DO I NEED TO DO CARDIO? OR CAN I JUST START TONING UP? *PICS*?

seriously, you don't need to be toning up. you aren't flabby when you crouch down. you're only 13 you don't need to be worrying about that just yet. when you turn 16 then you can start full on worrying about it. but, just jog for 10 minutes, and do it after your workouts.