I always advise clients to invest in a power meter after they’ve gotten a bike fit and have signaled their intention to take their cycling to the next level. A power meter is the single most effective and accurate training tool you can have in your arsenal, and it will help you become a faster cyclist more than fancy wheels or a nice helmet. But knowing how it works, and how to use it in training and racing, is the key. Without that knowledge all a PM does is show you a bunch of numbers that may or may not mean anything to you.

 

Should I ditch my Heart Rate Monitor?

Heart Rate Monitors used to be the #1 training tool of cyclists and runners, but its limitations have made it lose some of its luster especially among techie athletes who have either had too much of the power meter kool-aid or weren’t truly using their HRM’s properly. Personally, I believe in using BOTH tools as much as possible as they give a better picture of what your body is going through, especially for tests to determine aerobic coupling.

In a nutshell, Heart Rate lets you know how hard your body is working, and Power lets you know the actual work your body is producing. Heart Rate is “INPUT”, Power is “OUTPUT”. That said, the delayed Heart Rate response to shorter, harder efforts makes it largely useless for anaerobic efforts (but still useful for tracking recovery), and a user has to know how HR is affected by heat, dehydration, and adrenaline so he can pace accordingly.

A Power Meter, on the other hand, gives instantaneous feedback to the point that the change in wattage every 1, 5, or 10 seconds can drive the uninformed user crazy, especially if he is trying to maintain a certain wattage. This is most especially a problem if he is trying to beat a friend’s wattage output without even considering (much less understanding) the power-to-weight ratio! What he should be more concerned about is the ability to hold a certain wattage RANGE throughout a given interval, and tracking the increase in wattage, and by extension PWR, over time or the ability to hold it for longer and longer durations.

 

The Power Profile Test

To get started, it’s very important that the novice PM user conduct a “Power Profile Test”. This takes around an hour and half to finish, and involves taking down your average power over the course of several, efforts: 10 seconds, 1”, 5” and 20-30”.

The book “Training and Racing with a Power Meter” by Hunter Allen and Andrew Coggan explains this in detail, but to summarize: the Power Profile test measures your wattage output over several ranges: Neuromuscular (full sprint), Anaerobic (extended sprint), 5” (V02 Max or Aerobic Capacity), and Functional Threshold (your “Time Trial” output).

To do it properly, do the following workout:

1. Warmup for 20-30” in an easy gear
2. Ride at a steady, moderately hard effort for 10” building to Tempo by the last 2”.
3. Test 1, Neuromuscular: Sprint (full blast) from a rolling start for 10 to 15 seconds. Catch your breath for a minute or two, and repeat 2 to 3 more times.
4. Test 2, Anaerobic: Stand out of the pedals and quickly accelerate to at or near full speed ahead, and hold the effort for a full minute. REPEAT this test 1 or 2 more times, giving yourself 2-3” rest intervals.
5. Test 3, V02 Max: Stand out of the pedals and smoothly accelerate, building your effort until you are going are hard as you can by the 3^rd Hold that effort until the 5^th minute.
6. Test 5, Functional Threshold Power (FTP): Give yourself at least 5” easy spinning after the V02 Max test. Steadily accelerate until you are Time Trialing (comfortably hard) for 20-30”. It’s easy to blow up in the first 10”, so be on the side of conservative. Once you find your rhythm keep holding the effort. Resist the urge to sprint in the last 1” thinking you can “bump” up your wattage. You might end up with an impressive number, but remember that you’ll be trying to duplicate or better this effort regularly in training!
7. For test 5, multiply the average power by .95. This gives you a fair approximation of what your output might be like had you time trialed at threshold for an hour.
8. To get the best results, ride on a course with a false flat or modest incline.
9. It’s especially useful to take down your average HR during the Functional Threshold test. Getting your Functional Threshold Heart Rate (FTHR) gives you a reasonably good gauge of your engine input on the occasion that you can only train or race with a Heart Rate Monitor.
10. Periodic testing of FTP and FTHR lets you track improvements in fitness (ie, increasing the output while holding the same FTHR).

