This low impact activity uses water as resistance to improve your strength, posture, flexibility and coordination while getting a great cardiovascular workout. Work at your own pace, whether you are a beginner, intermediate, or advanced level participant. While similar to land aerobics, in that it focuses on cardiac training, water aerobics differs in that it adds the component of water resistance and buoyancy. Although heart rate does not increase as much as in land-based aerobics, the heart is working just as hard and underwater exercise actually pumps more blood to the heart. Exercising in the water is not only aerobic, but also strength-training oriented due to the water resistance. Moving your body through the water creates a resistance that will activate muscle groups.