Can I replace my 15 minute treadmill with 15 minute beating on a punch bag? Because boxing a punch bag is actually very tiring and I sweat like crazy, or should i do a split of 10 minute jog 10 min boxing for cardio?

Go right ahead; make your cardio fun. It doesn't have to be boring. You can punch a bag like you said, ride a bike, play some basketball, swimming. If I am in the mood for any activity I usually get a football game going.

Anything that elevates your heart rate and beathing for an extended time period is cardio, but generally activities that make use of the largest muscles (glutes, quads) of the body are most effective. There also is a train of thought that, from an evolutionary standpoint, running upright is what the human body was most designed for and therfore running is the most effective exercise, so any activity that involves running a lot like the treadmill, basketball, soccer, etc. is most effective.

Of course, the most effective exercise is the one you will do consistantly, so I agree, go ahead and make your cardio fun. I also agree that changing up your cardio is good, so 10 minutes of each is probably better than 20 minutes of either.

Definitely no problem doing your cardio on a punching bag, as long as your keep your HR up. Oh - and remember to keep your hands up and feet moving. Hehehe!

For those who want a more 'full body' cardio experience, feel free to kick the bag. Or knee it. Or elbow it...

Boxing/ punching a punch bag/pads...cannot beat it!

Its the no1 thing that can have me on the floor because it can tire me so much. Im getting a punch bag on payday, cant wait

I do quite a bit of this and love it.......much more entertaining than using the treadmill and works me harder.

I like to imagine my enemies on the bag

not only is it a lot of fun, but a lot better for you. if you are doing mindless work on a treadmill, your mind may not be focused on the workout, so you aren't getting the full benefit. also, yes ... it is a lot more tiring. when i was in college, i dropped my weight training completely (5 x week, 90min each) for kickboxing (2 x week, 90 min) and i was in the best shape of my life (oh, the good times).

I am intrigued!!
I was looking up punching bags on eBay, and you can get one for roughly 20 bucks after shipping - is this going to be a good bag? As long as it says "heavy" or "heavy duty"??
Also, as far as filling it - I read somewhere to line the bag with carpet padding, and then fill it with garbage bags of sand, each weighing 5-10 pounds or so... does this sound right?
Are there any routines to follow on the internet anywhere? Or do you just punch and kick away, making it up as you go?
Thanks for the idea!!!!
Jon

Personally, I would try to get a long bag so I could incorporate some kicking as well.

Not sure of any technique websites but for me kicking and punching technique is crucial not only for power but for injury prevention. I would try to read up on this before getting into it.