Possible Clues:

• Doctor replacing first item of communication mounted competition
• Preparation of horse for time under cover
• Training horses to finish before time
• Groom needs time for horse training
• Get on after groom in equestrian event
• Groom on time as horse moves
• Art of training horses
• Equestrian event which means “training” in French
• Riding activity
• Get up with nearly all the characters in 10 across for Arabian display, for example