Sometimes called cardio, aerobic routines make the heart and lungs work harder to increase oxygen levels in the blood stream. Anaerobic exercise is the opposite of cardio exercise. When an exercise routine does not require rapid replenishment of oxygen, it is considered anaerobic. During anaerobic exercise the body uses energy stored in muscle. If you want to avoid cardio, focus on anaerobic activity -- try weight training, sprinting, push-ups or sit-ups.
Weight Training
Weight training involves the use of free weights or gym equipment to strengthen muscles. Engaging in a weekly weight lifting routine builds muscle mass and improves muscle tone. To avoid injury, the American Academy of Orthopaedic Surgeons suggests consulting a physician before beginning a weight training program. Choose a weight that will provide moderate resistance. Avoid weight that is too light or too heavy. Lift the weight until you've completed two sets of 8 to 10 repetitions.
Sprinters
Sprinters run at maximum speed for short distances. Unlike running, sprinting does not use oxygen as the only source of energy. When you sprint, available oxygen is depleted and the body uses energy stored in muscle to complete the exercise. According to "Physical Fitness and Wellness: Changing The Way You Look, Feel, and Perform", sprinting prompts the body to use other sources of energy, because there is not enough time to refuel muscle with oxygen. Try running for 20 yards at full speed, followed by a rest period. During the rest period, walk for 10 yards. Repeat the exercise until your muscles become fatigued.
Sit-Ups
Sit-ups target the abdominal muscles. When performing a sit-up, the rectus abdominis muscle contracts -- raising and lowering the torso. Because sit-ups use oxygen reserves without need for immediate replacement, they qualify as an anaerobic exercise. Perform sit-ups laying on the floor or on a stability ball. Lie flat on the floor with your knees bent and feet flat on the floor. Place both hands behind your head. Use the abdominal muscles to pull your torso upward. Do two sets of 8 to 10 repetitions. If you use a stability ball, get into the same position while laying on the ball. For better balance on a stability ball, the American Council on Exercise suggests spreading your feet apart.
Push-Ups
Like all anaerobic exercise, push-ups require a burst of energy. During a push-up, upper body muscles support your body weight. The Mayo Clinic notes that push-ups work the pectoral and tricep muscles. Lie stomach first onto the floor. Place your hands on the ground slightly more than shoulder-width apart. Use both arms to push your entire body off of the floor -- leaving only the toes at ground level. Do push-ups until your upper body muscles become fatigued.
