Many swimmers spend a lot of time working on their hand and arm movements during the front crawl stroke cycle, but often forget what is happening with their legs. The leg kick is frequently ignored because athletes want to save energy for the bike and run. In reality a good leg kick is important to help with a good body position and aid with a continuous drive in the water. Dan Bullock looks at the importance of a good leg kick.
Effective swimming is one of the most biomechanically difficult sports to measure in terms of recognising and calculating what is happening when it is done well. Elite swimmers can hit the same number of strokes length after length but there will be subtle variations in terms of the pathways each arm revolution takes. The more stable the foundation that these movements are based upon lead to more similar movements being repeated. Having recently spent two weeks with over 50 swimmers and triathletes on several training camps I noticed several key patterns developing. Issues with stroke stability and key inaccuracies were apparent time and time again as we worked with adults improving their front crawl. It was rewarding to see some significant breakthroughs in terms of getting faster after performing just a few key drills. I have relied on these ‘basics’ for many years now and while quite simple in their appearance there is a lot to them. I was pleased, but not surprised, when I also finally found footage of some Olympians doing them in their recovery swims at a U.S. University.
Developing A Good Leg Kick
It is imperative to change your approach to swim technique in order to break through to more economical swimming. Working from the legs up may seem strange but I see them causing most issues as I teach on a daily basis. Improving your leg kick is possibly the single biggest breakthrough you can make to your front crawl stroke. Personally I would take a perfect leg kick with a less then perfect front crawl arm pull over a bad kick and a perfect pull/catch position any day. With a good leg kick the act of swimming should be less tiring.
A wetsuit will not cure a bad leg kick and continually pulling will not help the issues that are slowing your full stroke front crawl. Adding fins will generally make a bad leg kick faster, but it won’t stop it from tiring you out Wearing a band will reduce a bad kick but not teach you what a good leg kick is. The kick should not be engaged to the point that it is majorly propulsive. We need the kick to hold the body in position and to help initiate rotation. It is not about propulsion. For quite some time now I have championed the need for a better front crawl leg kick to swim faster. Some might argue that good leg kick will tire you for the bike and run, but a good front crawl leg kick should not tax your leg muscles that much. How else are you going to get faster? You are not going to get much taller as n adult, your feet are not likely to grow and your arms are also going to remain as they are, so our ‘levers’ are set.
It’s important to avoid the kick being too big where kicking outside of the profile of the body creates drag. The disparity between how you imagine you kick and the steeplechase type hurdle efforts I regularly see is huge. When people see their video playback they are amazed to see the scale of the kick, when I instruct on just how small a good kick athletes cannot believe how little this really is. It is easy to see how this happens because on dry land strong leg movements do create speed. The bigger and faster movements usually dictate a large return. The skill when it comes to swimming is limiting the range of movement
Your leg kick, even while mechanically accurate in terms of a relatively straight movement from the hip, can still be quite big. If you think of the leg kick as a pendulum then it is easy to see how a small movement at the hip can generate such large unwanted positions down at the feet It is sensible to start practising the plank position in your daily routine, along with the Pilates ‘swimmer’ movement to supplement and accelerate the small kick control. Adding core exercises like these help with posture, reduce the risk of injury and can help with holding a better aero position on the bike. A strong core will help with controlling the leg kick and help keep it small. Also remember to mobilise the ankles so the feet can turn inward and improve ‘usable surface area’.
Feel the big toes tapping as a constant reminder of this aspect of the kick. This will also stop the feet splaying too far apart if you maintain a fast rhythm.
If all the above falls into place and your kick mechanics improve, then the kick will add traction to the stroke, rather then propulsion. You will then stand a better chance of creating rotation around the long axis internally. What I mean by this is that if the legs, core and hips generate the ability to get the upper body rotated then it becomes sustainable and symmetrical. The movement gets repeated over and over again. Often the breathing leads and promotes your rotation as the head lifts aggressively, and by deduction you can assume you are not rotating when you are not breathing. Ideally we look to create the front crawl body positions without the arms involved and so it continually happens regardless of whether you are breathing or not the torpedo drill is perfect to help with this.
In the torpedo position the legs are kicking, the hips rotating and the core is involved in lifting the shoulders and getting the upper body partially onto its side. The kick needs to do this so that rotation is delivered equally and continuously. If the head is lifting while breathing during full stroke this drives your rotation. This often results in the need for a wide push down of the arm to help prop the head up. To stop this wide sweep of the arm from unbalancing you it often needs a wide leg kick to counterbalance. With each breath there is a massive drop in speed due to the increase in surface area to your profile.
Once the shoulders start to lift above the surface from practicing the drill without the arms involved you stand a chance of making bilateral breathing a lot easier within your full stroke. The shoulders are no longer in the way because they remain low as you attempt to breathe. As the shoulders lift, the elbow is then taken higher and so the trajectory of the hands can be improved. Without rotation the shoulders are lower in the water. As a result the elbows are kept lower as the arms recover, and swing the arms low and wide creating further imbalances.
Internal rotation means the lifting and rotating continues even when you are not breathing. If the rotation originates externally from an aggressive breathing movement, with the lead arm pushing down and so not catching, coupled with the head lifting into the breath, you will forever be swimming practically one armed and running the risk of injury as the shoulder takes a lot of the pressure. The role of the extension position will help you hold the arm outstretched and learn to breathe off the outstretched arm without it falling away because it supports the head when breathing. If the torpedo position promotes the rotation to come from within, then the extension position is the drill that teaches you just what is enough leg kick to hold you on your side.
If the leg kick is under control and stabilises then you should be able to hold the surface shoulder stable in this position. If the kick is out of control then it will be reflected in vigorous movements in the surface shoulder. This extension can be help by practising the superman drill.