Aged sixteen, Martin Longden made a single first-team appearance for Exeter City playing in one of the club's first matches in the newly-inaugurated Football League Trophy against Newport County on 18 August 1982.

Growing up in Weston-super-Mare, Martin was offered an apprenticeship by Bristol City but turned down the opportunity due to the uncertain financial state of the club at that time. Fortunately the young centre-forward's talent caught the eye of Exeter City coach Alan Beer who brought him to St James Park, where signing as an apprentice in July 1982, Martin quickly settled and began training with the first-team squad. Martin got his chance in the first XI much earlier than expected filling the boots of an injured Tony Kellow in pre-season games against Leicester City and Torquay United. In these games Martin - fresh out of school - played against opponents such as Alan Smith and Gary Lineker (Leicester) and Torquay United's player-manager Bruce Rioch who, Martin recalled, "kicked the living daylights out of me for ninety minutes and then shook my hand at the end" 

Martin’s official debut for the Grecians came just weeks later and, at sixteen-years-old, he still ranks as one of the younger players to have appeared in City’s first-team. Facing Newport County, in the early-season group stages of the still-new Football League Trophy, it was far from a dream debut as City lost heavily thanks to a John Aldridge hat-trick. Despite the promising start Martin did not make another appearance and left the club in May 1983, his progress having partly slowed because of a hernia injury. 

Declining the offer of a monthly contract, Martin returned to Weston before joining the Royal Air Force as a trainee physical training instructor. Whilst in the RAF Martin switched to rugby union and played for Bedford, Bristol and Weston-Super-Mare until hanging up his boots at the age of twenty-seven. Leaving the RAF, Martin joined the police and worked as a detective before moving into a training role. Remarkably one of his later trainees was Mark Kendall who had been Newport’s goalkeeper on the occasion of Martin’s single professional game. After retiring from the force Martin ran a sportswear business in Weston.