Female horseriders who fail to wear a sports bra could be causing distress to their animals, a study by Portsmouth University finds.

A survey of riders discovered that fewer than one in five women regularly wore a sports bra for riding even though it can lead to poor posture and musculoskeletal problems which are sensed by the horse.

Previous research has shown that horse heart rate increases in response to tension in the handler or rider.

Dr Jenny Burbage, of the Department of Sport and Exercise Science said: “A correctly fitting bra for exercise is essential, as an incorrect fit can contribute to upper body musculoskeletal problems, poor posture and deep bra furrows in the shoulder caused by excessive strap pressure.

“The physical application of cues to the horse relies on good postural control by the rider, which can be negatively impacted by pain or discomfort leading to postural asymmetry.

“The ridden horse is trained to respond to subtle cues given by the rider’s body, but as a species can detect and respond to physiological changes that the rider may be unaware of.”