What do jiu-jitsu athletes wear, and how long is a match?

• Gi: clean white woven cotton, fitting well, with a red or a blue belt.
• Women in the gi: a mostly white or mostly black rash guard under the jacket.
• No-gi: a skin-tight rash guard that is mostly red or mostly blue, with sleeves, and athletic shorts to between mid-thigh and the knee.
• Underwear: elasticated undergarments are compulsory. Wearing unsuitable ones is a disqualifying foul.
• Not allowed: jewellery, piercings, watches, headgear, glasses and anything hard.
• Allowed: soft supports, tape on the skin and an elastic hijab in women's divisions.
• Match times: five minutes for adults, under 21 and masters, four for under 18, three for under 16 down to under 12, and one and a half for under 10 and younger.
• Rest: at least five minutes between matches, and ten before a medal match.
• The mat: a fighting area of at least 8 m by 8 m, with a 1 m safety area, 10 m by 10 m in all.
• Weight categories: seven for adult men, from under 56 kg to over 94 kg, and seven for adult women, from under 45 kg to over 70 kg.

The glossary has the gi and no gi, the match area, the match times (ne-waza), the weight divisions, the uniform inspection and the age categories.

The gi gives handles: collars, sleeves and trouser legs that make a slower, grip-based game. No-gi takes them away and makes a faster one. The rule that no-gi kit must be tight, with no pockets or zips, keeps the clothing from becoming a grip or an injury.