Monday, March 18, 2019

Stryd Critical Power Test

Just did my first Stryd power test. This is how you determine your critical power and affiliated running zones. So far, I was using zones based on an old (6 months ago) 5K race. To do the new power test, I was waiting to run on the local high school track, but that darn thing has not been open to the public whenever I try to go. So, today I ran on the Kickapoo Rail Trail. It's flat, packed dirt, and straight. Few trees. Very good GPS signal. Just run straight and keep an eye on your watch.

Stryd has a set protocol for these power tests--one using the track, the other timed on flat surface. Basically, you warm up with easy running for 20+ minutes, do some strides, then get ready to run. Hard. I did 9 minutes hard (instead of 6 laps on 400m track). Rest for 20+ minutes (easy jog or walk), then run hard again for 3 minutes (or 3 laps on track). Save each hard effort on your watch so you can track distance, time, pace, and power (from Stryd foot pod). This was my first power test...and I did not optimize my hard running. Supposed to be a consistent hard effort that you can maintain for the full 9 minutes (or 3 minutes). I charged out too fast, then hung on as best as I could. I wasn't terrible, but not ideal. I need to hold back next time and show some discipline! Also, my rest interval was less than 20 minutes. More like 10 minutes. I was not fully rested when I did the second 3-minutes hard (it was also into a slight head wind). Next time I will rest properly and pace myself for the full hard effort(s). Think I'll find a slightly warmer day with no wind and repeat this power test.

I entered all the data into the Stryd power center and it calculated my new critical power and zones for running (critical power = 323W, critical pace = 6:47 min/mile). The new settings are higher than my previous ones based on the old 5K race. Still, I think my average pace could have been faster with more even pacing. This test is actually a great speed workout. And not so taxing that you can't return to normal training within a couple of days.

Tips for others (or me) to do a critical power test correctly:
Avoid any extreme weather: wind, rain, heat, cold.
1. Go easy the day before your power test (nothing long, no speed).
2. Do a lengthy and relaxed warm-up (~20 minutes).
3. Don't forget the strides (4-5) after warm-up.
4. Go hard, but don't sprint, on the first speed effort (6 laps or 9 minutes). Time/measure each hard effort separately.
5. Take a long break, as long as needed. Preferably 20-30 minutes (walk and/or jog).
6. Go hard again on the second 3-lap test (or 3 minutes), try even harder since it's shorter (but still no sprint).
7. Cool-down however you want. It's over. Don't skip the cool-down.

Good luck to anyone doing the Stryd critical power test. Good luck to me repeating it. I'll probably do a new one every 6-8 weeks to keep zones accurate and up-to-date.


Anonymous said...

Hi Chris,

Great article, I have struggled to find any good examples or vidoes for a Newbie on using stryd and doing the CP test

I have a question what do you mean bt this part?

"3. Don't forget the strides (4-5) after warm-up." ?



Chris Ⓥ said...

After the easy warm-up, you are supposed to run 4-5 strides (very short 50-100m accelerations) to prepare for the real speed session. Basically short sprints--but not full out 100% sprints. Effort around 90% of top speed.

Patrick Duchesneau said...

You wrote "a little head wind". Next time, do it on a race track. Head and tail wind will roughly compensate each other.

Chris Ⓥ said...

Good idea. Will do track next time. Now Stryd has auto calculate and updates your critical power based on all of your runs. Still, I like the ide of doing a "real" CP test every once in a while.