Mariah Carey is known for her great curves and muscular body. Her personal trainer says that they have built her routine around Mariah's love of water. She does over an hour of swimming and water aerobics each day! Water aerobics are great for building muscles without putting too much stress on your body. Here are two of her favorite moves: When in the shallow area of the pool, hold your arms to your sides. Raise your hand straight in front of you to shoulder height and then lower it back to its start position. Water’s resistance exercises the muscles of arms and chest. Perform a set of 10 reps. Grip swimming pool’s sides and raise yourself up like you want to get out of the pool. Perform a set of 10. The exercise works the arms and chest muscles.