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Are Rashguards Supposed to Be Tight for BJJ?

In the world of Brazilian Jiu Jitsu (BJJ), the rash guard is a staple piece of attire for both training and competition. It’s designed to provide compression, be moisture-wicking, and not get in the way of training…


For Brazilian jiu jitsu, your rashguard should fit snug to your body around your chest, shoulders, and arms with a little more space in your midsection. It should be tight enough to not get int the way of training but not too tight where it limits your movement, breathing, or bloodflow.


Key Takeaways

  • Your rashguard fit will obviously come down to your personal preference
    • for me, I like my rashguard to be somewhat tight around my upper body and slightly looser around my stomach (if it’s too tight I feel like it just makes it harder to breath)
  • Rash guards should fit snugly, offering protection without restricting movement.
  • If you are heavier, don’t worry about the rashguard showing your stomach, we are all at jiu jitsu to train and have fun I promise no one is thinking about how you look in a rashguard.
  • If you end up wearing a longer or loose rashguard you can always tuck it in too

How to Tell if Your Rashguard Is Too Tight

Your rashguard is too tight if:

  • you struggle for more than a couple seconds getting it on or off
  • you find it difficult to get a full inhale in
  • it’s difficult to raise your arms over your head
  • you are sweating quite a bit during warmups
  • seams and stiching show early signs of wear and tear

On the other hand, the worst thing you can do is have your rashguard be baggy or too big. It will force you to constantly adjust it during training and won’t be fun for you or your training parnter.


Rash Guards Basics

Function of Rash Guards in BJJ

Rash guards serve multiple purposes in BJJ.

  • Primarily, they protect the skin from abrasions, or “mat burns,” which can occur during close contact and grappling maneuvers.
  • They also act as a barrier to prevent skin infections by reducing direct skin-to-mat contact.
  • Finally, by wicking away moisture, rash guards help maintain body temperature and reduce friction, thereby minimizing the risk of rashes.

During No-Gi BJJ, rash guards are highly recommended as they help movement and provide a level of compression that can aid muscle recovery.

Material and Fabric of Rash Guards

Fuji Rashguard: 100% polyester (thinner, durable, very breathable)
Xmartial: 80% polyester and 20% spandex (a little thicker material)

The fabric of a rash guard is designed for durability, flexibility, and comfort.

Common materials in rashguards include a blend of polyester and spandex, or nylon and spandex.

These materials are chosen for their elasticity and moisture-wicking properties, which are essential for the intense physical activity in BJJ.

  • Polyester-spandex blend: Offers a balance between durability and stretchability.
  • Nylon-spandex blend: Generally provides a softer texture with similar stretch capabilities.

Using materials that combine elasticity with compression allows the rash guard to fit tightly against the body without restricting movement or blood flow. The tight fit is essential to prevent the fabric from catching or bunching up, which could hinder performance or increase the risk of injury.

Fit and Sizing of Rash Guards

How to Determine the Right Size

To ensure an accurate fit, individuals should refer to brand-specific size charts, which take into account one’s height and weight. Measurement of the chest, waist, and arms is recommended for a more precise fit.

Again, a properly sized rash guard should feel snug without restricting movement.

Benefits of a Tight Fit

A tight fit offers multiple advantages:

  • Reduced risk of infections: A closer fit means less material for pathogens to latch onto.
  • Minimized friction: Snug rash guards can lessen the likelihood of mat burns.
  • Muscle support: Compression can aid in muscle stabilization and recovery.

Potential Issues With Too Tight or Loose Fits

  • Too Tight: Restricts movement, potentially causing discomfort and hindering performance.
  • Too Loose: Increased risk of the fabric catching or shifting during training, which can distract the practitioner and impact grappling effectiveness.

Performance and Protection

Enhancement of Athletic Performance

In BJJ, a rash guard should tightly conform to the practitioner’s body, akin to a second skin. This snug fit allows for a full range of motion and is intended to produce a compression effect. Compression can lead to:

  • Improved muscle oxygenation
  • Enhanced proprioception, which gives a better sense of one’s body in space

These factors play a critical role in executing precise movements and maintaining stamina, especially in the demanding conditions of grappling sports.

