Source When I was home for the summer after my first year at university, I started training for a duathlon. I bought a road bike and woke up before work every day to cycle 10-20 miles, and then went for a 3-5 mile run after work every day (I have no idea how I had the motivation; I keep trying to recreate it and it's not working so far...!). But, I was in the best shape of my life that summer. My legs especially, they firmed up so quickly and were so toned and strong. And my butt was in pretty good shape too (note the was ... haha). When I went back to Vancouver for college I didn't feel as safe cycling on the roads here - too much rain and traffic (and I'm not great in cold weather, either!), so I started to do indoor cycling - or spinning - classes as a way to keep up those muscle groups worked out in road cycling, so I could keep my times down.