Re: Cardio and Weights together?
Getting lean has a lot to do with your nutrition. I do competitive bodybuilding so I know this from experience! Nutrition is 70% of the equation, exercise is the other 30%.
When I am leaning up I use rotational calories over a three day period. For example 1700 (high carb/low protein), 1800 (med carb/ med protein) & 1900 (low carb/high protein). I weight train 4 times a week and at the moment I am doing about 10 hours cardio per week. (Vary the cardio too, time wise and what you actually do. The body adapts if you do the same thing all the time)This will more than likely increase as my comp date approaches.
By the way being younger, you should be able to lean up heaps easy!
Hope this is of some help!