Ever wonder about that indoor cycling class at your gym? Often done in a dark room with people pedaling in place? These can be an amazing low impact cardio workout or an accident waiting to happen. It all depends on the instructor and format of the class. If an instructor keeps it real by mimicking outdoor riding situations (hills, endurance runs, sprints/pace pickups) you can get in a quality workout. If you’re an outdoor cyclist you can train in bad weather. If however the instructor is doing pushups on the bike or other such nonsense run far, far away and never look back. Small hand weights? RUN! The bike is for riding and riding only. If you are doing anything else you are putting yourself at high risk of injury. As soon as you start playing around with your upper body on the bike, you lose focus on the legs which can lead to knee, hip or lower back injury. Plus, the amount of weights used will not get you any results on your upper body. Jennifer Sage has written several great articles on the topic including this one. Anyone showing you their new found upper body muscles from a cycling workout is merely showing the results of the caloric burn. Less fat = more muscles showing. They did not develop or gain these muscles on the bike.
So, ride on my friends. But ride smart. Just ride. Find a good instructor and have some fun in a safe and controlled environment.