Testing: Anaerobic vs. Aerobic & Fatigue Resistance

Before diving into another season of training on the bike, or jumping into serious training for the first time, it helps to know a few things about your current fitness as you get started. Testing on the bike has become common place for structured training. We’ll focus on the specifics of our Waite Endurance Testing Method here; but most testing protocols are intended to answer questions like these…

• Where is my fitness at right now? Identify a baseline from which you plan to improve.

• What are the best ways to spend my training time? In order to maximize your improvement.

• What effort levels should you should be training at? Set your training zones.

There’s More to Power than Just FTP.

For many years, a rider’s FTP (Functional Threshold Power) has been the focal point of where a rider’s fitness. Percentages of FTP is also how many riders set their training zones. FTP works okay. It shines light on one area of fitness and can be re-tested again and again to check for improvement.

By definition, your FTP is the power you could sustain for one hour, full gas. I say could sustain because who’s going to go all-out for an hour to find this value? So it’s become common place to go hard for 20-minutes and subtract 5% from your average power. Pretty much the Gold Standard, and everyone accepts it. Even going all-out for 20 minutes is pretty tough on your own. For this reason, more recent models are doing one or two 8-minute intervals and subtracting 5-10% from those averages to estimate FTP. All said and done, these methods of FTP testing highlight one energy system (Vo2 max). On top of that, they calculate the FTP from a “one size fits all” percent reduction from the test effort. From here, it doesn’t tell you much else. Does it work? I suppose. However, if you’re like me, you would likely prefer more.

What if we said we can offer you another, possibly better, way to test on the bike to gain insight on your fitness, set zones, and track progress?

Anaerobic Power vs. Aerobic Power Testing

Over the last 10+ years of training and coaching with power in our trainer studio environment we have found a different way to perform power testing that presents us with more insight on a rider’s fitness and sets more personalized training zones.

Every endurance athletes is different. Each comes to the sport of cycling from different backgrounds of sport and a different set of physiological strengths & weaknesses.

To generalize, we can look at endurance athletes as two types:

1. Strength/Power Based Athlete: strong, powerful, can crush it for a few seconds (sprint!) to a few minutes, but then power drops off rapidly and they slow down from there. These athletes typically come from power/speed sports like soccer, football, or wrestling, or were “sprinters” on the track or in the pool in their youth; often larger and more heavily muscled builds.
2. Aerobic Based Athlete: not particularly snappy, but can churn out the steady power and can go all day long with minimal drop in speed/power. These athletes often were the “slow” kid on their teams growing up, enjoyed hiking or longer distance running and swimming events; or as adults have only done long (slow) endurance training/events over the years. Commonly a smaller and leaner build.

Have each of these different athletes perform an 8 to 20 minute max power test you will be taxing them in different ways. The Power Athlete’s test results will likely result in the aerobic power values to be a bit high, and their top-end power values to be a bit low; whereas the Aerobic Athlete’s test results will likely result in power values on the top-end (vo2 max/anaerobic power) being too high and on the lower aerobic end to low.

What’s important to consider here is that for endurance athletes of all types, the goal is to produce the most power possible over the duration required for the event. Put another way… maximize the power, while minimizing the decline in power as durations extend.

In general, those that typically win endurance events are the ones that SLOW DOWN the least!!

Our testing protocol takes this concept into account by identifying the individuals rate of fatigue. That is how much their power drops between two test intervals of increased duration. We use this Fatigue Rate to calculate their power training zones (including an “FTP”). At the same time, our test shines light on where they are at on the “Power vs. Endurance” curve to better show where they should focus their training efforts. The short duration testing intervals we use for this part of the test allows us to specifically identify and track the riders top-end anaerobic power capabilities, and at the same time determine their rate of fatigue.

To keep tabs and monitor progress on the other end of the spectrum, the aerobic endurance or “fatigue resistance” end, we include an Aerobic Threshold (AeT) Test interval as part of our testing protocol as well. As you can see, there are two parts to the training equation, Power vs. Endurance, so we should have two parts to the testing protocol.

Your Aerobic Threshold, the key to Fatigue Resistance

As discussed in a previous post, Training With Power or Heart Rate?, I mentioned a few of the primary objectives of aerobic training. These include: improvements in cardiovascular infrastructure (stronger heart, more blood vessels, more mitochondria, etc), and improvements in energy metabolism by increasing the use of fat for fuel and sparing glycogen at higher and higher outputs. Big power numbers are cool, but in the endurance sport world fatigue resistance is king.

Aerobic fitness is the ability to resist fatigue and minimize one’s Fatigue Rate.

With a lower Fatigue Rate an athlete’s power drops more slowly over time. Therefore riders can keep pushing the pedals harder, creating more power, for longer.  Improving or maintaining that balance between power and endurance is crucial to your success. If you improve power at the sake of a loss in aerobic fitness you may not have actually gotten any faster at your target race intensities. This is why you must always keep tabs on your power at Aerobic Threshold (AeT) to be sure you aren’t increasing your Fatigue Rate any more than necessary.

In training our goal is then two-fold:

1. Improve both your top-end speed & power through strength & plyometric training in the gym, and through high-intensity intervals on the bike

2. Improve your aerobic fitness so you can utilize more of that power over longer periods of time by minimizing the decline that occurs as you fatigue.

To test an athletes AeT power, we include an AeT test interval in our testing protocol. The test requires an athlete to focus entirely on riding at their identified AeT Heart Rate for an extended period of time. Then we look for the average power that was a result of the aerobic effort. The overall goal is to improve your aerobic power to keep your Fatigue Rate as low as possible while at the same time increasing your anaerobic power to give you a higher starting point of power to utilize across all durations. There in lies the tricky balance of training and maximizing performance!

Written by Cody Waite, professional endurance athlete, endurance sport coach and founder of Sessions:6 Sport Performance. Looking for help with your endurance sport training? Check out S:6’s Training Plans, Team Programs, and  Personal Coaching options created to fit your needs and budget.