Common gear used during Adventure racing (as used during Action Asia Challenge 2008):

• climbing harness - UIAA approved and not older than 6 years
• 3 x locking Carabiners (1 x screw gate for abseil and 2 x screw gate or auto-locking for fixed lines)
• helmet, either bike or climbing
• 2 x 50-60cm slings, commercially sewn, not tied (length measured when laid out flat). Cord, prussic loops, shorter or longer slings will not be allowed unless specific event makes an anouncement.
• figure 8 descending device (size medium)
• mountain bike (Tires min 1.75 inch wide and wheels 26 inch diameter)
• pair of gloves (full finger for abseil section unless specific event allows fingerless in announcement like Macau)
• Running/trail/cross training or cross country shoes
• 2 Liter minimum hydration fluid system
• Food - Energy bars/gels (recommended 250 calories per hour of activity) with water proof packaging
• Headlamp & bike lamp with spare batteries
• first-aid kit (a recommended list of contents is published on the event's web site)
• compass with pen/pencil
• bicycle pump
• spare tubes (if using tubed tyres)
• tool kit
• patch kit
• Whistle

Recommended Nutrition:

• Gels (GU, Power Bar, Accel Gel, High5, Clif Shot)
• Sharkies / Clif Block Shots
• Power Bars / Cereal bars
  
• Dried Mango
• Boiled potatoes
  
• Salt tablets
• Nuun Electrolyte tablets
• R4 / Accelerade / CarboPro1200 / Infinit drink mixes
• Salty snacks for longer races
• Whatever works for you...