There are many factors that go into an effective kick
Different groups have different attitudes toward kicking. Typical misguided mindsets include:
- Runners, cyclists, triathletes—“My legs are super strong; therefore, I should rely on them for most of my swimming propulsion.”
- Distance swimmers—“Kicking uses too much energy for a long race; I’m better off if my legs just stay out of the way.”
- Pull-set enthusiasts—“I’m far faster with a buoy between my legs; kicking is obviously counter-productive.”
- Victims of physics misconceptions (aka sinkin’ thinkin’)—“The water is trying to pull my legs to the bottom, so I need to kick bigger and harder!”
- Sadistic swim coaches—“Long sets of underwater dolphin kick are the only way to achieve the searing lung pain and insufferable leg-muscle agony needed to build true character.”
Well, OK—perhaps those coaches are onto something. But the truth is that many factors determine how effective your kick is.
- Every swimming motion involves the entire body; arm strokes and kicks are coupled together through the core. Every kick transfers energy from the core through the hips to the legs. Therefore, a propulsive kick requires strong support musculature in addition to powerful legs.
- Kicking too deep or wide can create enough drag to negate any propulsion gained. There is an optimum amplitude (range of motion) for an effective kick, and it’s probably not as big as you think.
- Greater ankle and hip flexibility enable more effective kicking.
- The percentage of energy allocated to the kick varies depending on stroke and distance. Sprinters use more energy on kick than distance swimmers, breaststrokers use more than freestylers, etc.
- Underwater kicking off the wall during a race is only useful while you’re kicking faster than you can swim on the surface. Depending on stamina and race distance, the optimum breakout point may change at different points in the race.
- Regardless of stroke, distance, or innate kicking ability, training to improve your kick provides more overall speed, better ability to execute bursts of acceleration to drop competitors, and better metabolism through enhanced leg-muscle blood flow.
The bottom line is that we each need to work on our kick if we want to achieve our full swimming potential.
Exercises for Efficiency
Kicking efficiency comes from moving your legs and feet through the right motions, which requires flexibility. Ankle stretches increase your ability to obtain maximum toe velocity at the end of the leg-whipping motion, as well as enabling pointed toes to minimize drag during gliding.
Kicking with fins can also enhance flexibility. As you kick, let the pressure of the water against the fin stretch your ankle.
Vertical kicking allows you to focus on sensing the water pressure against your feet. As you kick upright in place in deep water, notice the way the water feels against each surface of your foot (top, sole, sides) as you move through the full kick pathway. For flutter and dolphin kick, keep your toes pointed slightly inward, just inside your ankles (pigeon-toe position). Experiment to find the foot angles that provide the most thrust (lifting you higher in the water) and seek those same sensations when you return to kicking horizontally.
Fine tune your kick amplitude by kicking on your back. On flutter and dolphin, look for the “boiling water” turbulence right at the surface. You should see your thighs barely break the surface, but your knees shouldn’t come out of the water. For breaststroke kick on your back, the same idea applies: drop your heels toward the bottom during the recovery rather than pulling your knees upward and out of the water.
Get feedback from your coach to verify that your motion is efficient. Continue to include these drills in every practice until you’ve mastered the proper leg movements to generate thrust without excessive drag. And don’t forget the mental aspects of leg training; use positive self-talk to reinforce the idea that kicking is one of the advantageous tools in your arsenal of swimming weaponry.
Exercises for Power
To improve your kick, you have to practice kicking, and you must practice kicking hard. Viewing kick sets as rest periods between swim sets wastes a valuable opportunity for improvement. Just like swim sets, your weekly mix of kick sets should include all-out sprinting, short-interval high-efforts, and pounding out long distance kick sets. Approach kick sets focused on form, and remember your kick-set times as you would for your favorite swim repeat sets.
Build strength by kicking against resistance. Use a parachute, drag suit, or submerged kickboard on its end (AKA tombstones) to make you work harder for your yardage. Perform interval sets of kicking against a teammate or against a wall until you feel the burn in your legs. See how high you can lift your body during vertical kick sets and consider holding a weight to increase your workload.
Use fins only as the tools they were meant to be; don’t use them simply to go faster with less effort. In addition to enhancing ankle flexibility, using fins can increase maximum power by making your legs work harder. They can also help you fine-tune your stroke at race-pace swimming, enabling you to feel in advance the speed you’ll have in your tapered race at your goal meet.
Finally, consider cross-training. You can’t be in the pool all the time, but there are plenty of ways to strengthen your legs and core when you’re not in the water. I have found that cycling improves my swimming kick strength, but while running enhances cardio fitness, it doesn’t seem to translate to better kicking in the pool.
Avoid sitting all day. Get up and move around. Lunges, squats, planks, and toe-raises keep your legs limber and strong, and are easy to do throughout the day. By developing a kick-awareness mindset, you’ll find that your legs contribute more to your swimming than ever before!
- Technique and Training