My 2011 Kagerō Fixie, absolutey love this build. I like fixies, I’ve noticed it works same muscles as running when controlling descents but easier on the joints and no coasting possible : ) …shhh its a secret. Not kidding, If you’re not a runner go run 6 miles and see how you feel day 2-3, record a base line and ride a fixie a week later up and down steep hills and see what muscles hurt day 2-3. I don’t like to run anymore for more than 3 miles so I ride a fixie instead. Its all about the cross training, ride, row, climb, swim, run, jump rope, yoga and or dance. Point is cardio and body weight exercise is all you need to maintain healthy life style and well above average fitness and 1 hour a day is all toy really need. Who doesn’t have 1 hour a day?