Recently we conducted a TI Coach training camp in Poznan Poland at the amazing Termy Maltanskie olympic pool and aqua park complex. (It will be the site of the 2014 European Championships, I believe). On the last day while doing some sync swimming and video in the 25m wide 5m deep diving pool I noticed the stainless steel vents crossing the floor of the pool, with bubble holes. I raised the question of why bubbles are pumped into a pool during platform diving competition. One of our trainees, a university sports ed graduate, explained that the bubbles help lower the surface pressure of the water to soften the impact of the diver in case of an off-vertical entry. This was new insight for me about diving, but it corresponded to what I already understood about hydrodynamics and the effect of bubbles on a swimmer.
Bubbles are evidence of turbulence. Bubbles mean there are voids in the water, which means there are low-pressure zones in that volume. Essentially, bubbles mean ‘low-traction’ zones. For a high diver this is good news. For a swimmer this is bad news.
A swimmer creating bubbles with each kick or stroke is the equivalent of a car spinning its wheels in the mud or snow. Bubbles mean there is less firm water to press against. In order to overcome the loss of traction when pulling air down with each kick and arm entry the swimmer has to exert even more effort to make up for it. Bubbles are the product of in-accurate movement patterns and lead to considerable unnecessary waste of energy.
Consider these three swimmers in the photo:
Which one is getting the best traction in the water?
Erroneous thinking has crept in and built a loyal following the culture of swimming for a long time. It is commonly believed that the sound of waves and splash and slapping of feet and hands on water was a sign of good hard work and improving swimmers. It may be hard work, but not necessarily good work. In fact that noise, that splash, those waves, those bubbles are all evidence of wasted energy – inefficiencies being perfected over thousands of meters.
A pool full of hydrodynamically astute swimmers, even at peak effort level, would be shockingly quiet and calm.
It is impossible to remove turbulence completely, and as velocity increases so will unavoidable turbulence. (Humans have too many un-fish-like moving parts!) However, a massive proportion of the turbulence a common swimmer makes is quite unnecessary if only she trains carefully to reduce it. It does not require a down-grade in her effort, just an upgrade in her accuracy of movement. It is essential for the aspiring swimmer to make turbulence-removal, drag-removal, bubble-removal a top priority, even over power production.
Why produce more power, more waste when you can get the job done with less? You can still swim fast, but do it quietly. In fact, the quietest swimmers will be the few who pass the rest and reach the very top of their event.
Eat My Bubbles: It’s a clever (and popular) boast among swimmers, but scientifically-speaking it is not something to brag about. If you can see enough of my bubbles to eat them then that means I am wasting a lot of energy in front of you. Actually, that may be a good sign to you that your quiet, efficient stroke will over take me soon.
I was paid a nice compliment last fall in the sea as we were practicing drafting and pace-lining in a group swim. One swimmer came up after a set and said he liked the experience but had a hard time swimming behind me because he couldn’t find my bubbles to follow. Indeed, I make very, very few. Not only is it a sign of low turbulence, it is also a great way to stay ‘hidden’ in a racing pack of swimmers.
So what can you do?
It’s actually quit a simple idea. While you swim spend a great deal of time concentrating on: no splash, no waves, no noise, no bubbles. Even at top effort levels.
Don’t worry, you may not be good at it yet because you haven’t practiced it (you have to start at slow speeds and work your way up). It’s simply a new skill to learn. But you’ll soon discover the effortless speed that comes from obsessive drag/wave/bubble removal. And then no one following you – and falling behind you – will be able to find any of your bubbles to eat.