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by Kris Goodrich

May 5, 2021

These workouts will help you work your core to achieve a more efficient body position and increase your speed

Your core is the foundation for everything in swimming. Strength through your core means that your stabilizer muscles keep everything in line while the larger muscle groups work together to power your kick and pull. Your core connects the parts of your body: front to back and top to bottom. For freestyle and backstroke, a connected body means you get more power for rotation. Breaststroke and butterfly depend on the core for flexibility and power for undulation. Understanding your body as connected parts often translates to faster and more efficient swimming.

When most people think of having a strong core, they believe that means doing a lot of crunches or sit-ups. Often neglected are your back muscles. Overworking one side and skipping the other side can lead to imbalances and injury. Think of your core as all the muscles from your hips to your shoulders on the front, sides, and back of your body.

These workouts use your abdominal muscles, your oblique muscles on the sides of your body, and the muscles in your back. They challenge you to use your core to swim with great body position and think about maintaining that, even at the end of a long workout.

Workout 1: Rotate

Freestyle and backstroke are often referred to as the long-axis strokes because you’re rotating your body along a line through the length of your body. Think of your body as a shish kebab on a skewer—your head, hips and toes always stay on the skewer and rotate side to side as you swim.

  • By alternating swimming between the two strokes in this workout, it helps you to feel the rotation similar to both.
  • Try to think of the rotation coming from your hips in freestyle and shoulders in backstroke to really focus on the core work on both sides of your body.
  • If you’re lucky enough to have a lane to yourself, the line on the bottom of the pool is a great guide to keeping your body straight (on the skewer) as you rotate.


200 freestyle on :05 rest

200 pull on :05 rest

200 kick on :05 rest

4 x 25s freestyle on :45

(Build each 25 slow to fast)

Main set

400 freestyle

(150 freestyle 100 backstroke 150 freestyle)

400 freestyle

(Swim 400 straight, work on body position)

400 freestyle

(200 freestyle 100 backstroke 100 freestyle)

2 x (2 x 100s kick on :20 rest + 200 pull on :20 rest + 100 choice on :20 rest)


2 x 50s freestyle on 1:00

(Reverse build fast to slow)

200 freestyle

Total: 3000           

USMS members can view this workout and hundreds more in our Workout Library

Workout 2: Undulate

You’ll often hear the word “undulate” from coaches to describe the wave-like motion that powers your butterfly and breaststroke. It starts with pressing your chest in the water, flows down through your hips and legs, and finishes at the tips of your toes.

  • Imagine a wave that rolls down a towel when you snap it—that’s the motion you’re trying to accomplish with your body. In order to make the wave uniform, you need to use both the front and back sides of your body.
  • This workout below incorporates dolphin kick on your front and back. Pay attention to the energy sent both up and down as you kick in different positions. Do you have a stronger kick on your back kicking up? Work on making both equal and using your core, not your knees, to initiate the kick.


200 freestyle on :15 rest

200 pull on :15 rest

200 kick on :15 rest

100 choice on :15 rest

4 x 25s freestyle on :15 rest

(Build each 25 slow to fast)

Main Set

4 x 250s freestyle on :15 rest

(100 pace, 50 dolphin kick on back, 100 pace)

4 x 100s pull on :10 rest

3 x 100s kick on :10 rest

(25 flutter kick, 50 dolphin kick core focus, 25 flutter kick)


4 x 25s choice on :10 rest

(Reverse build each 25 fast to slow)

100 backstroke on :10 rest

100 freestyle

(Nice and slow)

Total: 2800           

USMS members can view this workout and hundreds more in our Workout Library

Workout 3: Swim Tall

Swimmers with lower stroke count per length, 12 or below in a 25-yard pool in freestyle, tend to have better body position and core strength to glide through the water in between strokes. Drag forces are a swimmer’s worst enemy. Learning how to swim tall, stay straight, and have good balance between every stroke can also help to decrease drag forces and increase your swimming speed.

  • If you’re not sure of your stroke count (how many times each arm moves per length), use the 400 warm-up in this workout to figure it out.
  • During the main set, you’ll be using your core to maintain your balance as you lengthen your stroke. Every time your hand enters the water, think about reaching through your hips, and stretch tall as you initiate the catch and pull.
  • Maintain a neutral pelvis, keeping a good body line and use your core to rotate around the long axis and glide through the finish of each stroke.


