I often get asked about front crawl leg kick. Common questions are should I kick harder to go faster, how many times should I kick to every arm cycle or concerns that their kick is too gentle and isn’t doing anything. In this blog we’ll try to answer some of these questions.
The leg kick in front crawl only contributes a small amount to overall propulsion, maybe 10% for elite swimmers and less for the rest of us. So the first thing is most of us would benefit from spending most of our time and focus on the rest of our stroke.
Balance and Rotation
The main function of the leg kick is to help with balance and rotation. It helps to lift our legs and keep us horizontal in the water and to rotate effortlessly with the hips and shoulders connected.
We want the kick it to be as efficient and low energy as possible without causing any drag or wasted energy. This means kicking gently within the shadow of our body through a relatively small range of motion. Imagine swimming through a smarty tube. Triathletes will also want their legs to be fresh for the bike and the run.
The kick is described as a gentle flutter kick that is initiated from the glutes. Without this connection to the hips via the glutes the legs will be disconnected from the rest of the body, so it’s essential to feel this connection.
Common problems are kicking from the knee like kicking a football, or lifting the knee up like riding a bike. This type of action uses the big quad muscles which use a lot of energy and will also make your feet go outside of the smarty tube causing drag and wasting energy. This is extremely common amongst adults who have come to swimming from others sports such as football, cycling and running that are quad dominant.
Lots of kicking
Another common problem is the leg kick being slightly out of control and too hard. This is often a response to not feeling comfortable and balanced in the water. It is the brain’s way of making up for a lack of balance elsewhere in the stroke. If this is you then your priority is to keep working on balance and comfort in the water.
We never practice leg kick using a kick board or float. This is because the kick board puts your arms on the surface of the water making your legs sink. This is not the position use for front crawl and makes moving forward hard work. It can also encourage poor kick technique as you attempt to get your legs to kick to the surface by bending from the knee and get some propulsion. We practice kick technique in horizontal positions on the front and back and without a float (For TI Swimmers think Superman glide and Skate).
Lack of Propulsion
I also don’t go very fast, or very far when just practising my leg kick on its own. This is because I have very stiff and inflexible ankles, a stiff back, and lazy glutes from running and sitting. I practice in short sections (6-10 metres) focussing on good technique and connection to the hips, without worrying about how fast I go. When I swim full stroke my kick is efficient, low energy, does not cause drag. My kick actively helps me to rotate and connect through my hips, so that my swimming is a whole body stroke rather than relying on the weak shoulder muscles.
There are two types of kick. A 6-beat kick is 6 kicks per cycle. This is a traditional flutter kick that is most common. It is often what most people naturally start off with when they are learning their stroke and is also more common amongst swimmers that sprint or race shorter distances.
Two Beat Kick
A 2 beat kick is 2 kicks for every cycle (a cycle is 2 arms strokes counting both arms). This is a much slower kick speed making it use less energy and is particular beneficial for long distance swimmers and triathletes who want to save their legs for the bike and run. When you are learning your stroke start off with whichever type of kick comes naturally to you, and as your stroke develops it is well worth taking the time to learn both.
Benefits of a two beat kick
I find that the 2 beat kick helps me to connect to my hips and core and really makes me swim connected to my whole body, rather than just moving my arms and legs separately. Having both kick cycles in your repertoire will give you options depending on your speed and distance making you an accomplished swimmer.
More Tips on Learning to swim front crawl
- Is your front crawl out of puff?
- How to plan a swim technique session
- Five things to things to improve your swimming today
- Swimming drills
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