So I already got great advice on heart rate while working out. My new question is at the Y where I work out I have a variety of options for cardio. I have been putting in about 45 on the elliptical and 15 on the treadmill. Today I added 10 on the recumbent bike. My question is is there a suggested way of using the machines? Do I use one on one day and another the next. Do I do a few minutes on one and then another? How can each machine help or hinder me? I am coming from a pretty sedimentary life style. I was pretty religious at the gym from February - June of last year and then fell out of routine over the summer. I am back in the saddle but have a far path to plow. Next week I plan on adding the weights back in..... Any and all advise is so appreciated. I have signed up for a challenge at the gym for the next four weeks to work out four times each week..... Here I go!!!