Vintage Au Coton Exercise T-Shirt

Au Coton is making a come back but vintage is always best :) No tags but I believe it's cotton, or at minimum, a cotton blend. There is some light pilling throughout. I'm not sure if the sleeve hem was cut by previous owner or came like that but it adds to the aesthetic. My guess is a size small but see measurements below. Shoulder to shoulder: 42cm Armpit to armpit: 45.5cm Length: 58.5cm Je parle français :)