PezCycling News - What's Cool In Road Cycling : Toolbox: Power Profiling

To get to where you want to go this year, you need to know where you are now in terms of your fitness. Information is power, and the whole point of training with power is to provide as much information as possible to guide your training. One important path towards this self-knowledge is through regular testing and determining your power profile.

Do As I Say, Not As I Do!
As an exercise scientist with all the tools of the trade at my disposal and the theoretical knowledge to use and interpret those tools, I can be guilty of taking them too much for granted. That is, after 25 years of riding and lots of different fitness tests over the years, it’s easy to assume that I know exactly what my body is capable of.

I have done VO2max tests since starting my M.Sc. in 1992, and have irregularly done lactate threshold tests on myself as part of various experiments. Also, I have used a heart rate monitor since 1989 and also a powermeter since 2006. Therefore, that’s a lot of data that’s accumulated! For instance, I know that my time trial heart rate for 20-60 min is always hovering right around 155 beats per minute, just like I know that my maximum heart rate was 173 for much of my 20s and 30s, and has dropped to 165 the past few years.

With that inherent knowledge, I still have to confess that, despite logging my training using TrainingPeaks WKO+ software since 2006, I haven’t done a great job of tracking my power capacity and profile, generally just ballparking that my functional threshold power (FTP) is about 250W. Worse, I’ve generally assumed that it’s pretty much constant throughout the season and over the years. The classic “do as I say, not as I do!”

Back on the Testing Wagon
A few things converged this past fall to shake me out of this pretty non-scientific approach to quantifying my training. First, working on a book about the science of cycling, it was time to walk the walk. Second, I was invited by Hunter Allen to present at his Fall training camp in October in Boiling Springs, Pennsylvania, where the entire focus was on power testing and program development based on the testing.

With Hunter Allen in Pennsylvania - all smiles before the scientist becomes the guinea pig

Finally, CycleOps was kind enough to send me their new combination wheelset pairing their SL+ PowerTap hub built to a set of DT Swiss 465 rims. Not the lightest wheelset out there, but rock-solid and easily repairable set if anything untoward did happen, as they utilized standard 32-h DT double-gauged spokes in a standard double-crossed lacing pattern. Slick lightweight wheels are great and all, but having a durable set that I can ride in all conditions is much better for overall peace of mind when we’re talking training. Plus, as an extra test, I subjected them to a full fall season of both training and racing cyclocross on them with nary a wobble on the rim or indeed any concern. Given my technical abilities in CX, that’s high praise!

The wireless PowerTap SL+ was a big upgrade in user-friendliness over my previous wired model – no more cluttering up my bikes and even simpler to switch between my road and CX bikes.

The best thing about the new SL+ is the simple switching between the two cassette bodies. No tools needed – just pull with your fingers and the body slides out of the cams! This fall, it took me less than 5 min to switch wheels between my Campy-equipped De Rosa road bike and my SRAM/Shimano-equipped BMC cyclocross bike, and that included time spent swapping tires!

Not surprisingly, the DT-Swiss 465 rims were built with DT-Swiss spokes, and proved bombproof on both road and CX

With this perfect storm of events, I set out to see exactly how I stacked up to the testing regime outlined in the 2nd Edition of Hunter Allen and Andy Coggan’s Training and Racing with a Power Meter .

Functional Threshold Power
In Allen and Coggan’s world, the main parameters for regular testing consists of average power over 4 distinct time points: 5 s, 1 min, 5 min, and 20 min. The 20 min test is then used to calculate Functional Threshold Power (FTP) by multiplying it by 0.95. FTP represents the maximal average power you can sustain over 1 h, and is one of the most important values around which power training is based. That is because FTP becomes the 100% benchmark around which all the training zones are calculated.

Shootout at Boiling Springs
We were treated to a week of terrific weather while at camp. Therefore, each day was built around doing specific training and learning, with testing for determining our power profile built into each day. For example, our first consisted of low-speed bike handling and bumping drills, followed by a ride out to King’s Gap State Park for 1 min and 5 min testing.

While the great outdoors are difficult to use as a reliable basis for field testing, due to changes in terrain, wind, and traffic, King’s Gap was pretty much the perfect testing site. The road was smoother than a billiard table, and the grade was a consistent slight rise of about 2% at the bottom and a moderate 4-5% for the bulk of it. Plus the massive forested canopy pretty much blocked wind from all directions.

Lining up at the bottom, we did a flying 1 min effort to start. I took the effort with an “all-out” pacing strategy, where I started with a near-maximal sprint out of the saddle, sat down smoothly and then tried to hang on for dear life for the remainder of the minute. What did I learn?

First of two 1 min maximal efforts. Yellow is power, green is cadence, blue is speed, and red is heart rate. Note the "all-out" strategy of having a hard initial burst and then hanging on with a slowly decreasing power.

- You can’t escape. Regardless of strategy, the last 20 s last forever and hurts like hell.
- Do not over-gear and keep your cadence high if you want to keep your power high.
- Peak power was 989 W, and final average 1 min power was 489 W. With a 65 kg mass, that equated to 7.52 W/kg. This puts me smack in the middle of the “Cat 4” or “Moderate” range in the Allen and Coggan power profile chart.

The other interesting experiment was repeating the 1 min test after 5 min easy recovery. Rather than the all-out strategy, I deliberately tried to not go as hard in the initial burst, averaging only about 550 W for the first 20 s (compared to 680 W for the first 20 s in the first effort). What did I learn this time?

Second time running the 1 min gauntlet. Same "all-out" strategy, only the numbers are lower throughout.

