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05-06-16, 06:40 AM

#30

Heathpack

Has a magic bike

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Quote:

Originally Posted by DrIsotope

All I know at this point is that the addition of the Stages has given me a whole bunch more numbers that I really don't know what to do with. Actual recorded power numbers are above pre-meter Strava estimates on my handful of recorded rides, but I've simply lacked the gusto to attempt an FTP test... so I have literally no idea what to do with the numbers, or even what numbers to shoot for. The instantly available power data has, if anything, made Z2 riding (which was easy on HRM alone) really difficult, because (in my limited use so far) there is absolutely no relation between HR and power output. I've averaged 244w (unweighted) at an HR average of 128bpm (which for me is barely out of Z1) and also averaged 242w (unweighted) at an average of 147bpm. So I have yet to determine the relation. The ride I brought in the screenshot below had a lot of wind swirling, so I think that's some of the higher HR/lower speed relative to others, but I'm more interested in figuring out the power numbers.

I also don't know what to focus on-- weighted numbers or unweighted numbers. Strava also apparently estimated my FTP for me at 287w (I have no idea if that's applicable to anything, but regardless. This is from yesterday on the 4th. Some of these numbers I get, some mean nothing to me. Training load? Intensity? Wuzzat?

How long have you had the power meter? Strava estimates will be pretty decent with enough data- like a few months worth. An FTP test would be better.

Why did you get the power meter? What goals were you hoping to achieve by getting it? Or did you just get it because it was affordable & you just wanted to see what you'd be able to do with it?

Here's how I use my power meters (I know my FTP is set correctly):
1. Set power targets for interval workouts and TT training efforts
2. Quantify training intensity of unstructured rides, sometimes to stay within a certain intensity and sometimes just to track training stress
3. Track calories burned
4. Keep on top of overall training load, which helps to plan rest & when you will be in peak performance for an event (in reality my coach does this better, so I don't care too much about this)
5. Pacing, especially in a TT
6. Communication between myself & my coach.

Power meters can also be used in aero testing.

Weighted average power is the same thing as Coggans' normalized power- its an algorithm that corrects your average power to account for the extra physiologic "cost" of surges in effort. Generally speaking, it's more relevant than average power.

Intensity is your average (or maybe weighted average) power for the ride divided by your FTP. It's a measure of how hard you rode. Strava seems to also use HR data to come up with this number. 89% for 4.5 hours means you rode really hard. If your ride did not seem really hard, your FTP might be set too low or there could be another issue with your data. Typically a 4.5 hr ride would be ridden at around 65-75% intensity if you were being casual about it.

Training load is another algorithm, I don't remember the exact formula- but it takes into account the power output and duration, then Strava tracks the cumulative effect of each ride's training load and compares your acute training load to your chronic training load to come up with a training stress balance. Basically this helps to determine when you're in peak form (TSB is close to zero, say -2 to +10), when you need some rest (TSB is negative -40 to -60), and when you really need to get back to training (TSB is a high positive number, say +20 and above).

Power and HR correlate somewhat but they tell you different things. Power changes instantly and HR changes slowly. HR is influenced by emotional state, heat, hydration, fatigue. Power is not. I often use HR as a check against the power data, but not a primary thing- for example, in an FTP test or a TT, I might wonder if I could have gone harder. But if I had my HR pegged at LTHR within the first 2 minutes and it stays there unwavering, I know I got that effort right. Otherwise, I might use HR to assess emotional state (adrenaline rush at the beginning of a TT for example, which will change your perception of your power output) or to assess hydration status on a long ride.

All this stuff is in the book Training and Racing with Power by Coggans. And in a more piecemeal manner on the Training Peaks website.

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