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  • Cycling: Are you using a functional threshold power number that is too low?

    Cycling: Are you using a functional threshold power number that is too low?

    Cyclists that train with power meters are familiar with the various time trial protocols that determine threshold power or functional threshold power. What I want you to be keenly aware of is that you should do your time trial on the same type of course where you plan to do most of your intervals.

    If you do your threshold power time trial on a completely flat course, riding all-out for 20 minutes you will produce a certain power number. If you have access to a 20-minute steady climb and you do your time trial on that climb (given the same status of your body), I guarantee that your average power number will be higher for the same effort and average heart rate.

    This creates a problem if you are doing intervals based on power numbers. If you use your flat-lander power number to do threshold intervals on a climb, you won’t get the metabolic response you seek. The reverse is also true. If you use your hill-climber power number to do intervals on the flats, you won’t get the physical training you seek and the intervals will seem too difficult. 

    If you’re having a hard time understanding what I’m trying to explain, perhaps using running is a better example. Let’s say you can average a 7:00 pace per mile on a flat course, which is your threshold pace. If I ask you to do threshold intervals on a 10-percent incline at your flat-course pace, you would think I’ve lost it.

    The Hill Runner has a chart that estimates a 6:59 pace outside is equal to a 7:16 pace on an indoor treadmill set at 0-percent grade. Hike that grade up to 10-percent (keeping treadmill speed constant) and you are running a 5:26 pace per mile.

    Hills change everything.

    Back to cycling. For example, the set below will produce a lower average heart rate value on a hill than it will on a flat course:

    4 x 6 minutes at functional threshold power (2 minute complete recovery intervals)

    This set will produce a lower average power number on the flats than it will on a hill:

    4 x 6 minutes at lactate threshold heart rate (2 minute complete recovery intervals)

    What can you do to be sure you’re accomplishing the training affect you seek?

    One solution is to do two different time trials in a rested state, one on a flat course and one on a hill climb. Note the differences in power output and average heart rate.

    A second option is to use the values from one time trial and then use a blend of power, heart rate, rating of perceived exertion and common sense to achieve the training affect you seek.  The second option works only if you are experienced with your training metrics or have the help of an experienced coach.

     

     

     

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