Mainly just for being nosey on Strava… is there a way to calculate FTP from max power on a ramp test?
TR uses 0.75 x Best 1-Minute Power
Cool, I tested this on my own ramp test and it had my FTP at 10 more than what it was… I guess that’s as accurate as I’ll get from just looking at max power? I guess it depends on how long that max power was held for too.
It’s not single max power for the workout. It’s the best 1-minute duration of power. So, you need to find a full minute with the highest average power over that minute.
It will be close but different dependent on you and what you are good at???
Yes TR uses 0.75 and it is good for me … I have close corallation to the 0.75 but … can be different dependent on what you are trying to achieve?
What he seems to be trying to achieve is to reverse figure the FTP of a competitor via Strava Stalking
So the finer details (and utter mess) of Ramp Tests and FTP values may not apply here?
My wife has just given me a shout ??
Its bed time in Scotland
That is what I was thinking. And if its a different ramp test protocol (different step durations, different step sizes) the multiplier would be different.
Goodnight dear friends
Yup, sure could be. I went with the simple context of someone asking on a TR forum and gave the TR answer. Anything else could be different.
The .75 x best minute is correct, but there’s an adjustment if you go significantly over target for the last minute- by sprinting towards the end, for instance. That’ll drive the actual minute power up but the calculation ignores those surges, so if you’re trying to snoop someone’s FTP off Strava, beware of any late-ramp test sprints that might skew your self-calculated results.
If you really want to be an FTP creeper, just wait till they do a workout, then look at the workout analysis and see what the % FTP is prescribed for an interval. If someone is doing 200w on an 80% interval, 200 / .8 = FTP 250w
Or if they have their FTP set in Strava already then you can go to the ‘zone distribution’ tab and under the ‘Threshold’ bucket the FTP will be about 2/3 of the way through that range.
For example, my ftp is set at 295W.
Everyone knows that married men cannot sustain a high TSS score because they are not used to that kind of work, but teens can maintain a high TSS (watch for saddle sores)
Some married men try to find extra TSS in other activities but that usually leads to a total collapse of the entire plan
On Strava, you can go to the “Zone Distribution” page on a rider’s activity page (if they’re a subscriber), and divide the weighted average power by their intensity. This gives you a number within a couple watts of their FTP. Attached is mine. 223/.81 = 275 when my FTP is set to 274.
What I do is take the lower vo2max number (288-328) and divide by 1.05, so 288/1.05 = 274.
And it assumes that person updates their FTP. I’ve seen plenty of inaccurate FTPs, and don’t always update mine on Strava.
That works well if they are doing a TrainerRoad workout.
I’ve got a suggestion here, for the general Trainerroad dev team…rather than taking 0.75 x last minute power, a more robust measure will be average power over last  minutes, as it will get rid of estimation noise, and the effects of accelerating at the end which will give a falsely high FTP.
pps this is why I think that the ramp test works…the 0.75*last_minute_power is approximately the same as the 12 minute average, for 13 watt step size (which is 5% of FTP for a FTP of 260). The ramp test window is in the middle of the 8 minute and 20 minute windows, but doesnt require you to know where to aim with your effort.