- If you’re going to commit to an all-out strategy, you can’t do it half-assed. Going at 550 W meant that I still hurt as badly as the first attempt, but was going slower and less powerfully throughout. In essence, I never re-gained the “lost” power from those first 15 s. Subjectively, I never felt on top of the gear and was thrashing it instead.
- I have very poor anaerobic recovery. Indeed, my second effort was only 418 W, a full 71 W decrease compared to the first attempt!

5 min of Pain
The 5 min effort was quite different in feel from the 1 min. The 1 min is really just getting tackled by a NFL linebacker type of instant and intense pain. In contrast, the 5 min is more like getting wrapped by a boa constrictor, where the pain increases relentlessly but more gradually, to the point where you almost don’t notice it. It also helped that the climb was so beautiful with the fall colours beginning to bloom, although I did my best to keep my eyes on the task. What did I learn?

5 min effort up a 4-6% steady grade. No huge initial spike of power and just a steady hard effort.

- I kept a focus on maintaining a high cadence, doing the bulk of the climb in 50x21 or 23 near the end.
- Needless to say, there were no heroics of an early burst of 900-1000 W. I started at about 400 W for the first 30 s, then kept my eye on the average power reading on my CycleOps Joule.
- It’s amazing how the body follows the brain. Not having really done a 5 min test before, I made an educated guess of 300 W average. Lo and behold, my final average was 305 W! Perhaps this is just coincidence, but it might also be a case where I might have gone harder if I hadn’t already subconsciously “planned” my effort before I even turned a pedal. This can also work both ways, as perhaps I forced myself to match my initial plan of 300 W, even though it’s harder than what I would have done without seeing the power output on my computer.
- The 305 W resulted in a 4.71 W/kg result, putting me solidly into the middle of the Cat III or “Good” range in Allen and Coggan’s profile.

20 min Sounds Fun, Right?
Why use a 20 min test to estimate FTP? As any time trialist knows, going “on the rivet” for a full 60 min time trial is extremely demanding both physically and mentally, and asking riders to do such a stressful effort every 4-6 weeks over the course of a year can be a tough sell. Therefore, the 20 min test is substituted in favour of doing more frequent and regular testing. Not that a 20 min test is a coffee shop ride by any means, of course!

We did the test on an initial rolling stretch, leading to a steady 6-8% 15-17 min climb. Such an effort again highlights the difficulty with finding a consistent outdoor testing site with a consistent long stretch of road. Reviewing the power data, the first rolling stretch was indeed very inconsistent in power output, as it was nearly impossible to sustain a high power output even with a 2% decline. This led to some indecision about how to tackle the pacing. Do I go hard to maintain a high average wattage in the initial stretch, perhaps risking blowing up on the climb? Do I take it somewhat steady and let the average wattage be lower than expected, and hope that the average wattage climbs once the hill arrives?

The jagged initial 5 min highlights the difficulty in pacing with uneven terrain. It's easy to see where Waggoner's Gap climb begins, with the very steady power profile and speed.

- In the end, I did the rolling stretch at about 255 W, then averaged 277 W over the 17 mi climb itself, for a total time of ~23 min and average wattage of 268 W. It does make estimating an actual 20 min effort rather difficult.
- In the end, I split the 268 and 277, pegging my 20 min wattage at 273 W and FTP at 258 W. This gave me 3.97 W/kg for my FTP, again in the middle range of the “Good” Cat III in the power profile.
- Since I seem to be a connoisseur of pain, the 20 min test is, for me, psychologically worse than the 5 min test. The pain feels about the same, but the effort is so much longer! For me, the worst seem to be between minutes 7-15, as the end isn’t anywhere in sight and all you have to look forward to is more of the same agony.

Me The Next Cav?
Not bloody likely. We did a third day of sprint-specific training, where I logged my peak 5 s power output at 1092 W, or 16.8 W/kg. Repeating a theme, this puts me again in the middle of the “Good” Cat III range, so I can skip booking my flight for the Champs Elysee sprint any time soon.

Indoor Testing
As you likely know, the key point of reliable testing is finding a set of roads where weather, wind, and traffic don’t wreck your ability to sustain maximal effort throughout. This can be extremely tricky outdoors, as even a slight dip in the road makes it very difficult to sustain max wattage. That’s why I’m a big fan of testing on the indoor trainer. This is made even more practical with the popularity of power monitors, as you retain the ability to measure the full suite of testing data like power, cadence, heart rate, etc. If you don’t have a power monitor but you do have a CompuTrainer, a great addition is the ErgVideo Threshold Test DVD, which provides you with a solid standardized testing protocol and give you average power data.

Since I’m not going to be back at Boiling Springs for the next little while, my future testing will be conducted indoors using my CompuTrainer, ErgVideo, and PowerTap. Next week, we’ll interpret the information that we can glean from your power profile. Plus, we will see what my testing values look like after a month break over December, with a view to seeing what happens to your fitness after detraining and holiday merriment.

In the meantime, have fun and ride safe!

p.s. Thanks to the Peaks Coaching Group for hosting and inviting me to present at their Fall Camp, and to for providing the PowerTap SL+ wheelset with the Joule 2.0 computer.

About Stephen:
Stephen Cheung is a Canada Research Chair at Brock University, and has published over 50 scientific articles and book chapters dealing with the effects of thermal and hypoxic stress on human physiology and performance. He has just published the book Advanced Environmental Exercise Physiology dealing with environments ranging from heat and cold through to hydration, altitude training, air pollution, and chronobiology. Stephen’s currently writing “Cutting Edge Cycling,” a book on the science of cycling, and can be reached for comments at .


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