400 choice on :15 rest

4 x 75s choice on :15 rest

(25 kick, 25 drill, 25 build)

Main Set

Settle in as we hit a few 500s working on distance per stroke, breathing and pacing.

500 freestyle on 2:00 rest

(Alternate breathing to opposite sides by 50)

500 freestyle on 2:00 rest

(With snorkel and paddles, focus on distance per stroke)

500 pull on 2:00 rest

(With paddles, no snorkel. Breathe every 3-5-7-5-3 by 100)

500 freestyle on 2:00 rest

(With paddles and fins, descend by 100s to fast)


200 Choice on 4:00

Total: 2900           

USMS members can view this workout and hundreds more in our Workout Library

Workout 4: Stay Tight

Have you ever watched swimmers who seems to wiggle side to side as they swim? Their head may be straight, but as you watch their legs and toes, they twist from the hips, and, instead of rotating, they angle their toes out to the side walls with their thighs still pointing down. What they’re lacking is the core strength, or connection, to have their body stay in that straight line from the top of their head to the tips of their toes while swimming. Another sign of this is when their hips tilt and belly sags down while swimming instead of keeping their pelvis in a neutral position and belly and back flat in the water. 

  • This workout uses a pull buoy in several different spots: at your ankles and at your knees. To swim with the buoy at your ankles takes quite a bit of core work to keep your pelvis neutral.
  • When you make the switch to buoy above your knees, after focusing on keeping your pelvis in line, notice how much easier it is to rotate without your legs swinging to the sides.
  • To really keep a good focus on body line during the workout, try using a snorkel during the pull sets.


400 choice on :15 rest

4 x 150s choice on :15 rest

(50 kick, 50 drill, 50 swim)

Main Set

Use the pulling as your recovery on this set of 50s and pulling mix. As the interval goes up, your times should get faster. Swim this straight through unless a rest is given.

400 pull on :30 rest

(For 1st 200, hold buoy at ankles)

8 x 50s choice on :45

(Choose interval that gives :05–:10 rest)

300 pull on :30 rest

(For 1st 100, hold buoy at ankles)

6 x 50s choice on :50

(Choose interval that gives :10–:15 rest)

200 pull on :30 rest

(For 1st 100, hold buoy at ankles)

4 x 50s choice on :55

(Choose interval that gives :15–:20 rest)

100 pull on :30 rest

(Long and relaxed)

2 x 50s choice on 1:00


200 choice

Total: 3200           

USMS members can view this workout and hundreds more in our Workout Library

Workout 5: Quick Turns

Executing flip turns and pushing off the walls properly require strong core muscles. Getting your knees tight into your chest and flipping over quickly are a function of core strength. When pushing off the wall, keeping a neutral pelvis and tight core help to keep your push-off directed at the opposite wall as opposed to the bottom of the pool or the surface of the water.

  • This workout has a turn set during which you practice turns at both walls. Think about using the strength of your core to get your knees to your chest quickly as you flip over, then maintain that strength throughout the push-off.
  • There are some dolphin kicks in this workout as well, for a little bonus core workout.
  • This workout is for working on getting off the wall underwater and adding a dolphin kick or two. Keep your head down as you come off the wall. You should not be able to see the other end of pool as you come off the wall.


150 freestyle on :10 rest

150 pull on :10 rest

150 kick on :10 rest

100 freestyle on:10 rest

100 pull on :10 rest

100 kick on :10 rest

Main Set

2 x 250s freestyle on :15 rest

(2nd and 4th 50s are sprint)

4 x 50s freestyle on :15 rest

(Start in the middle of the pool so you do two turns with this set)

100 freestyle on :15 rest

(With every turn, get at least 2 dolphin kicks off the wall)

2 x 200s pull on :15 rest

200 kick on back on :15 rest


100 freestyle on :10 rest

(Work on getting off the wall with 2 dolphin kicks)

200 freestyle

(Nice and easy)

Total: 2950           

USMS members can view this workout and hundreds more in our Workout Library

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