Christine Alexander is the author of 2 books on water exercise each published by Human Kinetics.
Water Fitness Progressions (2019) was written for water fitness instructors and aquatic personal trainers. It describes how to use periodization to help class participants and clients progress in their level of fitness. It contains lesson plans that illustrate how to progressively increase intensity for both cardiorespiratory endurance and strength training.
Water Fitness Lesson Plans and Choreography (2011) was written for water fitness instructors. It has 36 class ideas for shallow water exercise and 36 class ideas for deep water exercise. Individuals may find the exercise descriptions and photos useful for building a personal exercise routine.
All exercise is properly performed with the spine in neutral alignment. In deep water, good posture is more challenging to achieve because the feet do not touch the floor. Beginning exercisers may find themselves curling forward, flailing the arms, and drifting. There are some things you can do to stabilize. The most important is to wear a deep-water flotation belt. Without it, you will find yourself sinking when you attempt to achieve upright neutral alignment. Use a stabilizing scull, sweeping the hands in and out, to control flailing and reduce drifting. Webbed gloves further increase stability. Learn to brace the core muscles. Include tucks in the warm up (tuck ski or jacks tuck) to engage the core. With practice, the core muscles will engage continuously and discreetly throughout the workout, which is why deep water exercisers so often see improvements in their posture. Below is a list of basic deep water exercises with descriptions. Click on the name of the exercise to see a short video demonstration.
Scull. Sculling is an important skill in deep water. Besides assisting in stabilization, you can use a propeller scull (a figure 8 hand motion) to travel. Hold the hands up in front of you and propeller scull to travel backward. Hold the hands down by your sides and propeller scull to travel forward. Extend the hands out to the sides and use the scull to lift the shoulders out of the water. This works great with jog, heel jog, bicycle, and flutter kick. Maintain the elevation for 30 seconds or more to up the intensity.
Knee-high Jog, Sprint, and Power Run. Jogging is one of the most basic of all moves. Lift the knees until the thighs are parallel to the floor in a knee-high jog. Lifting the knees higher than that tends to make you curl forward and puts a strain on the low back. To increase intensity, go into a sprint by adding speed. To increase intensity even further, go into a power run, which uses large, powerful arm movements that pull the water, and longer, more powerful leg movements.
Heel Jog. Instead of lifting the knees in front, heel jog lifts the heels in back, working the hamstrings. Check to make sure that the knees are staying down.
Skate Kick. A kick backward with straight legs works the gluteus maximus, a muscle that tends to be weaker from sitting too much. Watch that you are not bending the knees and turning the exercise into a heel jog.
Crossover Kick. The midline of the body is an imaginary line that goes through the nose and the bellybutton. Crossover kick crosses that midline. Since the right side of your brain controls the left side of your body, and the left side of the brain controls the right side of your body, crossing the midline of your body requires using both brain hemispheres, causing more neurons to fire and making more connections. It’s a good idea to include some exercises that cross the midline in every session.
1. Skate Kick
2. Crossover Kick
3. Sweep Out
4. Center
Skate Kick, Crossover Kick, Sweep Out and Center.I love this exercise! It challenges coordination, crosses the midline, and engages the core. One leg kicks back, then kicks across the midline, sweeps out to the side and returns to center. Perform the move alternating right and left legs.
Cross-country Ski. Cross-country ski is the ultimate deep water exercise! It uses long levers, works both the upper body and the lower body, and gets the heartrate up. Plus, there are multiple variations! In a neutral position the arms and legs should go forward and backward evenly. If the glutes are weak, it may be difficult to get full hyperextension of the hips. If you tilt the trunk back and focus too much on hip flexion, you end up just kicking forward. Check out your form by skiing with your back to the pool wall; your heels should tap the wall. Try shortening your range of motion so that your forward flexion is not greater than your backward hyperextension. As the glutes get stronger you can increase your range of motion.
Cross-country Ski Travel Backward and Forward. Traveling backward with cross-country ski is a challenge. You cannot propel yourself backward by pushing off the floor. Instead your push yourself backward with a powerful forward arm swing. This takes upper body strength! Turn your palm to face forward when you swing the arm forward, and slice on the swing backward. Do the opposite to travel forward. Turn the palm to face back when the arm swings backward, and slices when the arm swings forward.
