500D nylon body material (PVC backing)
  • YKK zippers
  • Ripstop nylon lining
  • Nylon webbing


What are the Advantages of YKK zippers on Duffel Bags?

YKK zippers are widely recognized and preferred by many manufacturers and consumers for their high quality and reliability.

When it comes to duffel bags and backpacks, the use of YKK zippers offers several advantages:

Durability: YKK zippers are known for their exceptional durability. They are designed to withstand frequent use and the rigors of opening and closing a bag.

The materials and construction of YKK zippers make them less prone to breakage or getting stuck, ensuring that your duffel bag remains functional over an extended period.

Smooth Operation: YKK zippers are known for their smooth and effortless operation. The teeth of the zipper mesh together seamlessly, allowing for easy and reliable opening and closing of the bag.

This smooth operation enhances the overall user experience, preventing frustrations commonly associated with cheap or unreliable zippers.

Strength and Security: YKK zippers are known for their strength and resistance to pulling apart. They are less likely to separate or break under stress, providing an added level of security for your belongings.

This is particularly important for duffel bags or backpacks that may contain heavy items or when you need to secure your bag during travel.

Self-Repairing Feature: YKK zippers often come with a self-repairing feature. If a portion of the zipper gets misaligned or separated, you can simply move the slider back and forth to realign and repair it.

This feature is convenient and can save you from the hassle of replacing the entire zipper or seeking repair services.

Availability and Reputation: YKK is a well-established and reputable brand in the zipper industry. Their zippers are widely available, making it easier to find replacements or spare parts if needed.

The brand’s reputation for quality and reliability gives consumers confidence in the performance of their products.

Athlete mid dumbbell snatchSource: Stevie D Photography

By using YKK zippers on duffel bags and backpacks, King Kong ensures that their products have sturdy, reliable, and long-lasting closures.

This not only enhances the overall quality of the bag but also provides peace of mind to users, knowing that their belongings are secure and protected.

KNKG Gym Bags: Room for Everything

So, what exactly can you fit in your new bag?

Weightlifters typically have specific items they carry in their gym bags to support their training sessions.

Weightlifting Shoes

Weightlifting shoes provide stability, support, and an elevated heel to help weightlifters maintain proper form during lifts. These specialized shoes are designed to optimize performance and safety during weightlifting movements.

Lifting Straps

Lifting straps are used to improve grip and assist in holding onto heavy weights, particularly during exercises like deadlifts, rows, or shrugs. They wrap around the wrists and attach to the barbell, reducing the strain on the grip muscles.

Wrist Wraps

Wrist wraps provide additional support and stability to the wrists during heavy lifting. They are wrapped around the wrists to help prevent excessive bending or hyperextension, reducing the risk of injury.

Knee Sleeves or Wraps

Knee sleeves or wraps are worn to provide compression, warmth, and support to the knee joints. They can help with stability, reduce pain, and provide a sense of confidence during squats, lunges, or other lower-body exercises.

Weightlifting Belt

A weightlifting belt is used to provide core stability and support during heavy compound lifts such as squats and deadlifts. It helps maintain proper form and can increase intra-abdominal pressure, enhancing spinal support.


Chalk is commonly used by weightlifters to improve grip by reducing sweat and enhancing friction. It is particularly useful for exercises like deadlifts, pull-ups, and heavy barbell lifts.


A small towel is useful for wiping off sweat during intense training sessions. It helps keep hands and equipment dry, maintaining a secure grip.

Water Bottle

Staying hydrated during workouts is crucial, so weightlifters often carry a water bottle to ensure they have easy access to fluids. It’s important to replenish fluids lost through sweat to maintain performance and prevent dehydration.

Gym Clothes

This includes comfortable workout attire such as shorts, t-shirts, and athletic socks. Weightlifters prefer clothes that allow freedom of movement and moisture-wicking properties to keep them dry and comfortable.

Personal Care Items

Weightlifters may include personal care items like a small towel, shower essentials, deodorant, and post-workout recovery aids such as foam rollers or massage tools.

Gym Accessories

Other accessories like a workout log or training notebook, wrist wraps, grip pads, or compression garments may be part of a weightlifter’s gym bag depending on their preferences and specific training needs.

Remember, the specific items in a weightlifter’s gym bag can vary based on individual preferences, training goals, and the specific workout routine.

Why is a Great Gym Bag Essential for All Weightlifters and Fitness Lovers?

A great gym bag is essential for all weightlifters and fitness lovers for several reasons:

Organization and Convenience: A well-designed gym bag helps keep all your workout essentials organized and easily accessible.

It typically offers multiple compartments and pockets to store items like shoes, clothing, accessories, water bottles, and personal care products. This ensures that you can quickly find what you need, saving time and eliminating the hassle of rummaging through a disorganized bag.

Protection of Equipment and Belongings: A dedicated gym bag provides a safe and protective space for your weightlifting equipment and personal belongings.

It helps prevent damage or loss by keeping items separate from other gym equipment, minimizing the risk of scratches, spills, or accidents.

Features like padded compartments and reinforced stitching offer additional protection for fragile items such as electronics or valuables.

Hygiene and Cleanliness: Carrying a gym bag allows you to separate your used workout gear from the rest of your belongings, preventing the spread of sweat, dirt, or odours.

Many gym bags include features like ventilated compartments or designated spaces for wet or dirty items, helping to keep your bag and other items fresh and odour-free.

Convenience for Travel and Commuting: A gym bag is not only useful for workouts but also for traveling to and from the gym.

It provides a convenient and organized way to carry your workout gear, clothes, and accessories.

Whether you’re commuting to a nearby gym or traveling to a different location, a well-designed gym bag makes it easier to transport all your fitness essentials.

Versatility and Multi-functionality: A great gym bag can serve multiple purposes beyond the gym. It can be used as a travel bag, weekend bag, or even a daily work bag, depending on its design and size.

This versatility allows you to make the most of your investment and eliminates the need for multiple bags for different purposes.

Motivation and Mindset: Having a dedicated gym bag that you love and feel proud to carry can enhance your motivation and mindset towards fitness.

It creates a sense of commitment and readiness, reminding you of your goals and the importance of staying consistent with your workouts. A great gym bag can become a symbol of your dedication to a healthy and active lifestyle.

By investing in a great gym bag, weightlifters and fitness lovers can enjoy the benefits of organization, protection, convenience, hygiene, versatility, and an enhanced mindset. It becomes a reliable companion that supports their fitness journey and makes their overall gym experience more enjoyable and efficient.

Why Choose KING KONG?

Designed by athletes for athletes, King Kong strive for the best quality design, materials, style and production possible.

“Our goal is to make bags that not only address everyday carry needs, but also enhance the way we train, explore, and push ourselves to the limit. We believe in packing for greatness with gear that is as tough as you are, and can withstand even your toughest workouts.”

“Each King Kong bag is made with the most durable materials and construction techniques to ensure it can stand the test of time. Every element, from compartments and zippers to pockets and buckles, is tested for durability and efficiency, so you can trust that you are prepared to handle any challenge.”

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