Cycling on k especially at night with some earphones in and whatever tunes floats your boat. great experience, concidering you know the paths that your on well and have the courage to cycle literally into the darkness. Feels like a roller coaster. But here's my real question and it's been on my mind every time I do it. cycling on k is so easy because you don't feel the strain the same way, you can go up big hills and such with such ease but.. It's bound to be unhealthy for my muscles? I'm not worried about my heart and any strain there but exercising on a tranqulizer, it's bound to do damage no? I have tried to find an answer to this a fair few times but have never got a definitive one.