Tuck Ski. Instead of tucking your knees up, tuck your feet under your body. That way when you go into the ski your flexion (with the front leg) and hyperextension (with the back leg) will be equal. Watch that you don’t power pop the knees when you lengthen the legs. Tuck ski is a good exercise for the warm up or for active recovery between intervals.
Cross-country Ski
with Rotation
Cross-country Ski with Rotation. This is another exercise that crosses the midline of the body. The rotation is in the upper body, and therefore the arms reach across the midline, while the legs move toward the corners. This is a difficult exercise for some people to master. They end up doing a crossover kick while sweeping both arms side to side, or a crossover kick reaching with the arm on the same side of the body. It looks and feels awkward. But once the move is mastered, you can really up the intensity because the range of motion is so large, the movement is in multiple directions, and you are creating lots of turbulence.
Cossack Kick. My class likes this move. Begin with the heels together and the knees apart, in a diamond position. The shoulder blades are contracted with the elbows bent and the hands out to the sides, thumbs up. Now kick the legs out to the sides and at the same time reach the arms out to the sides. It looks a little like a marionette dancing.
Jumping Jacks. If you perform jumping jacks in deep water the same way you perform them on land, you will find yourself bobbing up and down. Performing them with arms and legs opposite solves the problem. Think of making a capital letter T with your body followed by a capital letter A.
Jumping Jacks Travel Sideways. If you want to travel sideways with jumping jacks you need a different arm and leg motion. Use only one side of your body. If you are traveling to the right, your right arm and right leg reach out to the side, then pull them both straight to center. Use the left arm and leg to travel to the left. Be sure to keep the leg straight, working the inner thigh. A common mistake is bending the knee, since short lever moves are easier than long lever moves. But this turns the move into a Cossack kick and works the hamstrings instead of the inner thigh.
Jacks Tuck. For this exercise tuck your knees up and bring your arms down to the sides. Then abduct the hips (bring the legs out to the sides) while lifting your arms to the side toward the surface of the water. Jacks tuck is another good exercise for the warm up or for active recovery between intervals.
Inner Thigh Lift.Begin with your legs wide apart. Lift one inner thigh toward the surface of the water while the opposite hand reaches down to touch the inner thigh. You can also touch the lower leg or even the ankle if you can reach it, but watch that you do not lean forward to accomplish this. It is more important to keep the spine in neutral than to touch the ankle. Work in your feel good range of motion. It is okay to bring the legs closer together if wide apart is uncomfortable for you, but if the legs are too close together the exercise becomes a knee-high jog.
Accelerate the Legs to Center Elevating the Shoulders. Elevation is a power move that begins with the legs apart, either front to back or side to side, followed by a forceful acceleration of the legs to center. As the straight legs come together the shoulders lift out of the water. There are four exercises that use this technique: cross-country ski with elevation, tuck ski together, frog kick, and breaststroke kick. All of them are great exercises to use in interval training.
Cross-country ski
with Elevation
Cross-country Ski with Elevation. Use your full range of motion for this ski, then forcefully pull the straight legs to center. Repeat. Repeat. Repeat.
Tuck Ski Together.Begin by tucking the feet under your body before going into a full range of motion ski then bringing the straight legs to center. Add some speed and perform the move smoothly. If you are a swimmer you will recognize this as a vertical scissors kick. For non-swimmers, a common mistake is going back into a tuck before the straight legs come together; this takes the power and elevation out of the move.
Frog Kick. This is another move swimmers will be familiar with. Begin by lifting the knees wide to the sides. Straighten the legs into a full range of motion jacks position. Then forcefully accelerate the straight legs to center. Again, a common mistake is tucking the knees back up before the straight legs come together, and then the move is essentially a jacks tuck.
Breaststroke Kick. Instead of lifting the knees wide to the sides as in the frog kick, lift the heels up in back. Then straighten the legs into a full range of motion jacks position and forcefully accelerate the straight legs to center. Both the breaststroke kick and the frog kick are lateral moves, but in the breaststroke kick the legs lift in back first and in the frog kick the knees lift to the sides first.
Side to Side. Begin by tucking your feet under you. Then extend both legs to one side in a side-lying position. Tuck again and extend both legs to the other side. Try to keep the feet close together. Foam dumbbells held out to the sides assist with stabilization for this exercise. It can be performed without dumbbells; in that case stabilize with a scull.
