Building endurance for swimming cannot be rushed. It takes dedication and perseverance for a swimmer to develop proper breath support and muscle memory to draw upon when swimming for long periods. By swimming different drills that focus on speed, form and endurance, your swimming style will improve and you will be able to swim longer distances more efficiently. For a beginner, swimming three or four times per week for shorter durations will build your endurance faster than swimming for longer, less frequent sessions. Once you are a seasoned swimmer, training two or three times per week is sufficient.
Breath Support and Rhythm
Exhale under water when swimming. Often times, people will try to inhale and exhale when they lift their head. By exhaling under water, you allow yourself a full inhale breath when you lift your head out of the water. Count your strokes. This will help you maintain a regular rhythm and keep your stroke length consistent. Keep your head aligned with your spine and look down to make your body aerodynamic.
Arms and Legs
Keep your legs together as much as possible. When you lift your head to inhale, touch your big toes together. Keep your elbow high as you pull through a stroke. Be sure to push through the entire stroke as much as you can. Begin by pushing firmly through five strokes, then pushing less for the next five strokes while maintaining your rhythm. Gradually increase the number of strong strokes with each endurance training session.
Form Training
Warm up by swimming one 25-meter lap, then one 50-meter lap. Swim three 25-meter laps focusing on the pull of your right arm through a stroke, using a pull buoy if desired. Swim three 25-meter laps focusing on the pull of your left arm through a stroke. Then swim three 25-meter laps, focusing on your kick and its effectiveness. While working on your kick laps, lessen the pull of your stroke but keep the integrity of the stroke. Cool down by swimming the warm-up pattern at a slow but steady pace. After three to four weeks, you will be able to swim this pattern easily. At that point increase the laps in 25 meter increments, up to 150 meters.
Endurance Training
Swim one 25-meter lap, then one 50-meter lap to warm up. Swim two laps, focusing on your pull and stroke. Swim two more laps, focusing on your kick. Swim a ladder exercise, beginning with 25 meters, then increase to 50, 75, then 100 meters. Decrease your swimming to 75, then 50 and lastly 25 meters, with brief rest periods in between. Cool down by swimming the warm up pattern at a slow but steady pace. Once you can swim this ladder exercise easily, increase the laps in 25 meter increments over time while decreasing your rest period.