FTP test versus Garmin's auto FTP

[Mamil]

So encouraged by my recent run of good fortune in managing to keep up with my group for most of the race, well at least until the gradient hits about 7 or 8 percent and when I am dropped being lucky enough on 2 separate occasions to find a little batch of people prepared to help and be helped back onto the main group and also using the fact that I managed to save a small fortune on replacing a wheel on my car after my S.O. decided to take it onto the rocky verge of the road "to give the other car some room" (agent wanted 11k for the rim, insurance excess was 6k and my cousin found a steel knockoff to act as spare for 2k) as a justification for indulgent and possibly ill advised consumer behaviour.... I bought myself another little cycling pressie ....

 

a Stages power meter.

 

LBS matched CW price (love them so much, the LBS that is) and fitted it this morning. I did 100 watts for 6 minutes in my school uniform and nearly crashed into a parked car because I was staring at my head unit. 

 

So now I need to do an FTP test. I don't have an IDT, a mate has said I can come over and hook my bike up to his Wahoo Kickr but I wanted to find out ....

 

How have other mamils determined their FTP? If on the road in CT, where? Needing a long stretch of flat or inclined road with no interruptions to do a max effort 20min stretch isn't as easy as it seems at first.

Do I understand that Garmin and Training peaks will automatically take your best 20min efforts over a period of time and automatically give you an FTP value and power zones, like they do with heart rate.

Are these reliable and valid enough to use as a basis for power based training?

Edited February 20, 2019 by Mamil

[Jehosefat]

I do my FTP tests on a smart IDT (CycleOps Hammer) and I have a power meter on my road bike. My Garmin occasionally suggests that my FTP has changed based on a road ride but usually only by about 2-4 W so I think it's accurate enough to just do your normal riding and let Garmin figure out your FTP rather than doing an actual FTP test. (Obviously assuming you go hard while you ride normally, it's not gonna work so well if you are just doing LSD rides)

Edited February 20, 2019 by Jehosefat

[DieselnDust]

The auto calculation for FTP in the garmin head units gives me a lower power value.

The Xert app (from iq store) is more accurate to the value given in a 20min test.

But the auto calculate apps will change your FTP on every ride which is frustrating. So only activate it when you want to see if it has improved I. E. At the end of a training block.

 

Have fun. It's addictive

[The Ouzo]

nothing to do with FTP, sorry I cant help you on that.

 

But regarding the aftermarket replica wheel, please make sure it is of decent quality, you dont want a cheap wheel coming apart on you SOs car, it could be very disastrous.

[bertusras]

Some reading

[Mamil]

Great responses. Thanks all.

 

Xert looks like a great place to start and will be on my garmin for tomorrow's ride. Must just remind myself to let it take care of itself and not keep pressing the light button to see what it's doing...

 

The rim is good and my cousin is a pro mechanic so I trust that it's good - going to use it as the spare of course and what really stung is that it was my car not hers!!

 

 

 

 

 

I do my FTP tests on a smart IDT (CycleOps Hammer) and I have a power meter on my road bike. My Garmin occasionally suggests that my FTP has changed based on a road ride but usually only by about 2-4 W so I think it's accurate enough to just do your normal riding and let Garmin figure out your FTP rather than doing an actual FTP test. (Obviously assuming you go hard while you ride normally, it's not gonna work so well if you are just doing LSD rides)

 

 

 

The auto calculation for FTP in the garmin head units gives me a lower power value.
The Xert app (from iq store) is more accurate to the value given in a 20min test.
But the auto calculate apps will change your FTP on every ride which is frustrating. So only activate it when you want to see if it has improved I. E. At the end of a training block.

Have fun. It's addictive

 

 

nothing to do with FTP, sorry I cant help you on that.

 

But regarding the aftermarket replica wheel, please make sure it is of decent quality, you dont want a cheap wheel coming apart on you SOs car, it could be very disastrous.

 

 

Some reading

[dsw]

The best place on in Cape Town that I know of to do a proper FTP test (on the road) is on the West coast road… the stretch past Melkbos and Duynefontein going towards Atlantis is fairly flat and interrupted for a 20 min effort.

 

I have had plenty of FTP tests done in the lab, on trainers and on the road and the results seemed inconsistent depending on where you do it. The figure in the lab was the highest but perhaps it is because I was more motivated in order to impress the sport scientist who was looking over my shoulder 

 

Nowadays I determine mine by doing an 8 minutes flat out effort on a flat stretch on the Bottelary road and then subtract 10% from the average power. Less hassle and probably not too far off the mark.

[MDJ]

Congrats on the purchase

 

I've had a Stages power meter for while, its only one sided though - still bugs me not knowing what the other leg is REALLY doing 

 

If you are a numbers person a PM takes so much guessing out of training and I prefer riding in the outdoors vs the IDT anyday! Its also nice to see real power on Strava after a ride vs. guessing which is messed up by bunch riding. I also find it pretty cool to look down in a race and know when I should probably pull back on a climb or if I'm probably going to get dropped because I'm pushing 300W for too long.

