A stalker used the free fitness app Strava to track the whereabouts of his victim, a court has heard.
Timothy Mills, 60, accused Emma Lord, 49, of being with another man after tracking her on the application.
A court was told Mills sent her more than 80 messages on Facebook and 20 texts in a two-year period.
Mills met Ms Lord, a mother of two, at a running club in Macclesfield, Cheshire, and over time started confessing his love for her, as well as leaving roses and letters at her home.
Mills accused Ms Lord of having a relationship with another runner because their Strava profiles showed them going on runs at the same time. The app logs exercise routes and times.
In fear of bumping into Mills, Ms Lord quit running, a hobby she enjoyed doing three times a week, Warrington Magistrates' Court was told.
But Cheshire Police are still considering whether to bring criminal charges and have had an a application for an interim three-month stalking protection order granted.
The hearing was a civil case on behalf of the force, the Sun reports.
Mills claimed he is not a stalker.
The order means Mills is forbidden from contacting Ms Lord, who works in HR, nor can he approach her or give her any gifts.
Macclesfield Harriers has reportedly suspended Mills's membership and UK Athletics has suspended his coaching licence.
