Make Swimming Your Summer Workout

Summer is here and you’ve decided this is the year to trade your running shoes for a pair of swim goggles. Maybe you’ve tweaked a knee and need a lower impact form of cardio, maybe you just can’t face your outdoor boot camp class when it’s 90 degrees. 

Whatever your reason for taking to the water, swimming is one of the best exercises you can do for your health. It’s a total body workout, taxing your arms and legs, as well as your cardiovascular system, yet it puts less stress on your joints than most other exercises. And on a hot summer day, the cool water is a good place to get sweaty.

According to Hirofumi Tanaka, a professor of kinesiology at the University of Texas at Austin, swimming provides similar cardiovascular benefits as running or other endurance sports. Research at his lab also suggests a regular swim program can lower blood pressure and soften stiff arteries in older adults.

“Swimming is really an underappreciated, sneaky good form of exercise,” Dr. Tanaka said. “Exercise needs to involve large muscle groups, be rhythmical in nature and it should tax cardiovascular functions. Swimming fits perfectly.”

But where to begin? Facing down a lap lane can be intimidating as a novice. Below are some tips from professional coaches on how to turn 30 minutes at the pool into an effective workout.

Start slow.

“You wouldn’t go right out and say, ‘I’m going to run 10 miles,’” said Cokie Lepinski, a U.S. Masters Swimming coach in Surprise, Ariz. “Same thing with swimming.”

Buy a good pair of goggles (a swim cap and kickboard can be helpful but aren’t necessary), and start by swimming one lap — down and back the length of the pool — without stopping. Typically, people swim freestyle when they exercise because it’s the most efficient stroke, but you can switch it up if you have a strong preference or want some variety.

If one lap feels easy, do two with a short break (10 to 20 seconds) in between. Gradually build up, increasing the number of laps and decreasing the frequency of breaks, but don’t overdo it on your first day — no more than 10 laps total.

“When it comes to swimming, it’s about consistency, so start from where you are,” said Cullen Jones, a four-time Olympic medalist who coaches youth swimming. “Make sure that what you’re doing is manageable. Have the mind-set that you can do it again the next day or two days from now.”

Focus on form.

If your last swim lesson was in grade school, here are a couple of tips to keep in mind. First, you want your body to be on top of the water as much as possible. The easiest way to do that is to keep your head down and look at the bottom of the pool.

“If you lift your head up and you look at the wall,” said Fares Ksebati, a founder and chief executive of the swimming app MySwimPro, “your legs are going to sink, and that’s going to create a lot of resistance.”

Your kick also helps you stay balanced on top of the water. In fact, unless you’re sprinting, kicking is more important for body position than for propulsion. Kick just enough to keep your hips and legs on top of the water so they don’t drag you down. “The biggest mistake beginner swimmers make is they kick too much,” Mr. Ksebati said. “The legs use the most blood, so if you kick a lot, you’re going to fatigue a lot more quickly.”

If you’re racing, then you can kick your legs into high gear, as Mr. Jones did in the 50-meter freestyle sprint at the 2012 Olympics. But when swimming for endurance or general fitness, imitate someone like distance swimmer Katie Ledecky, whose legs barely make waves, to conserve energy and focus more on balance and alignment.

Another mistake beginners make is staying too flat in the water. Instead, you want to rock subtly from side to side. As your fingertips touch the surface, extend your arm as far as you can while rotating your hips and shoulders slightly. Try this on dry land: stand on your tiptoes with one arm stretched overhead. If you shift your hip and shoulder upward and forward, you can probably reach a few inches higher. Now do that in the water.

“If you can start to rotate with your shoulders and your hips on every single stroke and reach a few more inches, you’re going to basically lengthen out your stroke, and that’ll make you more efficient,” Mr. Ksebati explained.

Another way to increase your efficiency is to create more force with each stroke. As you pull your arm down through the water, try to get your forearm perpendicular to the bottom of the pool. Your fingertips should be separated slightly — less than a centimeter — to get the most power.

Don’t worry about breathing on alternating sides if one feels more comfortable than the other. The goal is to keep a rhythm. “Every time your face is in the water, you’re exhaling,” Ms. Lepinski said. “Every time you come up, you’re having a nice, measured inhale.”

Get into intervals.

Once you can do eight laps easily, try some interval training. For serious swimmers, workouts are structured like weight training, broken into sets rather than going for 30 minutes straight.

To do this, you need to understand an interval formula used in almost all swim workouts. Intervals are usually described by two numbers: 1) the number of repetitions and 2) the distance in yards of each rep as a multiple of 25 (the length of the pool). Short rests are built in after every rep. For example, a 2x50 means swimming 50 yards (down and back), taking a 10-second break, and then swimming another lap. For a 4x25, swim the same distance, but rest every time you touch a side. A 1x100 means swimming two laps continuously and resting after. All three intervals are 100 yards total, but they’re swum at different rates.

“If you swim the same pace every day,” Ms. Lepinski said, “you won’t get as much benefit.” For one, she added, interval training is more fun. “And two, it just challenges your heart a little bit better.”

Mr. Ksebati and Ms. Lepinski said a good beginner or intermediate workout is 1,000 to 1,500 yards, or 20 to 30 laps, which should take about half an hour. Begin with a short warm-up — maybe a 4x50 at an easy pace — to get your heart rate up. You can mix in different strokes, doing breast or backstroke instead of freestyle for a little variety. Next do a 4x25 using a kickboard to get your legs activated.

Then comes the main set, or the bulk of your workout. If you’re working on speed, do 8x50 (eight laps with a break after each) at a fast pace. If you want to increase endurance, try a moderately paced ladder, ascending and then descending the length of your intervals: 1x50, 1x100, 1x200, 1x100, 1x50.

Last comes the cool-down, another 4x50 of swimming at a relaxed pace. You can take a longer break — one or two minutes — in between the warm-up, main set and cool down.

It’s a little confusing at first, but once you get the lingo you can follow almost any swim workout. Want even more structure or a goal to work toward? Apps like MySwimPro provide customized workout plans, or you can find your local U.S. Masters Swimming team. (In the swimming world, “masters” just means adult.)

Most of all, enjoy the process. For many swimmers, the water isn’t only a place to work out, it’s also a sanctuary. “It’s hard to be thinking about the stresses of the world when you’re thinking about, ‘When’s my next breath? Where’s the end of the pool? What set am I on?’” Ms. Lepinski said. “When we slip under the water, the world goes away.”

Dana Smith is an award-winning health and science writer based in Durham, North Carolina.

A version of this article appears in print on June 7, 2022, Section D, Page 6 of the New York edition with the headline: Swimming as a Summer Workout. Order Reprints | Today’s Paper | Subscribe