Hello Q Great question. When first beginning Pilates we take you through fundamentals- reintroducing your neuro to your muscular. Precision is key!. Pilates is about quality movement with flow. So, in the begginning NO- keep up with your cardio outside your Pilates program. In a Position Statement from the PMA- Pilates was not designed to be aerobic nor did Mr. Pilates claim that it was aerobic. Recent research shows that Beginner Mat Pilates is low-moderate intensity and Intermediate to Advanced Mat does meet the criteria for moderate activity. Once you become advanced I would say Yes, Pilates is a moderate activity. I would not consider it personally a true full blown aerobic activity such as running, cycling, or the Elliptical Trainer. There are classes that offer jump board as an accessory on the reformer—this is so much fun and is considered a definite aerobic workout! You would have to find someone who offers this program- it is not really a purist practice. Kind of like a mini trampoline lying on your back. It is great for practicing ballet positions and jumps. I hope that this helps- Please see the PMA web site at www.pilatesmethodalliance.org It is a wonderful sight that gives you the low down on all that is Pilates! :) Wishing you fun and health in all of your movement experiences! Cynthia