Most Common Swimming Mistakes - The Weak Leg Kick

As mentioned in an earlier post, a weak leg kick  is one of the most common swimming mistakes swimmers make, this is so whether you are swimming in a pool or in open water.  Often it is said, especially in open water swimming, that the kick is not that important.  Yes, this may be true if you are relying on your kick solely for propulsion, however, the kick is not used only for propulsion.  The kick affects your body position, drag, rotation, and energy use. And a good kick should keep your legs high keeping your body in a good position, it should lower your drag and drive your rotation and most importantly minimise your energy expenditure.

A good leg kick requires: you to kick from your hip flexors; ankle flexibility; kicking with pointed toes; good timing. 

Tips to Improve a Weak Kick

Sources:  Go Swim and Swim Smooth

i)  Kick from your hip with relatively straight legs - don't kick from your knees.  In other words don't bend your knees too much when kicking.  Dryland flutter kick excercises are great for strengthening your hip flexors:  Lie on your back, with your hands under your butt cheeks for support. Lift your head and shoulders off the ground, look down towards your feet. Lift your legs 5 to 7 inches off the ground, point your toes and flutter kick (just like freestyle kick in the pool). Time this exercise, between 30 and 60 seconds X 2 sets.  
This is a great clip from Go Swim explaining the Straighter Leg Flutter Kick

ii)  Ankle Flexibility - this is one of the most important keys to an effective kick.  Here is a  basic ankle exercise.  Sit on the floor with your legs stretched out in front of you slightly apart.  Point your feet as far as possible towards the floor trying to touch the floor, hold for a few seconds, then flex your foot and try to point your toes back towards your body. Repeat 10 times.   Now, make circles inwards with your feet do this 10 times, then make circles outwards do this 10 times. Remember to do this slowly and feel the stretch.  For the best results do a little everyday.

ii) Always point your toes when swimming - not pointing will slow you down!  This should be a gentle point and your calf muscles should stay relaxed. Source:  Swim Smooth

iii)  Timing -  The kick should be timed with your hand entry, in other words, as your one hand enters at the front of the stroke the opposite leg should give a kick. Swim Smooth suggests that this usually comes naturally to most swimmers, so not much time should be wasted thinking about this one unless you struggle with it.  I tend to agree, I'd rather focus my energy on something else.