Sports are really good thing to keep active (obviously). A workout you could try is this: dynamic stretches, 25 hip bridges, 6 timed planks (2 per each side, 2 low, and 2 high), 30 squats, 3 one minute jumps, 15 push-ups, 3 one minute Russian twists, 15 more push ups, 100 crunches, 3 one minute bicycles, 50 sit-ups, 3 3 minute Pilates boxing, and end with some stretches That is a really good core workout, and it works some other muscles too!
Pilates, yoga, planks, Russian twists with weights, squats, lunges
Hey! I'm also a 16 year old female and I bought a treadmill just before Christmas and it is the best thing I have ever bought! I use I every day after college! I go power walking with a few of my friends too so I get to exercise and socialise! I also downloaded a app on my IPhone that is a 7minute work out. You play it and it tells you what to do from skipping, squats, plank, push ups etc, a minute per each one. I started by doing it once a day but now I do it three or four times before and after my treadmill. Depending on how much excercise you do already it's best to start gradually and build it up, a little more each day. If you are looking to tone up then squats and planks etc are great and if you are lookin to loose weight then don't get down hearted that when you start excercise your weight loss doesn't seem alot because muscle weighs more! Good luck! Hope this helps!