Water 3: Water Aerobics is a class is for men and women ages 18 years and older who want a higher intensity water workout. This class is appropriate for people who like aerobics exercises at a gym in general. Water 3: Water Aerobics provides a fun and safe physical workout for people to stay fit and healthy.   Water 3: Water Aerobics is a pool workout that incorporates cardio exercises and strength-training exercises in the water. This class is similar to HydroHIIT but not every class includes interval training; it might instead be a steady-state cardio workout. You'll use every muscle group in each class, with a lot of core work in the pool.