'the sports'

Very often I’ll ask my flatmate Sebastion what he did with himself over the weekend, and he’ll respond by saying he did ‘the sports.’ Likewise, when I return from a run, he’ll ask if I just got back from doing ‘the sports.’ Apparently, as far as althetic activities go, Germans do not make any distinctions—anything from jogging to swimming to soccer or even going to a sauna falls under ‘the sports.’ We asked Dave’s German friend Christoph about this (who, I should add, refers to his math homework as ‘the maths’) and he confirmed that in German, there is only one word that refers to althetic activity. I did try to explain the difference between playing a sport and exercising to Sebastion, but he continues to use his catch all phrase ‘the sports.’