Hi. I'm 15 years old and need some help starting up a fitness routine? I already play quite a bit of sport and sometimes go to a gym, but I have now proper plans on how to build up m muscles and to incease my stamina. Anybody care to help?

I've taken your advice, and I've read around some
So my fitness plan goes something like this...
Monday - Cardio, 25 crunches (4 sets), 10 pressups (3 sets) and steups for 3 mins
Tuesday-Gym, 2000 metres rowing machine, sets of 15 with dumbells for biceps (4 sets) and also sets of 15 with dumbells for chest
Wednesday - same as monday
Thursday - same as tuesday
Friday - same as monday
Saturday/sunday sport and running

Does this sound like a good regime? are there thing i should be changing if i want to be increasing my stamina? I'd also like some tips on increasing my arm muscles if theres something else i should be doing?

Thanks

To be honest, it looks to me like you read what was available and ignored everything that didn't fit with what you randomly decided was good and/or have seen the local monkeys at the school gym doing.

Try again. Focus on balance. You should probably consider, for weight training, a full body program consisting primarily of compound movements 2 or 3 times a week. I'd recommend Monday and Thursday on your schedule. Also, and you can get different opinions on this but, I'd recommend doing cardio after weight training. You really need to read more, and carefully.

Since this question will be asked a million more times, the best answer is always this:

Get yourself the greatest book ever written on weight training. Beyond Brawn.

Muscle Growth Guaranteed!

He has many other books, but I cant recommend them, as I have never read them. I have heard only good things about them though.