If you *just* want to burn 4 sessions and come away with something useful, find someone who is EXPERIENCED working with athletes and have them set you up with some plyometrics to help you develop power. Power is what gets you up the 400th small hill FAST, not just alive, or allows you to sprint around the guy who's swimming style most resembles a weedeater.
If you've not done plyos before it's a great way to kick yourself in the tookus (sometimes literally!) but you should have someone on hand to evaluate and correct your form before you go off half-cocked.
If they don't have anyone who's got that kind of experience, from the sounds of it you might as well be training them.