The youth, identified as Nitish Kumar, son of a railway gangman, was arrested from his home, Jehanabad Superintendent of Police Shyali Dhurat said. He was produced before the Railway magistrate and sent to jail.
Ashwani Raj was returning home here after attending a training programme in Gaya, when three to four youths, who alighted from the same train, accosted her and started beating her up when she protested.
The youth allegedly regularly teased the athlete, who was preparing for 5,000 mt race, which she used to ignore.
Admitted to the Jehanabad Sadar Hospital, Raj expressed apprehension that she might not be able to participate in the National Games starting in Gujarat starting from December 7.
The SP, who met the athlete, said she was recovering fast.