Traynor rejected claims soccer was a foreign sport calling it "a Celtic game, pure and simple, having its roots in the Highlands of Scotland.

"[2] Traynor joined the Irish Volunteers and took part in the Easter Rising in 1916, being the leader of the Metropole Hotel garrison.

During the Irish War of Independence, he was brigadier of the Dublin Brigade of the Irish Republican Army and led the attack on The Custom House in 1921 and led a 12 man squad in an ambush on the West Kent Regiment at Claude Road, Drumcondra on 16 June 1921 when the Thompson submachine gun was fired for the first time in action.

He organised guerrilla activity in south Dublin and County Wicklow, before being captured by Free State troops in September.

[6] He was re-elected as one of eight members for Dublin North in the June 1927 general election but just one of six Sinn Féin TDs.

Traynor did not contest the second general election called that year but declared his support for Fianna Fáil.