Active outdoor lifestyle in BKK? (Bangkok)

....while working full-time, no less. Is it even possible?
I moved back here for about a year now. To me, the urban life is kinda fun and exciting for the first 3 months or so. But after 100s nights out while drinking what must have been my body weight in whiskey last year, I kinda miss being within 30 mins drive from mountain, river, ocean and forest.
All my local friends here are not really an outdoor type so the big city lifestyle fit them well. But I'm wondering what else is there to do in and around BKK that doesn't involve malls or nightclubs?