Thursday, January 02, 2014

Like It Or Not, You Can't Avoid The Yellow Zone

A few weeks ago we were down at our local Ironman event in Busselton supporting many of our squad athletes competing in the race. Western Australia is famous for its beautiful beaches and water quality, and this year the competitors were greeted on race morning with some fantastically flat conditions. The Indian Ocean looked like a swimming pool with just a very light breeze over the surface:

Dream race conditions? Strangely, many of race competitors said after the race 'Hmmm, it didn't seem that flat out there!'. So what happened?

Take a look at the start, this is about 200m into the 3.8km race:

(expand any of the images in this post by clicking on them)
You can see the complete flat water out ahead of the swimmers but unless you are leading the field, absolutely everyone else is swimming in choppy water, even if they are trying to find a bit of free space for themselves.

We're going to talk about two zones in there, the first (call it the red zone) is where swimmers are closely bunched, as their wake and splash combines, it creates a very intense turbulence. This is the 'washing machine' effect many triathletes talk about:

The second zone (call it yellow) is a lower level - but still significant - zone of choppy water created in the larger gaps between swimmers. Swimming in this zone the water will still feel choppy, much more so than in a swimming pool.

Highlighting those zones on the original start image above:

The interesting thing about the yellow zone is how quickly it forms and widens out hundreds of meters wider than the field itself. Notice how the swimmers nearest the camera are swimming in a light chop despite being at least 100m wide of the main field:

The yellow zone is extending right out, hundreds of meters to each side of the main field. Remember the wider ocean is near perfectly flat, this is all being created by the swimmers:

The same thing is true towards the end of the race where the field has spread out. Here's the last 100m of the swim course before the swimmers arrive, looking beautifully flat:

Once the pros have been through and some of the top age groupers, the yellow zone is already well developed and creating much rougher water for these guys (taking around 60 minutes for the 3.8km):

If you look at the expanded image you can see the chop of the yellow zone gradually fade away towards the horizon.

So what can we conclude? Very simply, you can't avoid disturbed open water during an open water triathlon or swim. Even if you are racing in a perfectly flat lake and try and swim off to the side, the water will quickly become much rougher than you experience in the pool.

For this reason it's essential that you develop a stroke style that is robust enough to handle these conditions. 
If you've worked on trying to make your stroke as long as possible and added a pause-and-glide into your stroke timing then you'll be decelerated in the gap between strokes from the constant buffeting of all those small wavelets.

On the flip side, a stroke with some purpose and rhythm is going to be a real advantage to you, helping you punch through the chop, which is why nearly all elite open water swimmers and triathletes use this stroke style. Even a small lift in your stroke rate (say by 3-5 strokes per minute) will make a huge difference to your performance.

And the red zone? Well that's the place where you're going to get swept to a fast time drafting off other swimmers, so really you should be aiming to be in there mixing it up if you want to swim to your ultimate potential! It's not that hard to swim well in the red zone but practise and confidence will make a huge difference, which is why you should be practising your open water skills on a regular basis, even during the winter with a group in the pool.

Happy New Year and Swim Smooth!

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