I’m having fun bouncing on my Marcy cardio rebounder. I can run myself out of breath several times a day without my knee acting up. I like working out at night and especially like not having to leave the house to do it. I like the rebounder better than the treadmill and studies show it burns more calories. I don’t care so much about calories as I do about getting quality aerobic time in and keeping myself strong. Aerobic = activity intended to improve the efficiency of the body’s cardiovascular system in absorbing and transporting oxygen. I’m all about improving efficiency!