Are there any good workout routines that build muscle w/o weight lifting?

I am 14 and am a pretty scrawny kid but I want to build muscle w/o using heavy weights. I hate lifting so much, it's just too dull to keep myself motivated. Any fun workout routines (aerobic, etc.) that help build muscle quickly without the use of heavy weights? Thanks in advance.
I was kind of joking when I said scrawny. I'm just skinny.

Public Comments

1. Pilates and Yoga. Do pushups and cruches, use your body's weight. Your 14, you dont need to build tons of muscle. Eat protein too to bulk up

2. well u can do push ups for ur chest/bicep/tricep, air bike for abs , arm circles for shoulders ,shrugs with something in ur hand for traps,squats for quads,and lunges for hamstrings.you can do all these without weights.this is coming from a 13 year old .hope this helps :D

3. Aerobics and such will tone, but not build much muscle, and not quickly. The best way with no weights is to use your own body weight. Situps, crunches, dips, leglifts, pushups, pullups. A cable type machine is the next step up, one that can allow multiple angles of crossovers and extensions. After that is machines that require weights, and then free weights.
If you stick to ty-bo or aerobics you will stay scrawny, just get a cut look.

4. You can find a lot of information on building muscles at http://www.toloseweight.org/muscle.html