Originally Posted by patentcad

Here's an example of why a power meter can be interesting and valuable. Today I felt better on the bike than I have in a long time. So tonight I finally get around to downloading the Powertap file from today's 78 mile ride. 4400 feet of climbing, Nyack Ride, that should be a tough ride for me. But not today. Today it was easy. The Powertap file showed 30 and 60 minute peak power output numbers that today matched my highest numbers in two years of those files, which include many hard group rides and races. So the power meter can tell you, yes, you did feel good today, or no, the numbers don't quite add up.

Today they confirmed how I felt on the bike.