action
challenge
compete
competition
course
difficult
dirt
dirty
diving
dust
endurance
energy
event
exercise
extreme
fast
feet
fit
fitness
grit
individual
jumping
legs
mental
mud
muddy
obstacle
outdoors
painful
participant
participating
people
physical
race
run
runner
running
shock
skill
sport
sporting
strength
strong
team
test
tough
toughest
water
wet