Quality footwear is vital. If you don't want your
feet to slip out from under you could opt for something
with knobblies such as football boots, cross-country
trainers, or mountain/walking boots. If you prefer
your feet to slide out, wear ordinary boots or trainers.
Basically the more traction you have the more likely
you are to get a twist or jarring injury to your ankles,
knees, legs... The less traction you have, the more
likely it is that you'll have your feet slip out from
under you which could cause a number of injuries,
ranging from broken or sprained wrists, arms, and
other injuries associated with sliding and tumbling
down a big hill.
Clothing: protective armour would be good but traditionally
its not in the spirit of the event. Most runners wear
clothing that is tough and can withstand some abuse
like jeans and a rugby shirt. If the conditions are
dry the ground will be damn hard and you are more
likely to acquire bruises and abrasions.
If you participate in this event you should expect
to be injured!