Automatic FTP

I use a Quark PM, so I set the FTP setting to manual. So I haven't messed with Auto FTP.

Since you are using a PM, I suggest you also set it to manual and do a full FTP test for all the reasons I suspect you already know. You must have been going harder than you thought!

LOL...

Congratulations on your 520 purchase! ;)

I use power with my 520 but don't know what my FTP is set to on the 520 as I don't look at any metrics that need FTP. I load the data into Golden Cheetah after rides and have my FTP stored there.

OK, I just looked and my Garmin is set to Auto and it's at 295. That's close to the 290 I was using.

The following data fields:- Intensity Factor (IF) and Training Stress Score (TSS) depend on the FTP value as would the %FTP data field.

Have to admit, it's pretty cool that the 520 can get FTP automatically without doing a FTP test and it is pretty close (2 cases so far). My old 500 and 510 had a default of 200 watts and my friend would always tell me to take the FTP test to find out what mine was. One of these days, I'll do the test again. I am just a wuss nowadays ;).

Basicly it must take your best 20 min. effort and calculate your FTP from that ( best20min = 0.95 % of FTP).... If using power as a serious training tool, you must do a reel FTP test "from time to time" in order to train according to actual FTP.

Basicly it must take your best 20 min. effort and calculate your FTP from that ( best20min = 0.95 % of FTP).... If using power as a serious training tool, you must do a reel FTP test "from time to time" in order to train according to actual FTP.

It's unnecessary to do a 'real' FTP test whatever that is as long as the test you choose is consistent. Makes no real difference for training.

It's quite possible the 520 takes your peak power at a few different time periods and then calculates FTP based on the relationship between critical power (CP) and anaerobic work capacity (AWC). Google Monod and Scherrer's critical power model if interested.

Thanks, my point was , that just one test 2 years ago isn't the best reference point for training today.

Thanks, my point was , that just one test 2 years ago isn't the best reference point for training today.

Oh I agree with you. It's like doing a max heart rate test...very painful. Also debatable whether one actually goes hard enough to hit that max HR. IMO it's debatable whether one hits their FTP due to road/weather/etc conditions. It's very difficult to find a stretch of road to ride a continuous hard all out 20 minutes. The best I could find was a bike trail 4 miles out and back, but that meant I had to slow down and do a U-turn. I had to do it early enough to avoid other bikes and runners. Slight wind made the ride completely different depending on the direction. FTP on my trainer was not the same as on the road. I seem to ride much harder on the road than on my trainer.

What I discovered though (just like after my years of running) is that I know my 'effort' levels for certain workouts and I don't necessarily need the power meter to tell me. Whether I lost some fitness or gained fitness, I can go through workouts and adjust the power levels based on how I feel at the time. I do find the PM very important when doing long rides and I'm trying to keep a somewhat constant power level (up hills, wind, road conditions). One last point is how valuable the FTP test is on what type of bike...road bike or tri bike. I ride very differently on my tri bike than road bike.

Oh I agree with you. It's like doing a max heart rate test...very painful. Also debatable whether one actually goes hard enough to hit that max HR. IMO it's debatable whether one hits their FTP due to road/weather/etc conditions. It's very difficult to find a stretch of road to ride a continuous hard all out 20 minutes. The best I could find was a bike trail 4 miles out and back, but that meant I had to slow down and do a U-turn. I had to do it early enough to avoid other bikes and runners. Slight wind made the ride completely different depending on the direction. FTP on my trainer was not the same as on the road. I seem to ride much harder on the road than on my trainer.

What I discovered though (just like after my years of running) is that I know my 'effort' levels for certain workouts and I don't necessarily need the power meter to tell me. Whether I lost some fitness or gained fitness, I can go through workouts and adjust the power levels based on how I feel at the time. I do find the PM very important when doing long rides and I'm trying to keep a somewhat constant power level (up hills, wind, road conditions). One last point is how valuable the FTP test is on what type of bike...road bike or tri bike. I ride very differently on my tri bike than road bike.

Your last sentence is right on the money. All my power based rides have been indoors for training purposes and on a Tri-bike where I religiously ride to power. This has made my racing faster as I know by both feel and power when I'm over doing it or not pushing hard enough. I just put a power meter on my cross/road bike and the power meter, I wouldn't say is useless, but the power levels look completely different. Power on a 60-75 mile grand Fondo looks nothing like power on a 40k time trial or Tri.

520 reset my FTP

I've been using my 520 regularly for about the 2 weeks I've had it and manually set the FTP to what I had before (incorrect or not). Then yesterday on a century ride, the 520 *RESET* my FTP to something incredibly low!!! It was set lower than my max 20 minute power for the 6 hour ride. That sure messed up all the metrics. Good thing I don't care about most of them.