If you have any long, hard surfaces, you might try roller blading. Less impact and works additional muscles in the legs which can speed you to optimum heart rate. Alternatively, try cross country running as the softer ground is better for you in a standard shoe, or get a proper air or gel filled sole for hard surface running.
I've actually picked up a pair of barefoot (five toed, minimal sole) running shoes. Takes a bit to get used to, but I love it. Also, if you are going to be going to the gym, running mills will do in a pinch.
lol, yup... not too many changes at a time, like DB, otherwise you won't be able to tell what works and what doesn't.
