If you want exercise you need a 'power' or 'traction' kite. Power' and 'traction' kites provide great exercise, better than the exercise during recreational flying or fun flying. So you need a large kite bag full of many different specialized kites. Sparred-parafoils are the fastest kites in the world. Tiny deltas on short lines are also really fast.
Big kites are slower than small kites.
The more expensive the kite, the higher its performance. So step up. And it's possible only with slow-moving kites. Advanced skill is needed for hot performance. For kiting on water, or when training for it, a control bar is best.