Abdominal Pike and Spine Extension. This is my favorite move for working the abdominals and erector spinae. Begin by tucking your feet under you. Then go into a pike, or a capital letter “L” position. Tuck again and extend both legs 45 degrees to the back. Try to keep the feet close together. Foam dumbbells held end to end on the surface of the water assist with stabilization; keep them on the surface of the water and let your abdominals do the work. This exercise can be performed without dumbbells; in that case stabilize with a scull.
Burpee: 1. Plank
2. Tuck
3. Drop the legs
4. Elevate
Burpees. This is a fun move! You need to use a noodle, preferably one of the denser more buoyant ones. Begin in a plank position. Tuck the feet under you and then drop the legs down to neutral, letting the noodle rise toward the surface. Push the noodle back down and flutter kick to lift the shoulders out of the water. Tuck your feet under you again and go back into a plank position.
Once you get comfortable in deep water you can really get a great workout. I enjoy the freedom of moving without my feet touching the floor. The late John Spannuth, the founder of the US Water Fitness Association, compared deep water exercise to flying. If you would like to know more about deep water exercise, check out my books. Water Fitness Lesson Plans and Choreography has lots of photographs and cues that tell you what muscles you are working. Water Fitness Progressions tells you how to progress your exercises from basic to high intensity interval training, plus lesson plans using various types of equipment.
Exercising in deep water has many of the same benefits as exercising in shallow water, plus a few more. The hydrostatic pressure in deep water pushes blood out to the extremities the same as in shallow water, but since more of the body is submerged cardiovascular efficiency is enhanced and the heart rate is even lower. Hydrostatic pressure against the chest makes inhaling more challenging, which strengthens the muscles of respiration. Ninety percent of the body works against the water’s resistance requiring increased energy expenditures during exercise, and improving muscular strength. Exercisers are able to achieve higher maximal contractions in the lower body and trunk compared to the same movements in shallow water or on land. Immersion in deep water completely offloads the joints leading to a greater range of motion and improving flexibility. There is an exhilarating feeling of weightlessness that comes with exercising in deep water.
Buoyancy creates a challenge to maintain neutral alignment. In shallow water, exercisers maintain alignment using their center of gravity located in the pelvic area, the same as they do on land. They receive feedback from the feet and ankles which allows them to adjust their form. In deep water, exercisers must achieve alignment between their center of gravity and their center of buoyancy, located mid-chest, with no information from their feet to tell them where they are in space. This can decrease body awareness, resulting in instability. A flotation belt attached to the body’s trunk can provide feedback, as well as engage the core muscles, and help the body maintain neutral alignment. Without neutral alignment, the body is at risk for injury. Exercising in neutral vertical alignment increases surface area which creates more resistance, allows exercisers to achieve more powerful movements, and burns more calories.
One of the best known forms of deep-water exercise is deep-water running, which has been studied extensively. The research shows that deep-water running helps prevent injury, improves balance, improves cardiorespiratory fitness, improves mobility, and reduces pain. Beyond running, deep-water exercise offers a variety of exercise options. Most exercises are done in the vertical position, but you can also use a diagonal tilt to the side, go side-lying, lean forward 45 degrees, get in a seated position or go into a pike position. Accelerating the arms and legs to center lifts the shoulders out of the water. Travel uses a variety of arm motions that require upper body strength. A number of exercises take advantage of the pool wall. There are not as many formats as with shallow water, but they include deep-water aerobics, high intensity interval training, circuit classes, and strength training. There are some kickboxing moves, Pilates exercises, and Yoga poses that can be done in deep water. The Arthritis Foundation suggests going to the deep end with a flotation belt if you have arthritis in the spine or shoulders. Ai Chi can be modified for deep water. See Ruth Sova’s book Ai Chi: The Water Way to Health & Healing, page 82, for my deep water modifications.
Noodles
Foam Dumbbells
Aqualogix Bells
Resistance tubing
Webbed Gloves
Hand-held equipment used in the deep end needs to float, otherwise it may sink to the bottom of the pool if the exerciser loses her grip. There are many types of equipment do float, including buoyant equipment such as noodles and foam dumbbells; drag equipment such as Aqualogix bells, and resistance tubing. Webbed gloves are worn on the hands and are not in danger of sinking. There are some great articles on deep water by Beth Scalone, MacKenzie Barr, Lori Sherlock, Whitney Kessie, and one by me on hand-held resistance equipment, in the December-February 2024 issue of Akwa magazine. Access Akwa on the members only section of the AEA website. There is also information on deep water, including lesson plans for cardio, intervals and strength training (with and without equipment) in my books Water Fitness Progressions and Water Fitness Lesson Plans and Choreography. I am a fan of deep water exercise!
