What To Wear Under A BJJ Gi

If you are new to Brazilian Jiu Jitsu, one of the first questions you may ask is: what should I wear under my gi?

The answer depends on whether you are training, competing or buying kit for a child, but comfort and hygiene should always come first.

For Everyday BJJ Training

Most practitioners wear a rashguard under their gi jacket. A rashguard helps reduce friction, absorbs sweat and creates a more comfortable layer between your skin and the gi.

Under gi trousers, you can wear compression shorts or suitable athletic underwear. Avoid anything with zips, buttons or hard seams, as these can be uncomfortable during grappling.

For Kids BJJ

For children, comfort is especially important. A lightweight rashguard under the gi can help them feel more secure and reduce irritation during class.

Make sure the gi is not too tight and not too long. A poor fit can make training harder, especially for younger children.

For Competition

Competition rules can vary depending on the organiser, so always check the event requirements before the day. Some competitions may have specific rules around rashguards, colours or visible clothing under the gi.

Best Practice

For most training sessions, the ideal setup is:

  • BJJ Gi
  • Rashguard
  • Compression shorts or suitable base layer
  • Belt
  • Flip-flops or sliders for walking off the mat

Wearing the right layers keeps training more comfortable, hygienic and practical.

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