What to Wear Under a BJJ Gi: A Comprehensive Guide
Introduction
Brazilian Jiu-Jitsu (BJJ) is a physically demanding martial art that requires proper attire for comfort, hygiene, and performance. While the BJJ gi is the primary uniform, what you wear underneath it plays a crucial role in your training experience. This guide explores the best options for undergarments, their features, application scenarios, and maintenance tips.
1. Rash Guards
Key Features:
Material: Typically made from polyester-spandex blends (80/20 or 70/30 ratios) for moisture-wicking and stretch.
Compression: Provides 8-15 mmHg of pressure to improve blood circulation and reduce muscle fatigue.
UPF Protection: Offers UPF 50+ sun protection for outdoor training.
Antimicrobial: Treated with silver-ion or polygiene to prevent bacterial growth.
Application Scenarios:
Ideal for no-gi training under the gi for added sweat absorption.
Recommended for competitions to prevent skin infections.
Useful in hot climates to regulate body temperature.
Maintenance:
Wash in cold water (30°C/86°F max) to preserve elasticity.
Avoid fabric softeners as they clog moisture-wicking pores.
Hang dry to prevent shrinkage.
2. Compression Shorts
Key Features:
Material: Nylon-spandex (90/10 blend) for durability and flexibility.
Seamless Design: Reduces chafing with flatlock stitching.
Moisture Management: Wicks away 95% of sweat within 10 minutes.
Groin Support: Features 3D molded cups or reinforced panels for protection.
Application Scenarios:
Essential for guard players to prevent mat burns.
Used in long training sessions (2+ hours) to minimize friction.
Critical for women practitioners for added modesty.
Maintenance:
Turn inside out before washing to preserve the inner lining.
Use mild detergent (pH 6-7) to maintain antimicrobial properties.
Never iron or dry clean.
3. Sports Bras (For Female Practitioners)
Key Features:
Support Level: High-impact (ENC 3-4 rating) with encapsulation design.
Straps: Cross-back or racerback with 5-10mm width for stability.
Breathability: Laser-cut perforations (2-3mm diameter) for ventilation.
Closure: Hook-and-eye (3-4 rows) or pullover designs.
Application Scenarios:
Mandatory for rolling sessions to prevent discomfort.
Preferred in competitions where gi friction is intense.
Recommended for bust sizes 32D and above for optimal support.
Maintenance:
Hand wash in lukewarm water (40°C/104°F max).
Air dry flat to maintain shape.
Replace every 6-12 months as elasticity degrades.
4. Base Layer T-Shirts
Key Features:
Weight: 120-150 GSM for optimal balance between warmth and breathability.
Neckline: Crew neck or mock neck to prevent gi collar abrasion.
Odor Control: Polygiene or merino wool (17.5 micron) blends.
Fit: Semi-fitted (5-7% negative ease) to avoid gi bunching.
Application Scenarios:
Suitable for cold weather training (below 15°C/59°F).
Used when recovering from skin infections as a protective barrier.
Ideal for beginners adjusting to gi fabric friction.
Maintenance:
Wash with similar colors to prevent dye transfer.
Use mesh laundry bags to protect seams.
Tumble dry on low heat (max 60°C/140°F) if needed.
5. Leggings (For No-Gi Under Gi)
Key Features:
Gusset: Diamond-shaped crotch panel (4-way stretch) for mobility.
Grip: Silicone prints (0.5mm thickness) at the waistband to prevent slipping.
Knee Padding: EVA foam inserts (3-5mm) for shooting takedowns.
Ankle Cuffs: Elastic binding (1.5-2cm width) to stay in place.
Application Scenarios:
Worn during transitional weather when alternating gi/no-gi rounds.
Recommended for practitioners with sensitive skin or eczema.
Used in IBJJF rulesets where pants must cover knees.
Maintenance:
Soak in vinegar solution (1:4 ratio) monthly to remove odor buildup.
Store folded to prevent elastic deformation.
Avoid bleach which degrades spandex fibers.
Conclusion
Selecting the right undergarments for BJJ requires understanding material technologies, biomechanical needs, and hygiene protocols. By matching these options to your training conditions and maintaining them properly, you'll enhance both performance and longevity of your gear.
