The stable provides horses with a protected environment but it restricts the opportunity for exercise. This study aimed to examine post-inhibitory increase in locomotor behaviour (termed rebound) in horses following four exercise regimes and to determine if regular exercise reduced the occurrence of unwanted behaviour compared to un-exercised control treatments. Twenty-four stabled horses were assigned to one of four exercise regimes - walker, treadmill, turn-out and riding - for one hour per day for four consecutive days. Each horse served as its own control in four corresponding (un-exercised) control treatments. Unwanted behaviour was tested by routine handling by an experienced handler, and rebound behaviour was tested by releasing them into a large (80 x 80 m) arena for a period of 15 minutes. Locomotor activities made up a large part of behaviour in the large arena but all exercise regimes were sufficient to reduce the amount of walking (1123±123 to 672±91 steps, P<0.05), trotting (179±24 to 66±10 steps, P<0.01) and cantering (231±16 to 65±13 steps, P<0.001) compared to control treatments. Turn-out reduced bucking (6.2±0.5 to 2.0±0.4 bouts, P<0.01) and rolling (1.6±0.1 to 1.0±0.2 bouts, P<0.05) during rebound tests compared to un-exercised controls. Exercise regimes reduced unwanted behaviour (1.1±0.2 to 0.2±0.5 events) and the number of commands (0.9±0.3 to 0.4±0.2 commands) given by the handler during weighing (both P<0.05) but had no effect on these behaviours during loading onto a float. We conclude that providing stabled horses with one hour per day of exercise on a walker, treadmill, turn-out or by being ridden are likely to improve handler safety. The above forms of exercise for one hour are all effective at allowing the expression of locomotor behaviour in stabled horses, and if rebound behaviour is considered an indicator of previous behavioural deprivation, can be expected to have positive effects on horse welfare.