A rashguard is not optional kit in BJJ — it's essential. Whether you're training no-gi, wearing one under your gi, or both, the right rashguard protects your skin, manages sweat, and prevents the kind of abrasions and infections that come from bare skin on the mat. The market is saturated with options ranging from £15 to £80+, and the difference in quality matters more than in many other pieces of gear. This guide will tell you what to look for, what the different styles are for, and how to choose without wasting money on something that pills, shrinks, or falls apart in three months. Whether you're just getting started with our classes or you've been training for years, there's something here for every level. A good rashguard is a long-term investment — get it right and you'll wear it for years.
What Rashguards Are Actually For
It's worth being clear on function before talking about products. Rashguards serve several distinct purposes in BJJ:
Skin Protection
Mat burn — the shallow abrasions you get from skin sliding across canvas or tatami — is a constant risk in grappling. A rashguard eliminates this on the torso and arms entirely. Beyond abrasions, skin-to-skin contact in a sweaty training environment is a vector for bacterial and fungal infections. A rashguard creates a barrier. This matters both for your own hygiene and as a courtesy to your training partners. The NHS guidance on preventing skin infections is worth a read — the principles apply directly to grappling environments.
Moisture Management
A quality rashguard wicks sweat away from the skin. This keeps you cooler during training and reduces the discomfort of sweat pooling under a gi jacket. In no-gi training it also means you're not leaving sweat on training partners unnecessarily.
Compression
Most rashguards offer some degree of compression, which some practitioners find reduces muscle soreness during and after training. The evidence for compression benefits in sports recovery is mixed — see Healthline's overview of compression gear for a balanced summary — but many people report subjective benefits and there's no downside to wearing it.
Warmth
In a cold gym, a long-sleeve rashguard under your gi adds meaningful warmth without bulk. Worth considering for training in autumn and winter, particularly in UK gyms that aren't always well-heated.
Styles and When to Use Each
Short Sleeve
The most popular style for no-gi training. Offers torso and shoulder protection with full arm mobility. Easier to put on and take off. Cooler in warm training environments. If you're buying your first rashguard and primarily training no-gi or in warm conditions, start here.
Long Sleeve
Full arm coverage. Preferred for under-gi use because the sleeves prevent skin bunching inside the jacket sleeves. Also provides maximum skin protection in no-gi. The trade-off is heat — some people find long sleeves uncomfortable in a warm gym during intense sparring. Better for winter training, for people with sensitive skin, and for those who prefer coverage.
Sleeveless / Tank
Less common but available. Offers torso protection only. Some practitioners wear these for warm training or when they want maximum arm mobility. Less practical for under-gi use.
Spats (Leggings)
Not a rashguard per se, but worth mentioning here because they serve the same function for the lower body. Essential for no-gi training to protect the knees and thighs from mat burn. Often worn under gi trousers too. If you're training no-gi regularly, spats pair with a rashguard as a complete outfit.
What to Look For in Quality
Fabric Blend
The gold standard in BJJ rashguards is a polyester/spandex blend — typically around 85% polyester and 15% spandex (elastane). This combination provides stretch, durability, and moisture-wicking properties. Avoid 100% polyester — it's less stretchy and less comfortable. Avoid blends that include cotton — cotton absorbs moisture and becomes heavy and uncomfortable during training.
Flatlock Stitching
This is the detail that separates a genuine sports rashguard from a generic compression shirt. Flatlock stitching lies flat against the skin, creating no raised seams that could irritate or cause abrasions during extended rolling. Check the seams on any rashguard before buying — or check the product description carefully when buying online. Rolled seams or overlocked stitching are signs of a cheaper product.
Sublimated Printing
Quality rashguards use sublimated dye printing, where the design is bonded into the fabric rather than printed on top. Sublimated designs don't crack, peel, or fade. Screen-printed or heat-transfer designs will deteriorate with washing and wear. Sublimated printing is now standard across most mid-range and premium brands.
Fit and Length
A rashguard should fit like a second skin — snug without restricting movement. Too loose and it bunches under the gi or catches on training partners. Too tight and it restricts shoulder mobility. Pay attention to length: the hem should stay tucked when you're moving, stretching, and being taken down. Some brands offer "competition cut" models with extra length to satisfy IBJJF requirements.
Price Brackets and What to Expect
Under £20 — Avoid for Regular Training
Generic compression shirts from general sportswear retailers sometimes double as BJJ rashguards, but they're not designed for grappling. The stitching fails under repeated grabbing and rolling, the fabric thins quickly, and they rarely have the flatlock seams needed for comfort. Save your money for something purpose-built.
