Forums >General Running>Does anybody use Joe Friel's efficiency factor?
Joe Friel uses an "efficiency factor" to measure improvements in aerobic fitness. Does anybody actually use it? Is it useful?
BTW, if you do the math, it comes out to yards per heartbeat. A different way of measuring the same thing is to multiply heart rate times pace in minutes per mile to get heartbeats per mile.
Interesting idea. Didn't know about it, but how do we use this to help our running? Do we try to train at the most efficient factor, or do we race at that number? is there a length of race which determines if we should try to run at that most efficient factor?
No, you don't try to run at it. From my understanding, you use it to see how your training is progressing. Take a course that you run on frequently and compare the EF over time. If the efficiency factor goes up consistently, it implies that you are becoming more aerobically fit.
If it is going down, then you are losing fitness. To compare accurately, you need to be going into these runs with similar background (sleep, hydration, caffeine status).
If you use one of the canned softwares like Training Peaks, the EF is calculated for you and you can compare similar workouts from different days to see whether this number is improving.
I think many people do a similar thing when they try to determine whether their regular easy aerobic pace goes down with training. If it does, they assume that they are progressing. The problem with that is that "regular" aerobic pace can vary a lot with terrain and other factors. EF uses a "graded pace" concept which takes into account hills.
Let me give you an example...I ran a hilly course 3.5 miles uphill with an efficiency factor of 1.3 but coming downhill the EF was only 1.02! Clearly it is difficult to maintain the same level of intensity coming downhill, and thus the normalized graded pace is much slower. The software views this downhill portion of the run as highly inefficient. It wouldn't make sense to compare these two runs with each other in terms of improvement except to say that I could learn to push the pace downhill and become more efficient. It would make sense to compare just the uphill parts and see that 9 weeks ago I ran with an EF of 1.1 and now I ran it at a 1.3, presumably an improvement in aerobic fitness.
"Shut up Legs!" Jens Voigt
Thanks for the explanation, too bad that Training Peaks does not support Garmin.
? I upload stuff from my Garmin to Training Peaks all of the time. They are not the only game in town, though. There are some other programs out there that calculate all sorts of (useful/useless) parameters. Or if you want to spend a whole lot of time you can make your own spreadsheet.
Thanks again, not sure how I missed that "Connect powered by Garmin" was the first on supported devices page, I guess I was looking for Garmin logo or something If I can just upload the files from gGarmin, I'd look into it. More for my family who are now showing some interest in hiking/running than for me.