 

Once you’re done, your next step should be to get the highest average wattage from the tests, and divide each number by your weight in kilos. This gives you your Power-to-Weight Ratio for each power level. I also recommend doing these tests with a Heart Rate Monitor so you can see how the cardiovascular system responds under varying loads and intensities.

You’ll quickly find that a full power, 1 minute anaerobic effort will produce relatively high wattage but the HR response time will lag. Any time you shift from an easy effort to a significantly harder one, the PM will show an instantaneous change in OUTPUT while the HRM will have a slight delay of 1 to 2 minutes before the “INPUT” catches up to the effort. From this you can determine that anaerobic efforts and even brief forays into V02 Max (aerobic capacity) surges of 3 to 4 minutes will essentially render HR useless until after the fact, so you can then note how quickly your body recovers between intervals.

Now that you’ve done your Power Profile test, your next step should be to compare your results with an established benchmark. In this case, I like to refer to Allen and Coggan’s table of PWR benchmarks which they standardized based on hundreds of athlete’s power data.

 

By getting your power for each test result and dividing it by your weight in kilos, you can then determine your strengths and limiters as a cyclist as well as see how much more you can improve. Should you lose some more cheese? Gain more power? Both? Looking at the chart and assessing your own body mass composition and body fat percentage gives you a better idea of where to start.

For example, most Age-Group triathletes will tend to have good PWR for Functional Threshold, but relatively low PWR for 5” V02 Max and 1” Anaerobic efforts as they primarily train in moderate, sustained effort riding. Roadies, on the other hand, especially the climber types, will have high 1” and 5” PWRs, but may not necessarily have good PWR at FT if their style of riding is more of the hiding-and-attacking kind than steady state time trialing.

Regardless of your strengths and weaknesses, the Power Profile test establishes your baseline fitness across different output levels. Remembering the principle of Specificity of Training, you can then determine how hard you must work, for how long, and for how many repeats, in order to create the desired training effect.

Do you need to work on your Time Trialing? Then you need to ride at or near FT for at least 8 minutes at a stretch, working to a total of 40 minutes to an hour depending on your rate of recovery. Do you need more top-end speed? Then you should focus more on anaerobic intervals.

Finally, the beauty with training with a PM is that it simplifies the other question in many athletes’ and coaches’ minds: how many times should I do these fricking intervals?

The answer lies in the open secret of weight trainers: “When you cannot do any more.” In other words, when you reach the point of muscle failure such that you cannot ride at the target intensity any more. When we do a simple strength training exercise like a pushup, we stop when we can’t lift our torso off the floor anymore. When riding with a PM, you stop the interval set when you either cannot hit the desired wattage range or the recovery time takes longer than usual. (NOTE: Recovery intervals are usually on a 1:1 basis, except for lower efforts such as Tempo where the ratio can be 1:1/2 or just a few minutes).

Here, we can again refer to Allen and Coggan’s guide to interval training to know when it’s time to call it a day. You’ll have to do some mental math during a ride, and the computation is done after the 3^rd interval to determine whether you should continue or not.

 

Charting your wattage range over the various levels and knowing the appropriate duration for each interval will help you to get the most bang for your training buck. Just remember that the shorter the interval duration, the higher the output and vice versa. If you have been just pedaling along before you got your PM, you may be surprised how hard it is to actually sustain a specific wattage range for a specific length of time. Like the great Greg LeMond famously said, “It never gets easier. You just get faster.”

*Ref: Power Profile Chart, “Training and Racing with a Power Meter, Vol. II”, Hunter Allen and Andrew Coggan

 

NOTE: Because of the extended recovery that high intensity intervals require, I’ve found that a “safe” limit to the total time at intervals can be used for the following intensities:

1” Anaerobic : 12-16 minutes

3-5” V02 Max: 15-20 minutes

8-30” FT: 30-40 minutes

Limiting total training time at these intensities creates a powerful training effect, while still moderating the amount of stress the average AG’er can handle so he or she can still get up for the next day’s workout!

The author is Director and Head Coach of Alpha Training Systems, a high performance online coaching program for Age Group cyclists and triathletes. He can be reached at alpha_tri@yahoo.com and alphatri@twitter.com

References:

“Training and Racing with a Power Meter, 2^nd Edition”. Hunter Allen and Andrew Coggan, PhD.