Apprentice jockey Dominique Webb was punched twice in the face by a dog walker who objected to her riding on a footpath.
Stunned Dominique, 19, was left with mild concussion and shock after the attack near The Gallops in Lewes.
She said: "I don't understand why some people have to be like that."
Dominique, who lives in Hailsham, had been exercising her boyfriend's horse, Royal Tradition, and was riding back to Windmill Lodge Stables when the attack happened.
The dog walker, aged about 60, took offence at her using the footpath and hurled insults before grabbing Dominique's legs.
She said: "He swore at me and tried to pull me off. I explained to him we had permission from the landowner to use the footpath and there was a big field alongside. There was plenty of room for everyone."
Dominique moved out of the way and walked back to the stables.
The man followed and began shouting at her.
"He was spitting at me and calling me names and then he punched me twice in the face."
The man fled after other staff intervened and Dominique later received medication from her doctor after she complained of headaches and nausea.
The attacker was white, 6ft, with grey hair, wearing an anorak, trousers and walking boots. He was with a small terrier-type dog.
Anyone with information should call Sussex Police on 0845 6070 999.
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