Just getting in the pool lowers blood pressure for most people. The hydrostatic pressure of the water pushes blood out to the extremities, increasing stroke volume and cardiac output, while at the same time lowering the heart rate. Immersion offloads the joints, making movement more comfortable. When joints are submerged in water, they have a greater range of motion. Water also offers resistance, requiring the exerciser to apply more force to their movements. The resistance is in all directions, which promotes muscle balance. Since the water is a dynamic resistant force, the more force that is applied, the more resistance the water offers. Pool temperatures are typically 12-18 degrees cooler than body temperature, and water conducts heat away from the body, so exercisers remain cool and comfortable during exertion. Buoyancy creates a feeling of weightlessness, which is perceived as fun by most exercisers. All of these benefits apply no matter what exercise format you are using.
There is a misconception that exercise in water does not burn as many calories as exercise on land. Of course, the number of calories burned depends on many things including how hard the exerciser works, but given the same amount of effort, an exerciser will burn a comparable number of calories in water as on land, and sometimes even more. Dennis Dolny, Ph.D. reports his research on burning calories through water exercise in the Water Immersion Works guidebook, which can be downloaded on the PlayCore website. The Mayo Clinic also lists an estimated number of calories burned for various activities, and water aerobics compares favorably to other forms of exercise.
Water exercise is usually discounted as an acceptable form of exercise for people with osteoporosis because buoyancy reduces the impact compared to land based exercise. But research on water exercise and osteoporosis is ongoing and has found that shallow water exercise can slow the rate of bone loss and improve bone mineral density. Recommended exercises include jumping/rebounding, strength training and using power or force against the water’s resistance. In addition, the research has noted outcomes of improved strength, flexibility, balance and adherence. The best exercise is the one you can stick with! For more information, see Lori Sherlock’s article in AEA’s first quarter 2024 issue of Leader Tools.
Shallow water is the perfect place to work on balance. People who have fallen are often afraid of falling again and they limit balancing activities on land to minimize the risk of falling, further decreasing functionality. But in the pool, the hydrostatic pressure and buoyancy of the water is supportive, reducing the fear of falling. At the same time, water constantly moves, destabilizing movement and requiring multiple adjustments to maintain balance. Good exercises for improving balance are weight shifting, gait training, postural strength training, use of various foot positions, and one-legged movements. If there are muscle imbalances, these can also be addressed in the pool. For more information, check out the Water Exercise Coach blog post and video.
Finally, every type of equipment made for water fitness can be used in shallow water. That includes buoyant equipment such as noodles and foam dumbbells; drag equipment such as webbed gloves, Aqualogix bells, paddles and Aqua Ohm; resistance tubing; steps; drum sticks and more. There are options to please everyone. Shallow water exercise is definitely not just for little old ladies in shower caps!
Most of the time when we hear the word “core” we think of our abdominals. And in fact it is important to keep the abdominals and all the other muscles of the trunk strong. These muscles work together to maintain good posture and to support and move the shoulders, the back, and the hips. They are often referred to as the powerhouse of the body, stabilizing the trunk and allowing us to move our arms and legs powerfully and safely during exercise.
Beneath these core muscles are the muscles of the inner core and they have an important job to do. The brain is protected by the scull, the heart and lungs are protected by the rib cage, and the female reproductive organs are protected by the pelvic bone. But the remaining organs are protected by the inner core. The muscles of the inner core are the diaphragm at the top, the multifidus in the back, the transverse abdominis in the front, and the pelvic floor at the bottom.
