a new adventure in exercise

Ok so I have been off and on with exercising the past oh say 7 years. Recently I got back on the horse and really had been dedicated but then got sick. and thought I was dying so the exercise promptly stopped. Well today was my big day and I started with jump roping. I read in my Women's magazine 15 minutes to fitness guide that a good cardio session is to jump rope for 15 mins and do strength training after for 15 mins. well at around 12 mins of hop hop hop i fell the ground exhausted. I thought my heart was going to explode. Geezas. Im out of shape but man, jumping rope kicks ass. I highly recommend it.