The Art of the 20 Minute Field Test

If you train using a power meter, you have probably performed a field test to set your power training zones. Most coaches recommend a 20’ Field Test to do this. Once you have your average power for 20’, you plug this number into one of the various calculation methods out there and the result is your new set of power training zones. 

A well-paced 20' Field Test looks something like this

The 20’ Field Test is a big deal because if you blow it, the resulting training zones will be inaccurate…and it’s easy to blow it.  You are probably thinking, “How hard could it be to ride hard for 20’?”  You can go out too hard, you can go lose concentration and fall off the pace, or you can simply not push yourself hard enough.  The goal is to squeak every last watt out of your body during those 20’.

Over the past few years, I have done many of these 20’ tests and I actually get nervous before them. I know I am a dork.  As a 40+ endurance mountain bike racer with very little genetic talent, my biggest adversary is myself.  I try to beat my previous 20’ Field Test each and every time.  

Here are my tips for executing a successful 20’ Field Test:

The Day Before

• This is not a good day to jump into the local World Championships ride.  Take it easy.
• Choose your route.  In a perfect world, you will test on the same stretch of road each time.  
• Ideally this will be a gradual (4 – 6 %) grade.
• Check your bike.  Is the bike you plan to ride ready to rock?
• Eat & Drink sensibly.  This is not a good night to drink three or four beers…unless you are “The” Dave Saurman and then that would be considered taking it easy.
• Laundry.  Is your favorite bike kit clean?  Yes, the the 20’ Field Test is worthy of wearing your favorite bike kit.
• Charge your Garmin/Joule/SRM or whatever bike computer you plan to use.  How bad would it suck to have your Garmin die 16.3 minutes into your 20’ Field Test?  It would really suck...especially if you were killing it!

Field Test Day

• Eat your normal “pre-race” breakfast and drink your normal amount of coffee if you plan to do this test in the morning.
• Poop.  I cannot overstate the importance of this step.
• Put on your favorite kit and use a healthy dose of chamois creme. You might as well look fabulous AND be comfortable while turning yourself inside out.
• Important items not to forget:  Two water bottles, your Garmin/Joule/SRM, and your iPod.
• Check the PSI in your tires.
• Roll out.

The Test

• A good warm-up is very important and you want to start the test with a good sweat going.  Try to get a solid 30-40’ warm-up in on your ride to your chosen testing location.
• Focus.  Take a moment and wrap your brain around what you are about to do.
• Pee one more time.
• Get fired up!  I like to visualize that I am climbing Teton Pass with my stone-cold homie, Fiddee Cent, and I launch an attack so violent and shocking that he is forced to pull over and sit down on the side of the road to contemplate his life as a cyclist.  Bam!
• Turn the volume on your iPod up just a fuzz louder than normal.
• Place your finger on the LAP button of your computer, and…Go! 
• Start smart.  If your last test produced a 300 watt average for 20’, don’t leap out of the saddle and throw down 500 watts for the first two minutes…your test will end badly.  I know this much.
• 5 Minutes In:  Your HR has skyrocketed and you’re breathing really, really hard already.  This alarms you a little.
• Focus.  Keep the pedals turning over and stay seated.
• Stop watching your HR.  It doesn't fucking matter at this point.
• 10 Minutes In:  You have already thought about quitting.  You might be looking for little pieces of glass to run over so that you can honestly say that you flatted and couldn't finish.
• Keep staring at the watts on your computer and WILL that number to stay at or above your target.
• 15 Minutes In:  You can feel your heartbeat in your molars.  You are 100% mouth-breathing now and probably drooling a little bit.  This is good.
• Grunting at this point is perfectly acceptable.
• You have no more thoughts of quitting because the thought of having to do this all over again is far more horrible.
• Your upper body is pumping like a Texas oil rig as you squeeze every muscle in your body in an effort to go faster.
• 18 Minutes In:  This is too soon to “empty the tank” because you are running on fumes. Stay steady.
• 19 Minutes In:   Drop one cog, stand up, and give it everything you have for the last 60 seconds. (which will last longer than you could ever imagine)
• 19:59…and…hit the LAP button.
• Try to keep rolling and stay on your bike as normal vision returns.
• Congratulations!  You have just achieved a new PR for a 20’ Field Test.

As a result of your new PR, your training zones will get adjusted upwards and every interval you do moving forward will now be harder.  Ooofta!