 

In terms of FTP tracking and analysis I really love David Tinker's tool: https://intervals.icu

 

Its super simple just point it at your Strava profile and voila. What I like is that its more than just an FTP test number - you get a full power profile over multiple metrics, TSS etc, much better than a Garmin magic number. It may not be as accurate as finding a isolated road with no traffic/interruptions to do a proper tests - but to me improvement is what I'm looking at and that is more relative v.s an absolute number. In terms of a theoretical test I find an IDT is the best.

 

Some reading I found useful:

 

https://www.bikehub.co.za/features/_/articles/training-nutrition/monitoring-your-training-load-r7477

Edited February 20, 2019 by MDJ

[Frosty]

Is the racetrack (Killarney) an option?

 

As a Vaalie, I wouldn’t know.

 

 

Sent from my iPhone using Tapatalk

[lechatnoir]

intervals.icu will become your new best friend alongside strava (Thanks David Tinker)

 

install XERT on your garmin - IIRC, you have a 935 which can run it. then read this... https://www.dcrainmaker.com/2017/07/xert-rolls-out-free-real-time-ftp-app-on-garmin-devices.html

 

and that's the beginning as FTP's just a number - you need to train against that for proper benefit... looking forward to you dropping even more often now! 

[lechatnoir]

Is the racetrack (Killarney) an option?

 

As a Vaalie, I wouldn’t know.

 

 

Sent from my iPhone using Tapatalk

 

it IS an option on some weekday evenings. personally, it'd be a hateful place to do an FTP test though. or perhaps i'm just k@k at FTP tests

[Tomik]

An FTP test is best done on a slight incline so Blouberg road not the best. It's harder to sustain power on the flats than on a slight gradient where the benefit from inertia is less.

 

A good place is from the lights at the end of Camps Bay to the top of Suikers. That starts flat and then is a slight incline ending with a bit of a steeper section where you can give it your best. It's between 17 and 20 min usually. Took me 17:30 at 260w last week. Or 18min at 270w with a bit of a headwind the week before. Those are on a group ride so solo will take a bit longer.

[LongDonkey]

My Kickr values versus the FTP pushed out by the Garmin unit are not aligned on the MTB (as an aside). Its upwards of 20 W higher on the Garmin unit which is not really believable. So i make sure to not update the Garmin FTP to my Kickr training software. MTB is not ideal i know, but it is interesting.

 

Seeing as i assume you are doing the CTCT, that is a perfect opportunity to put in some efforts on blue route through to Smitswinkel at the front of the peloton to get 20 mins Mamil effort......... 

[davidtinker]

I haven't tried "Camps Bay to the top of Suikers" for a long effort, thats a good tip.

 

You can get pretty good estimates from your best 5 second power, 3 min power and 10+ min power. It's easier to get good numbers for these than to do a 20m test. You don't need to do them all on the same ride.

 

Thats how Intervals.icu estimates FTP using Morton's 3 parameter critical power model.

[Mamil]

Friday being my admin day or skiving off day I dropped the progeny at school, parked the car around the corner, took the bike off the roof and did a 30k warmup to Camps Bay. Xert on the Garmin, banana smoothie with wheat germ and peanut butter in the petrol tank and that funny feeling I get whenever anything with the word "test" in it is on my horizon.

 

Survived the murderous traffic, the motor car being the primary mechanism of discharge for the aggression and anxiety that besets our society so thoroughly these days, and noticed the games my head was playing with me "Ooo your legs are feeling a bit weak today" and "Shouldn't be breathing so heavily standing up over the little bridge next to the bakery" .... "Throats a little dry, maybe the offpring's tonsillitis is breeding in there"

 

Shut up legs ---- more like shut up head.

 

Got to Camps bay, took a manly swig of my water bottle, straightened my helmet, put xert on the screen, pulled my PPA "stay wider of the wide rider" lycra over my waist, and resolved to put down more watts than a dodgy Eskom generator can deliver.

 

Mamil versus mountain. 

 

20 seconds later I was in oxygen debt because I took off far too fast, told myself to calm the F#@#% down and settled into an uncomfortable rhythm. 

 

By the time I got to the bend before Llandudno I was over it - snot attractively caught in my beard, nausea threatening to recycle the smoothie, legs burning. At the Llandudno robots I bargained with them to change to red but they didn't .... the Xert field swimming in front of my eyes but still going up ...  I overtook a couple on MTBs "Take it easy" said one -- I couldn't say anything .... got to the top and ended the pain.

 

The result - well ... if I had both arms and a leg amputated I could ride the world tour at 6 watts/kg. 

 

And it told me what I kinda knew - lose 5 or 6 kg and you'll be a much faster cyclist.

 

Thanks for all the help and the camps bay to suikerbossie tip.

 

18:30 at 332 watts with a very slight headwind.

Edited February 22, 2019 by Mamil

[Dubber]

Cool.  Now you know what your FTP is.  What you going to do with it?

 

Of course, if you test again in the future and its gone up, you probably a bit faster.  But the real trick is to use this number to train with.

 

Lots of info on the web how to train using your specific ftp and power.  Try use it - otherwise it's just another number.

 

Good luck!