Diaphragm. A weakness in the diaphragm can lead to reflux. Diaphragmatic breathing strengthens the diaphragm. To practice diaphragmatic breathing, sit comfortably in a chair with the shoulders relaxed. Place one hand on your chest and the other hand just below your rib cage. Breathe in slowly through your nose so that the stomach moves out against your hand while the hand on your chest remains as still as possible. To exhale, tighten your stomach muscles so that your stomach moves back in while the hand on your chest remains as still as possible. Another way to make sure you are breathing diaphragmatically is to put the tip of your tongue on the roof of your mouth just behind your front teeth. This stimulates your vagus nerve ending, which is involved in the regulation of breathing, and causes diaphragmatic breathing. Practice diaphragmatic breathing in the pool. Breathing against the resistance of the water by submerging the chest strengthens the muscles of respiration. Deep water exercise is great for this because the chest is continually submerged. If you are teaching a shallow water class, it is a good idea to include exercises in the neutral position (Level II) or suspended (Level III) so that participants’ chests will be submerged for part of the class. For more information on diaphragmatic breathing see the article from the Cleveland Clinic.
Multifidus. A weakness in the multifidus can lead to slipped discs. Some exercises to strengthen the multifidus are:
Bird dog. Get on your hands and knees, brace your core, lift one leg in back and the opposite arm in front.
Superman. Lie face down on a mat with your arms extended in front of you. Simultaneously lift your arms, chest and legs off the mat. Hold for a few seconds.
Side plank. Lie on your side with the elbow directly beneath your shoulder and your legs stacked. Lift your hips off the ground and hold for 20-30 seconds.
Another great way to strengthen the muscles of the back is to travel backwards in the pool. For more information on the multifidus see the article from Bret G. Ball, M.D., PhD. with Rose City Spine Surgery in Portland, Oregon.
Transverse abdominis. A weakness in the transverse abdominis can lead to a hernia. Some exercises to strengthen the transverse abdominis are:
Toe taps. Lie on your back with your arms to the side and knees bent in tabletop position (knees bent at a 90-degree angle and shins parallel to the ground). Keep your knees bent and lower one foot to tap the toes on the ground.
Bird dog. Get on your hands and knees, brace your core, lift one leg in back and the opposite arm in front.
Plank. Start in a pushup position with your elbows and forearms at your side and your palms facing down. Raise your torso off the ground and hold the position for as long as you can.
In the pool, you can do a plank holding a noodle or foam dumbbells with the hands directly below the shoulders. For more information on the transverse abdominis, see the article from Healthline.
Pelvic floor. A weakness in the pelvic floor can lead to incontinence. Women are more likely than men to suffer from incontinence. However, in men sometimes an enlarged prostate exerts pressure on the urinary tract, controlling the flow of urine, and the the pelvic floor becomes weak. If the prostate is surgically removed, men will have a more serious issue with incontinence. Therefore both men and women are encouraged to include pelvic floor exercises in their fitness routine. A good exercise to strengthen the pelvic floor is Kegels. To perform Kegels correctly, lift the pelvic floor and then gently draw in the transverse abdominis. There should be no change in your breathing, and your upper abdominals should remain relaxed. Perform the exercise gently and slowly. How long to hold the core contraction depends on the type of incontinence you are having a problem with (or wish to avoid). Stress incontinence is leaking when sneezing, coughing, etc. For this do 10 quick pelvic floor lifts 2 or 3 times a day. Urge incontinence is leaking on the way to the bathroom. For this do a maximum of 10 repetitions at a time, hold the contraction for 10 seconds at most, and take a 30-second break in between contractions. Kegels can be performed standing, sitting or lying down. You can include them in your water fitness class while standing or try sitting on a noodle like a bicycle. Cue to lift the pelvic floor off the noodle. My resource for this information comes from Marietta Mehanni, the pelvic floor ambassador in Australia, who presented a workshop entitled “Aquacise Your Pelvic Floor” in Dallas on October 5, 2019. Bridges and squats can also help strengthen the pelvic floor. For more information on pelvic floor exercises, see the article from Medical News Today. Some of my participants have thanked me for including them in my classes.
The hand is truly amazing! There are 27 bones in the hand. There are 15 muscles in the forearm that control the movements of the hands and fingers. We can turn the palms down and up, flex and extend the wrist, wave the wrist side to side, flex and extend the fingers, pull the fingers apart and bring them together, circle the thumb, and don’t forget the movement of the opposable thumb. Most of the things that we do with the hands require the strength of several muscles doing various movements simultaneously.
