What is VI and what info does it give you? Sorry if this is a dumb question.
VI - Variability Index - Normalized Power/Average Power. It is an indicator of how varied your power output is during a ride. Vary important in teaching yoursefl to pace a solo time trial effort correctly - no meaning at all in a group ride.
Uh Oh. The questions continue. What is normalized power? What is a good VI reading or is that dependent on the rider?
Interesting. Why do they choose that as the measure of variability instead of something like a coefficient of variation?
here you go…
Uh Oh. The questions continue. What is normalized power? What is a good VI reading or is that dependent on the rider?
A good VI is dependent on other variables. Most specifically, course terrain. It is my opinion that you can never look at VI alone and say, “That was a good or ideal VI for that course” without evaluating other variables within your power file. However, it’s easier to make a blanket statement when you see a “bad” VI. For example, we often see VIs in excess of 1.1 on courses like IMWI, IMC and IMLP. So I can safely say that a VI of 1.12 is far from ideal (bad) for any athlete on any of those courses on any day.
That’s the best I can do in a paragraph. In order to fully understand the extent on this conversation you really need to spend time learning the principles behind the Normalized Power (NP) concept.
That Power411 link is a great place to start.
Thanks, Chris