Protection Against Mat Burns and Friction

Rash guards serve as a protective barrier for practitioners by reducing direct contact with the mats and opposing participants. This shielding function helps to prevent:

  • Skin abrasions commonly known as mat burns
  • Irritation due to friction

Moreover, rash guards support maintaining better hygiene by limiting exposure to potential skin infections. Their moisture-wicking properties aid in keeping the skin dry and less susceptible to pathogens.

Maintenance and Longevity

Proper Washing and Care

To maximize the longevity of a BJJ rash guard, it’s imperative to clean it effectively after each training session.

The safest way to wash your rashguard is by throwing it in the washing machine on a gentle cycle with cold water with strong detergents when you get in from jiu jitsu training then let it hang dry.

However, most rashguards are now able to be put into the dryer (a low tumble cycle is recommended). I personally prefer to put mine in the dryer since I feel like they get cleaner that way.

Choosing the Right Rash Guard

Some factors to consider when buying a rashguard are:

  1. Gym Requirements: does your gym require you to wear their rashguard or a specific brand or color (based on your belt rank)
  2. Fit: how well does it fit?
  3. Design: do you like the design of it?
  4. Comfort: is it comfortable to train in day in and day out?
  5. Brand Reputation: is it from a trusted brand with easy to contact support and a clear return policy?
  6. Price: how affordable or how expensive is it?
  7. Material: what is it made of? Do you want a thinner breathable rashguard (with more polyester*) or a thicker one?
  8. Durability: if its more affordable will it last more than a month or two?
  9. Sleeve Length: do you prefer short or long sleeves? Do you train in a hot climate? Are you prone to sweating a lot and getting hot very easily (like me*)?
  10. Ranked/IBJJF Legal: are you planning on competing in an IBJJF event? Is it ranked and legal for the IBJJF?

Frequently Asked Questions

When selecting a BJJ rash guard, understanding the nuances of fit can enhance both performance and comfort. This section addresses common inquiries to assist in making an informed choice.

What is the recommended fit for a BJJ rash guard?

A BJJ rash guard should fit snugly against the body without impeding circulation or movement. It should allow for roughly an inch of stretch across the torso.

Do you tuck in a rashguard for BJJ?

While you can tuck in a rashguard into your shorts, spats, or gi pants it’s not required. Tucking in your rashguard can be done if your rashguard is longer or looser and you want to avoid it getting in the way of training. It can also be a style preference too.

How much do rash guards typically stretch after use?

Rash guards are designed with materials that offer a small degree of elasticity and are meant to retain their shape. They may stretch slightly but should not become loose with proper care.

Is there a difference between men’s and women’s BJJ rash guard fits?

Yes, women’s BJJ rash guards are typically designed with a snug fit specific to their body structure. They should allow for a stretch of about one inch for optimal performance and protection.

Should a rash guard be tucked in during BJJ training or competition?

It’s a matter of personal preference, but a rash guard that stays in place, potentially with a gel panel to prevent it from riding up, can be advantageous during rolling and grappling.

What are the benefits of wearing a tight versus a loose rash guard for BJJ?

A tight rash guard minimizes the risk of skin infections and mat burns while ensuring the garment does not impede movement. A loose rash guard may bunch up and can lead to increased friction and potential for catching fingers and toes.

Where can I find a size chart to ensure a proper fit for my BJJ rash guard?

Most manufacturers provide a size chart on their websites or product packaging. As always, it is important to refer to these charts as sizes can vary between brands.

    About the Author:

    Zack Nicholas

    Zack Nicholas:

    Zack is an avid jiu jitsu practitioner and weight lifting nerd. When not on the mats or in the gym, he can be found going for walks with his wife, attempting (and often failing) to train his dog, and frequently obsessing over a specific hobby only to forget about it a week later. He can be reached over his LinkedIn or at info@heavybjj.com