How good is punching bag compare to running or cycling for cardio? which one demands more intensity and makes you lose more calories, I have some cash to spend on either, a punching bag, treadmill or a bicycle, thank you.
i would buy a bicycle personally. you want to spend life OUTDOORS. it is more fun and you can bicycle different places and with people. a punching bag or treadmill will end up collecting dust in a hurry because you will get bored.
Whatever you enjoy more is going to be the best choice. You are much more likely to stick to it when you have fun. In the end, anything that has your heart rate up is cardio.
The goal of cardio is simply to burn calories. It really doesn't matter what you do. Anything that gets you moving and gets your heart rate up is great.
Do whatever you like best. The only bad cardio session is the one you didn't do. If you like using a punching bag - then by all means. Use that as your form of cardio.