£20–£40 — Entry-Level BJJ Specific
Brands like Sanabul, Elite Sports, and Venum's entry range all offer purpose-built BJJ rashguards in this price bracket. Quality is adequate for training — you'll get flatlock stitching and a proper fabric blend. Durability is moderate; expect to replace after 12–18 months of regular training.
£40–£70 — Mid-Range: Best Value
This is the sweet spot. Tatami Fightwear, Scramble, and Hypnotik all offer excellent rashguards at this price point. Better fabric quality, more durable construction, and design options that hold up over years of washing. For most people who are training regularly, this is the bracket to aim for. For no-gi cross-referencing, see our separate guide on when to wear a rashguard versus a gi.
£70+ — Premium
Premium rashguards from Shoyoroll, Kingz, or boutique BJJ brands can run to £80–£120. The quality is excellent but the performance difference over a good mid-range option is marginal. Premium products often have distinctive aesthetics and collector appeal. Worth it if that matters to you; not necessary for functional training.
Rashguard Fit by Body Type
Rashguards follow a compression fit that sits closer to the body than standard athletic wear. For this reason, getting the sizing right matters more than with looser garments. Most brands size rashguards by chest measurement and height. If you're between sizes, consider your primary use case:
- Under the gi: Err on the slimmer/standard fit. Too much excess fabric under the gi jacket creates bunching that becomes uncomfortable during training.
- No-gi training: A standard fit works. Some practitioners prefer a slightly looser "athletic fit" rashguard for no-gi training — it looks better and feels less like a second skin, with minimal performance difference.
Some brands offer women-specific cuts with adjusted waist-to-hip ratios and bust accommodation. Female practitioners often find that fitted women's rashguards are significantly more comfortable than standard unisex cuts, particularly around the shoulders and torso. Worth checking brand-specific options if standard sizing isn't working well for you.
No-Gi vs. Under-Gi: Different Requirements
A rashguard used primarily under the gi has different practical requirements to one used for no-gi training:
Under the Gi
Long sleeve is preferred. The sleeve prevents skin bunching inside the gi jacket sleeve — a minor but persistent irritation with short-sleeve rashguards in gi training. The collar area of a rashguard should not add significant bulk at the neck, as the gi collar will press down on it. Avoid rashguards with thick neck collars or high necks for under-gi use. Colour doesn't matter under the gi, so this is a good place to use a rashguard you like the feel of but wouldn't choose to show off in no-gi.
No-Gi Training and Competition
For no-gi competition, check the specific rules of your organisation. The IBJJF no-gi competition requirements specify rashguard colours and sleeve lengths at higher belt levels. For most recreational training and lower-level competition, any quality rashguard in black, white, or belt-matching colour is acceptable. Short sleeve works fine for no-gi training in most environments.
Care and Longevity
A rashguard will last significantly longer if you care for it properly. Rinse it immediately after training — salt from sweat degrades elastane over time. Wash in cold water on a gentle cycle. Never tumble dry — heat destroys the elastane and causes shrinkage. Air dry away from direct sunlight. Avoid fabric softener, which coats the fibres and reduces moisture-wicking performance. Following these steps can extend the life of a rashguard from one year to three or more.
Rashguard Hygiene on the Mat
A rashguard must be clean for every training session — the same hygiene standards as your gi. Sweat and bacteria accumulate in the fabric during training, and a rashguard worn in a second session without washing creates a hygiene risk to both you and your training partners. The Healthline guide on gym hygiene notes that reusing workout clothes without washing significantly increases bacterial load on the skin. In a grappling environment where skin contact is constant, this matters more than in most sports.
Rinse your rashguard with cold water immediately after training if you can't wash it immediately. This removes the bulk of sweat and slows bacterial growth. Then wash it in cold water as soon as possible — don't let it sit in your bag overnight. Following this routine, a good quality rashguard should remain odour-free for years.
Conclusion
You don't need an expensive rashguard to start training, but you do need one that's built for the job. Aim for a purpose-built BJJ rashguard with flatlock stitching and a polyester/spandex blend in the £20–£40 range to start. Once you know your training frequency and preferences, invest in something from the mid-range bracket that will serve you for years. Long sleeve for under the gi, short sleeve for no-gi in warmer conditions — and spats to pair with it for full coverage. If you're just getting started, don't overthink it. Come to your free trial in any close-fitting sports top and we'll get you sorted from there.
Come Train With Us
Don't worry about having the perfect gear yet. Your first class at Samurai Fitness BJJ is free — just show up.
Book Your Free Trial