Friday, January 11, 2013

Becoming A Diesel Engine!

When training for any swimming event you need to make sure the work you are doing in the pool is the right sort of training for the distance you are racing. If you are a triathlete, open water swimmer or pool-based distance swimmer, this means training your ability to hold a strong pace for a long time. At Swim Smooth we call this "becoming a diesel engine".

If you come from a gym or team sport background then you are likely to be quite fast twitch and anaerobic. You might hold a very fast pace for 50, 100 or 200m but then quickly drop off over longer distances. This is akin to a high revving petrol engine, which is great if you are racing over those shorter distances but far from ideal for 800, 1500 or 3800m events.

Your genetics can bias you naturally towards distance events or shorter sprints but with the right sort of training you can shift your fitness in the direction you want to go and for most swimmers reading this blog, that means training to become more of a diesel engine. We'd all love to have the best of both worlds and be great sprinters and great distance swimmers too but that's not possible, otherwise the best sprinters in the world would also win the gold medals over distance events.

Going Diesel

We recommend CSS training as the mainstay of your fitness training to develop that diesel engine and become a great distance swimmer. You can find out more about training using CSS here, in our book (chapters 24 to 27) and follow CSS sessions in our waterproof training plans.

Even if you consider yourself quite a slow swimmer this sort of training will be very beneficial to you as it's likely your diesel engine is underdeveloped and improving it is one of the keys to you becoming faster and feeling more relaxed in the water.

When performing CSS sessions always bear in mind that pacing things out well is critical. If you start fast and then blow-up you're just training the petrol engine again!

Aim For Less Than 4% Drop-Off

To check the drop off in your pace as distances get longer you can use the 200m and 400m timetrials from the CSS test. If you have a large drop off in speed during the 400m versus the 200m then this trend will continue and over longer races you'll be much slower again.

A good rule of thumb to see how diesel you are becoming is to aim for a drop off of 4% or less in speed between the 200m and 400m timetrials. Here's two examples:
Rory proudly wears our Diesel Swimming
Engine shirt after swimming the
19.7km Rottnest Channel Swim

- If you swim 8:10 for 400m and 3:50 for 200m, you slowed down by 6.5% over the 400m. This says you've got a lot to gain from CSS type training and it should be a real priority to improve your swimming.

- If you swim 6:00 for 400m and 2:55 for 200m, you slowed down by 3% over the 400m. CSS training is still important to you but your diesel engine is coming on nicely - well done!

If you can reduce that drop-off then you're almost guaranteed to be improve your CSS pace and be quicker over any distance swimming event.

We created a quick calculator here to save you doing the maths yourself, if this proves popular we'll integrate it into our site:

Quick tips on performing the 200m and 400m timetrials:

- Do the 400m first, it will affect the 200m less than the other way around.

- Make sure you pace them out well, if you have a friend or coach to help then ask them to take your splits every 50m to check your pacing.

- Don't use your PBs, test your current fitness and swim each as fast as you can. :)

Swim Smooth!


Anonymous said...

Just worked my 'drop off' at 3.8%.
Have been loking for a way to compare my pace at other distances e.g. at 50m up to 2500m. Would you suggest 4% difference in speed is a fair assesment each time the distance doubles?


Odannyboy said...

Nice calculator. I suprised myself with a 2.6% drop off, which is heartening and hopefully shows the work I'm doing is pulling me in the right direction.

I'd be interested also in suggested drop offs across the longer distances (similar to the example of Pauls channel swim used in the SS book p175)

Adam Young said...

Hi John and Odannyboy,

We like to use the calculated CSS pace as the reference and then from there you might get:

400m : CSS pace -2 to -4 sec per 100m

1500m : CSS pace

5km : CSS pace + 2 to 4 sec per 100m

10km : CSS pace + 6 to 10 sec per 100m

Hope that helps! (from page 178 of the book)


Anonymous said...

Is it possible to guesstimate CSS by perceived effort? For someone who doesn't have the sophistication of a stopwatch! I use perceived effort in my running training to do replications at just under race pace. Maybe CSS would be something like 7/10 effort?

Adam Young said...

Hi Anonymous,

Yes, with experience it is. The key thing is pace judgement which is harder to develop for swimming than running but otherwise you should be able to get it just like running.

Does your pool not have a pace clock? You're going to find it difficult with any reference. I tempo trainer pro is highly recommended to help develop this.


Wyatt said...

What kind of rest or work should you do in between each test? I tried it out last night and had a 3.7% drop. I had about 7 minutes in between tests with just 50m of light kicking and 50m of light breast stroke. I definetely didn't feel as fresh on the 200m piece.

Adam Young said...

Hi Wyatt,

That sounds about right, approx 10 minutes of light swimming and recovery.

For sure you won't feel fresh during the 200m but that shouldn't affect your performance too much - many swimmers do PBs at the end of swim sets after all. So much of fatigue is in the mind!

Cheers, Adam

Peter Barnes said...

Hi, when using a wetronome to do CSS training I have it set to 32sec per length but don't want/have time to re-set it at the end of each set which means that my rest interval also has to be 32sec - any thoughts?

Adam Young said...

Hi Peter,

Yes, that's right - unfortunately you're a bit stuck with that with a Wetronome. The Tempo Trainer Pro has a solution as it has a reset button on it, which resets the timer straight away and immediately sets you off on another beep.

Have you tried setting it to beep every 16 seconds? It'll give you a beep half way down the pool (if you have a reference marker there it's useful in itself) and also halve your rest interval.



Peter Barnes said...

Thanks Adam, such a simple solution it's almost genius. Cheers, Peter

Eric Peters said...

Could you share the formula for the calculator?

Adam Young said...

Hi Eric,

For each distance, divide the distance in meters by the time in seconds work out the speed in m/s.

Then calculate the percentage difference e.g.

Hope that helps!


Anonymous said...

We want to see a 4%, or less, drop off in speed between the 200 and the 400, right?

What about the longer distances? How should one's speed hold up between the 400 to 800 and the 800 to 1500?

Ultimate question - how does/should a 1500m time (24:00 say) convert to 800 or 400?



Anonymous said...

Sorry Adam, you've already answered my question in a previous comment


Nicolas said...


Do you have scientific references that suggest a 4% drop off is optimal?

Adam Young said...

Hi Nicolas,

We can do better than that, when you test the best distance swimmers in the world, they all have drop-offs less than 4%. Really this has to be the case otherwise the best sprinters and middle-distance swimmers would also be the best distance swimmers (and vice versa) but that simply isn't the case.



Helen said...

I've a 1.1% so pleased :-)
But I have a question about my tempo trainer, my CSS is currently 29secs, but I feel like I have become confident at this speed and want to start pushing it down a little, but 28 seconds is just a little too fast! It is ok for 100m, and 200m sets, but not 400m. Is there a way of using my tempo trainer to do say 28.5? My setting 2, only seems to have whole seconds as a choice?

Adam Young said...

Hi Helen,

Yes if you put it in mode 1 you should be able to slow it right down and set it to 28.50 - that's how we do it!



Helen said...

Brilliant, thank you, I knew there must be a way!