I was an avid soccer player for the better part of my 26 yrs. I suffered a torn hip flexor when I was 16. Went to physical therapy for a year. I had to quit playing as a result at 18. Now at 26, I am looking for an exercise program that would not aggravate my injury, which still aches from time to time. I do not like to use machines and prefer aerobic activities. Not looking to build muscle, just tone. Thanks for your advice!