Coaching a number of people that have come to swimming in their 20s, 30s and 40s leg kick can be a real issue. Generally in the pool you kick to keep your body flat in the water and avoid drag. Personally I also get my rhythm when swimming from my legs. However, for most their leg kick is almost counter-productive. Your legs represent massive muscle groups and consume a lot more Oxygen than your arms, providing 10-15% extra propulsion (if you have a great leg kick). Even with a great leg kick it’s questionable whether or not to kick hard during a swim. Over a sprint, yes. Over middle to long distance, probably not.
So do you stop concentrating on your leg kick. Absolutely not!
Whilst a good kick only improves a swim marginally, if at all. A bad kick can sap a swimmer of energy, prevent the body from rolling correctly (which in turn effects the pull and your reach), have a negative impact on your body position and create masses of drag. Incorporating leg kick into a swimming session also allows your upper body some recovery time whilst still working the lungs and core and notching up the k’s.
So where to go from here?
Firstly, to improve your leg kick you need to know whether there’s anything wrong with it. My suggestion would be to either get some professional coaching, or if you’re on a budget get a friend to film your leg kick during a session. Speak to the lifeguards before attempting any kind of filming in a public session! It might be possible to get some footage during quieter public sessions.
Secondly, websites like YouTube are a valuable resource. If you’re not sure on any topics watch some videos. Make sure you watch a few and get a general consensus. Just because someone has made a video (or written an article) doesn’t mean they know what they’re talking about.
Thirdly, if you’re only interest is open water swimming and you have a terrible leg kick and you pool swim in the winter purely to keep fit simply stick a pull-buoy in and forget about your legs. When you swim in salt water simply put your ankles together, don’t kick and let the salt water and your wetsuit do the work…it’s only going to create drag and use up Oxygen and energy, whilst potentially effecting your body position.
Your legs should rotate around with your body. This is where lots of people have issues. The maximum width your feet achieve should be consistent. Often when people breathe the distance between their feet increases (and they ‘scissor’). This creates lots of drag. Have a look at the link and see how the subjects leg rotate around with the rest of her body - https://www.youtube.com/watch?v=2hNRgzWXzFA
Runners tend to have stiff ankles and leg kick is all about flexible ankles and really ‘whipping’ those feet on the down stroke. Look up ankle stretches on the net and think about swim fins, to get a little more out of your ankle. It is still important however, to do part of the session without the fins.
To eliminate any rogue kicks or an increase in the distance between your feet, when you breathe for instance try this - https://www.youtube.com/watch?v=IEHdsb89yO0
Core – Any issues you have may not actually be created by your kick and may come about as the result of poor core strength or you simply not engaging with your core. Not using the core whilst freestyle swimming can lower the feet in the water, which in turn creates more drag and lifts the head position. For core drills try - https://www.youtube.com/watch?v=MY1kqFkKC60
You can also work on your core out of the pool - https://www.youtube.com/watch?v=yrz67cH_P8o
Try and kick with a straight leg. This isn’t achievable but that isn’t the point. You need to keep your legs as straight as possible.
Kick from the hip. Your Calf muscle can’t generate anywhere near as much power as your glutes, quads and hamstrings!
Just break the surface of the water with your heel. If you find yourself kicking air you’re simply wasting energy. If your heels aren’t breaking the surface of the water your feet are too deep in the water.
…and lastly, mix your leg kick drills up. If you’re not a great kicker don’t bury your head in the sand, do more leg kick not less!
To see how it’s done check out - https://www.youtube.com/watch?v=5CSFmJrLJLA