We probably think less often about our feet than we do about our hands, but the foot is amazing too. There are 26 bones in the foot. There are 29 muscles associated with the foot: 10 originate outside the foot but cross the ankle joint to act on the foot, and 19 muscles are inside the foot. All of these muscles work as a team. The ligaments in the ankle, which attach the bones together, contain receptors that give feedback to the brain about where the body is in space. We can dorsiflex the foot (pull the foot up toward the shin) and plantarflex the foot (point the toes). Inversion of the foot means rolling to the outside edge of the foot; eversion means rolling to the inside edge of the foot. We can lift the toes or curl the toes down. One of the most important things our feet do is transmit force both toward and away from the ground in weight bearing activities.
One thing we should do to take care of our hands is to wash them frequently. Plain soap and water washes away the viruses that cause the common cold, flu, COVID, and RSV. Remember to wash for 20 seconds, including between the fingers, the fingernails and the tops of the hands. Using hand cream will help prevent the skin from drying out. Some problems that may cause hand pain include arthritis, carpal tunnel syndrome, ganglion cysts, tendonitis, and trigger finger. For more information on these problems and treatments for them, check out the article on hands from John Hopkins Medicine. The pool is a great place to exercise the hands because the hands are constantly underwater, and therefore resisted. The Arthritis Foundation has a list of exercises for the wrists and fingers:
Hand and wrist wave – elbows are near the waist with the thumbs up, wave the hands side to side
Wrist stretch – the arms are near the surface of the water with palms together, then bring the hands toward the chest with fingertips pointing up.
Wrist rotation – circle the wrists
Finger curl – make a fist and extend the fingers
Cat’s claw – bend the fingers at the middle joint to simulate a cat’s claw
Piano – bend and straighten the fingers as if playing a piano
Finger flicks
Finger O – touch the thumb to the tip of each finger
Finger walk – slide one finger at a time toward the thumb
Finger spread – spread the fingers apart and move them back together
Finger lift – rest the palms on the thighs and lift the thumbs and then the fingers one at a time
Thumb bend – touch the thumb to the base of each finger
Thumb circles
You can also shake out the hands to release tension and help relax the muscles of the hands. Even though these exercises come from the Arthritis Foundation, they are beneficial to include in any water fitness class.
Some problems that may cause foot and ankle pain include heel spurs, corns, bunions, hammertoes, ankle sprains, fractures, planar fasciitis, Achilles tendon injuries and diabetes. For more information on these problems and treatments for them check out the article on feet from John Hopkins Medicine. Some exercises to do in the pool for the ankles and feet from the Arthritis Foundation are:
Point and flex the foot
Heel-toe lift – rock back on your heels then rise onto the toes
Ankle circles – or write your name with your foot
Ankle in/ankle out – roll the foot in to tap the big toe on the floor then roll it out to tap the little toe on the floor
Toe curl – lift the toes off the floor then curl the toes as if picking up a pencil
You can also walk on your toes and on your heels. Put one foot on the toes of the opposite foot and try to lift the the toes of the bottom foot.
Avoid gripping dumbbells with the wrists not in neutral. Avoid too much rebounding for the feet.
In addition to doing exercises for the hands and feet, there are some cautions for your water fitness class. Grip strength is important, but you want to be sure to relax the grip between sets with foam dumbbells. It’s a good idea to stretch the fingers or wiggle them or do one of the hand exercises above before beginning another set. Holding the dumbbells with the wrists extended can aggravate carpal tunnel syndrome. Be sure to keep the wrists in neutral, which avoids excessive strain and fatigue in the hands and wrists. To protect the feet, avoid excessive rebounding. When you tell your class to start jogging, they will automatically rebound. If you do not vary the impact forces, your class could easily rebound for 50 minutes. Include exercises in the neutral position with the hips and knees bent and the shoulders below the surface of the water (Level II), suspended exercises (Level III) and grounded exercises keeping one foot on the pool floor. When you do rebound, teach how to land. Landing toe-ball-heel will diffuse the shock. When landing toe-ball-heel, the heel barely makes contact with the pool floor before lifting off again, so do not cue to keep the heels down. Avoid repetitive impact on the ball of the foot because the metatarsal fat pad on the bottom of the foot frequently degenerates in women over 50. Offer modifications to jumping and rebounding for those who have plantar fasciitis. Aqua shoes are recommended because they can help protect the feet. Deep water exercise is best for anyone recovering from an ankle sprain.
Resource: Pauline Ivens, MS and Catherine Holder, PT, Do No Harm, 2011
You use both your hands and your feet constantly, so take good care of them. See you in the pool!
