Swimming is not just for relaxing on hot summer days -- it can be an intense aerobic workout that strengthens both your upper and lower body. If you regularly swim with a moderate intensity for at least 20 minutes, you will begin to see increases in your stamina and in your lungs' ability to deliver oxygen to your body. You can also maximize your aerobic gains incorporating high-intensity intervals into your workout. Consult your doctor before beginning swimming or any new exercise program.
Basics of Increased Stamina
You can see the benefits of increased stamina during your workouts as well as in daily life. Improving your endurance allows you to swim faster and longer, and it also allows you to easily fly up flights of stairs, run to catch a bus and generally be more energetic. The Sports Fitness Advisor explains how researchers typically measure lung capacity in terms of your VO2 max, which reflects the maximum amount of oxygen your lungs can distribute to your heart and muscles per minute of exercise. Your VO2 max increases if you stick with aerobic exercises such as swimming.
Effects of Swimming Regularly
Swimming intensely for long periods makes it a good aerobic workout. You should perform any aerobic exercise, such as swimming, at least three times a week for 20 minutes a session, according to the President's Council on Physical Fitness and Sports. Your cardiovascular system and muscles will begin to adapt to your exercise routine by getting stronger. Your lungs will also adapt by increasing their capacity, allowing you to take in more air and deliver more oxygen to your muscles.
Use High-Intensity Interval Training
You can tailor your swimming workouts to maximize the beneficial effects on your stamina and lung capacity. Doing your swimming in short sprints, known as high-intensity interval training, provides greater gains than steady laps. In study results published in 2007 in the journal "Medicine and Science in Sports and Exercise," Jan Helgerud and colleagues showed that men who did aerobic exercise in intervals of four minutes at 90 percent of their maximum heart rate and three minutes at 70 percent of their maximum heart rate improved their lung capacity more than men who only exercised at 70 percent of their maximum heart rate.
The Slow Component Factor
Your lungs' ability to use oxygen affects your stamina. Your body's oxygen efficiency, which is used to produce energy, is progressively lost although the you continue to exercise at the same speed. Called the slow component of VO2 max, this means that your lungs can deliver more oxygen than you need as you start swimming, but as you continue to swim, your body's ability to use oxygen becomes less efficient. This reduces your ability to continue exercising. By maintaining a regular swimming routine, you will gradually increase your endurance and decrease the slow component factor, which allows you to swim faster and longer.