Body protectors are foam filled vests designed to reduce the risk of injury to the upper body of the rider. Testing procedures suggest that the force of impact transmitted to the body will be reduced from falls on flat surfaces as well as there being some protection against sharper or angular objects including horse hoofs! Shoulder pads are a sensible optional addition to provide greater protection. The shoulder is a relatively common point of impact when riders fall.
BETA has produced a guide summarizing the standards involved in different levels of protection. BETA has also published a statement in 2012 on recent changes to the rules on body protector standards accepted in British Eventing and also Air Vests (Body Protectors for the Season Ahead).
Body protectors must be worn by all jockeys racing under BHA rules and all competitors riding cross country courses under BE rules. Similar rules are normally adopted by unaffiliated competitions such as Hunter Trials. Many riders wear them at other times such as when riding on the road and schooling young horses.
There is no guidance about whether body protectors should be worn out of competition.
Current body protectors are more comfortable and tend to mould to the rider more than earlier types. They can still feel hot and bulky. Many riders feel that their position and balance are compromised even by the best-fitting body protectors. This is why they are not always worn away from cross country or racing courses. It's important to choose the body protector that suits you best. There are variations in style of manufacture which includes the foam protection being arranged in larger sheets or panels, small blocks or more recently hexagons! Most have front zips although there are foam panel types without zips. Weight, comfort, freedom of movement and length at the back are all important. Your body protector should be fitted by a trained retailer whilst you sit on a saddle. Does it push your arms out? Does the back catch on the saddle too much?