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Lisa is sick, I’ve got a touch; New FTP established yesterday.

Thursday, August 21, 2014 by  
Filed under Daily Blog


Lisa’s been sick all week, and yesterday she went to the doctor. Diagnosis: two ear infections and some sort of virus. She’s on antibiotics now, and can’t go back to work until Friday.

There’s no question I’ve got whatever it is Lisa has, although so far it’s not affecting me too much. Yesterday morning I woke up with a slightly scratchy throat, and feeling a little run down. I’ve been going to bed a little extra early and, of course, keeping my diet clean and healthy. This morning I feel about the same as I did yesterday, not great, but far from incapacitated.

When I set off for my morning ride yesterday I didn’t have a concrete plan. I figured I’d see how I felt during my warm-up, and go from there.

I say I didn’t have a plan, but that’s not entirely true. A strong local rider, Paul, recently created a very cool 13 kilometer (8 mile) segment that has just 4 turns, all right handed–perfect for time trialing. Paul has been taunting me and several other locals (Hi David!) to ride it. I definitely had that segment in mind when I rolled out yesterday.

I didn’t feel great as I warmed up, but as I approached the start of the segment I thought, “Okay, fine… why the hell not?” The next thing I knew my heart rate was over 180 BPM, and I tried to settle in at a little over 300 watts for what was going to be a painful ~20-minute effort.

About five minutes into the effort I thought, “Damn, I there’s no way I can sustain this for 20 minutes”, so I knew I was precisely where I needed to be. 🙂 Seriously, every time I do a threshold/supra-threshold ride of any length I feel this way early on. The trick is to push past the pain and settle in, taking it one minute at a time.

I didn’t set out to re-test my FTP, but the 8 mile segment length is almost perfect for the 20-minute FTP test.

Before I get into my results, here’s a quick recap of FTP (Functional Threshold Power) and the 20-minute test.

Functional Threshold Power is the maximum average power an athlete can sustain for one hour. Because riding at threshold power for one full hour is extremely difficult (if not impossible) in a non-race situation, there are a couple of shorter standardized FTP tests: the “8-minute” test and the “20-minute” test. These tests are designed to accurately estimate an athlete’s FTP with either two 8-minute supra-threshold efforts, or a single 20-minute supra-threshold effort.

The formula for the the “8-minute” test is:

FTP = ((P1 + P2) / 2 * .9)

…where P1 and P2 are the average power outputs from each 8-minute interval.

The formula for the the “20-minute” test is:

FTP = (P1 * .95)

…where P1 is the average power output from the 20-minute interval.

My maximum 20-minute average power on yesterday’s ride was a new personal record of 306 watts (click to enlarge):

Yesterday's 20-minute FTP test (done outdoors): 306 watts average power.

Yesterday’s 20-minute FTP test (done outdoors): 306 watts average power.


So, using the simple “20-minute” test formula I can determine my new FTP:

(306 * .95) = 291 FTP

While not a huge leap, 291 is a new FTP personal record for me. My previous best FTP was 288, which I set the last time I tested (April 2014). I’ll take it!

For completeness sake, here is all the ride data from yesterday’s 20-minute effort:

Average power: 306 watts
Maximum power: 821 watts
Average speed: 38.79 km/h (24.1 mi/h)
Maximum speed: 50.05 km/h (31.1 mi/h)
Average cadence: 104 RPM
Maximum cadence: 118 RPM
Average heart rate: 177 BPM
Maximum heart rate: 185 BPM

20-minute test ride data.

20-minute test ride data.


You can clearly see three of the four turns (one of the 4 turns is in a bike lane with no cross-traffic, so no slowdown is required) in the above graphic–that’s the only time my cadence drops.

I should mention that I actually completed the segment in 00:19:40 with an average speed of 39.11 km/h (24.3 mi/h), so part of my ride leading into the segment was captured for the 20-minute effort. I wasn’t riding at speed during part of that time, and that cost me a watt or two. Next time I do the segment I’ll ride at power for the full 20 minutes.

While I’m happy with the new power output personal records, I feel I’m capable of more. I was definitely not feeling 100% yesterday, and so I’m going to do this segment for time again in the near future. I’d love to see my FTP at over 300 watts this year. That would require an average power output of 316 watts for 20 minutes.

My current power output PRs, scale weight and FTP can always be found on the Power Output page, which is under “Cycling” in the main menu (above).

John Stone Fitness Comments

3 Responses to “Lisa is sick, I’ve got a touch; New FTP established yesterday.”

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