Thursday, October 3, 2013

Fatigue Profiling

By Hunter Allen, PCG Founder/CEO and Master Coach

Peaks Coaching Group Fatigue Profiling

One of the most valuable uses of a power meter is determining your strengths and weaknesses. To this end, Dr. Andrew Coggan and I created a table called the power profile that allows you to compare your bests to those of your peers.

The power profile is a great tool for determining your strengths and weaknesses, but it doesn’t tell you the whole story.
For example, take Robbie McEwen, who was what we would call a pure sprinter. In order for Robbie to win a race, he had to pop out of the draft with not much more than 100 meters to the finish in order to use his blisteringly quick acceleration to win. If he tried to win the race by starting the sprint too early and “drag racing” other sprinters to the line, he almost always got beaten.

On the other hand, take Alessandro Petacchi. The sprints he usually wins are the much longer sprints in which he does “drag race” other sprinters to the finish line from 300 meters out (or more). If Petacchi waits too long and allows the sprint to start from only 100 meters out, he doesn’t have the snap that Robbie does, and he gets beaten.

Both of these riders are great sprinters and have won stages in the Tour de France and the Giro D’ Italia. There’s no question about their abilities as great sprinters, but each of them has to win a little differently. What’s the difference, you ask? Well, it comes down to their specific fatigue resistance within their neuromuscular power system or, in other words, how quickly they fatigue in an effort lasting from 5 to 20 seconds long.

Why is this important? Knowing what type of sprinter you are might have a profound impact on your training plan and could also impact your racing strategy and tactics. To help you understand a little more about your fatigue resistance, we came up with the fatigue profile, which can tell you exactly which of your strengths are really strengths and which of your weaknesses are really weaknesses.

Your fatigue profile doesn’t pertain just to your sprint; it pertains to all your power training levels from Level 4 to Level 7. In this article we’ll focus on Level 7 (neuromuscular/sprint power) to get you started determining your fatigue resistance. Unfortunately, the first step is to do some testing. If you’ve been training with a power meter for a while, you may already have the necessary data and just need to mine it. When we consider Level 7 power for the power profile test, we’re looking at not only just the best 5 seconds but also your peak 10 seconds and peak 20 seconds.

Let’s first start off with the testing. I recommend you test only one or two specific systems on one day and then, depending on your fitness, either rest for at least two days before doing the next two systems or do the next test the very next day. Start out with Level 7 and/or 6 first, so that you can get in the harder, shorter, more intense efforts in when you’re freshest. 

Fatigue profiling testing protocol:

Test of Level 7: Neuromuscular Power

1.  Warm up for 20 minutes, taking it easy and not overdoing it. Keep your watts under 75% of your FTP, or solidly in level 2 endurance pace.
Start out with 3 small ring sprints from a slow speed of 8-10 mph on a flat to very gently (3% or less) upward sloping road. I suggest a gearing near to 39x16 and a short sprint of 50-75 meters. 

2.  Rest for 2-3 minutes between each.

3.  Now do 3 sprints in the big ring. The first sprint is 150 meters long, starting at 18 mph and using a gear of 53x17 (50x16 if you have a compact). There are no shifting restrictions in any of these sprints, so shift as much as you need to, but I suggest trying to wind out each gear sufficiently before shifting to the next harder one. The second sprint is 250 meters long and starts at 20 mph using a gearing of 53x15 (50x14 for compact). The third and final sprint is 300-350 meters long, starting at 24 mph and using a 53x14 (50x13 for compact). Rest for at least 5 minutes between each sprint.

4.  Ride for 15 minutes at endurance pace (Level 2, 56-75% of FTP).

5.  Finish the ride with 30 minutes of Level 2, riding at 56-75% of your FTP.

Now that you’ve tested three very specific time periods in order to tell us more about your profile, let’s get the data out of your power meter and figure out your best wattage for 5 seconds, 10 seconds, and 20 seconds. Put that information into the chart below to figure out your fatigue profile for Level 7. I’ve also created a small online widget for this, and you can find it at

The fatigue profile is broken down into five categories relative to your fatigue resistance. The first two categories are called “well below average” and “below average,” meaning you have below-average fatigue resistance in the shortest time period in the tested range. Well-below- and below-average resistance, or “very high explosiveness,” means that the shortest time period in each level tested has a very high wattage, but there is a quick and large percentage drop-off of wattage in the longest time period in the range (like Robbie McEwen).

The “average” category is defined by having an average fatigue resistance in the first time period tested and then degrading at a linear rate to the longest time period. For example, let’s say that while testing your neuromuscular power, you do 1200 watts for 5 seconds, 900 watts for 10 seconds, and only 700 watts by 30 seconds.

The last two categories, “above average” and “well above average” fatigue resistance, include riders who might not have the highest wattage in the shortest time period but whose watts do not degrade very much over the entire range of the test. For example, a rider with above average fatigue resistance might not have the greatest pure sprint but could very well excel in a longer, uphill sprint where fatigue resistance is more important. There have been many non-sprinters who have won longer uphill sprints because of this very fact. A rider categorized as above average might barely be able to crack out 1000 watts for 5 seconds but still has 880 watts at 10 seconds and at 20 seconds is maintaining 850 watts, hence his tremendous fatigue resistance.

How does this knowledge help you? Let’s say your power profile is the “sprinter” profile (downward sloping to the right), but every time you initiate the sprint from 300 meters out, you get beaten on the line with riders slowly closing the distance as you fatigue within the last 50 meters. “But I’m a sprinter!” you say. “How come these guys beat me in these longer sprints?” This would be an example of a sprinter with below average fatigue resistance, someone with an incredible snap who can beat the pants off anyone in a short 100 meter sprint but lacks endurance when it comes to a longer sprint. This might be trainable or it might not, but one thing is for sure: if you’re going to win the race, you need to make sure to wait until the last 100 meters before you hit the front. This is exactly the type of sprinter that Robbie McEwen was. Every time there was a long sprint and he had to drag race a sprinter with “average” or “above average” fatigue resistance like Alessandro Petacchi, he lost. If you’ve watched the sprints McEwen won, you know that they all were when he was able to pop out of the line with 100 meters to go and then unleash his incredible five-second burst of power.

Fatigue profiling compares power within ranges of durations taken to be representative of the same physiological abilities, to gain insight into a rider’s relative strength and weaknesses and to understand how well he can resist different form of fatigue. You might find that you don’t fit perfectly in one category or another. You might find that while you have category 3 stamped on your racing license, your anaerobic capacity might be as good as a category 1 rider’s. Use your best judgment. Crossing categories often indicates an area in which improvement can be made.
For more information on fatigue profiling, order yourself a copy of the second edition of Training and Racing with a Power Meter, in which Dr. Coggan and I discuss the concept in further detail.