Training With Power

Part of my training and racing plan for the upcoming Ironman Wisconsin 2007 will center on using a power meter. I'm hoping this tool will be extremely helpful in making my limited training sessions more productive and help me from going out too hard on the bike when the race comes around.

This morning, I put my triathlon bike on the Computrainer and did my first functional threshold power (FTP) test to try to get a feel for what my power benchmark might be. FTP is basically the amount power you can put out on the bicycle at the point where your muscles begin to produce more lactic acid than the bloodstream can flush (called "lactacte threshold, or LT), thus causing a build-up, which fatigues the muscle.

The higher your power output, the faster you go. Power at LT, or FTP, is used to determine your taining "power zones." By targeting workouts to specific power zones, you can train different physiological systems, and improve various aspects of your cycling. Knowing the exact power output in real time helps you focus on those power zones. For more information on training with power, check out CyclingPeaks Software, the gold standard in power training analysis software.

The FTP test I chose is advocated by Rich Strauss, an Ironman triathlon coach and owner of Crucible Fitness. Rich currently recommends a test protocol that requires a 15 minute warm-up followed by two all out 20-minute work intervals separated by a two-minute rest interval. The test should be performed on a flat course or trainer, and conditions should be as similar as possible each time the test is performed. The normalized power calculated from the 42 minute period encompassing the work and rest intervals is generally a good estimate of your FTP.

Here are my results:

Duration: 42 minutes (2x20' w/ 2' RI)
Work: 616 kJ
Normalized Power: 250 watts
Average Power: 245 watts
Maximum Power: 385 watts
Average Cadence: 95 rpm

So, my estimated FTP should be right about 250 watts. This leads to the following power training zones:

Active recovery:	less than 138 watts
Endurance:	140-188 watts
Tempo:	190-225 watts
Threshold:	228-263 watts
Aerobic Power:	265-300 watts
Anaerobic capacity:	more than 303 watts