Watts not equating to speed

[thenortherner]

Whilst the weather's crap and in an attempt at increasing FTP I've been doing some harder interval sessions for an hour.

I'm using a Kickr Core and have performed the spin up / spin down to calibrate the power but it seems to make no odds to the results. And I'm using my Garmin 810 to record the sessions.

Anyhow, the weighted power or power recorded doesn't seem to equate to what I'd expect in terms of speed/distance. Below's an example. I've seen lots of others producing similar watts on the turbo but averaging much better speeds and distance.

Does this look right to you?

Unrelated but I've done zero exercise for 4 years - I lost motivation after an Ironman in 2016 - and hadn't touched my bike until the first week of August. For an hour's output is this a reasonable average wattage?

[CourtAgain]

I can't see Watt the issue is...

[sociopath]

I run a different system (wattbike and fulgaz) which takes into account rider weight, but to me that looks a not unreasonable set of figures.

I'd generally be producing about 200 watts and averaging about 16mph on a flat ride, which equates to what I do IRL

[defblade]

thenortherner said:

I've seen lots of others producing similar watts on the turbo but averaging much better speeds and distance.

Lots of others might well be, let's say charitably, "blueprinting" their assumptions and figures (not least their weight ) in order to make their results look better when posted and hence bump their ego, if not their abilities.

At the end of the day, everyone's equipment, power meters etc will be different even if figures haven't been #cough# optimised #cough# , and so despite Zwift racing and similar stuff, it's not easy to directly compare figures for 2 different set-ups.

So long as you keep riding the same kit, you will build your own results to see improvements. You know when you're working hard (or not!)

That's why I quite like Zwift's workouts, for all the faults people pick with them - they use your FTP as recorded by Zwift and so they scale to your fitness as measured on your kit. Who cares if you'd be "higher" or "lower" on another set up?

[thenortherner]

Thanks. I'm not sure what's calculating the speed/distance - presuming it's the Garmin - if so, my Garmin scales record my weight so maybe it's using this. I weigh 12st 10.

Only questioned as I've seen lots of others on Strava produce similar power but producing a much higher speeds/distance and I'm pretty sure I weigh less than they do.

[thenortherner]

defblade said:

Lots of others might well be, let's say charitably, "blueprinting" their assumptions and figures (not least their weight ) in order to make their results look better when posted and hence bump their ego, if not their abilities.

At the end of the day, everyone's equipment, power meters etc will be different even if figures haven't been #cough# optimised #cough# , and so despite Zwift racing and similar stuff, it's not easy to directly compare figures for 2 different set-ups.

So long as you keep riding the same kit, you will build your own results to see improvements. You know when you're working hard (or not!)

That's why I quite like Zwift's workouts, for all the faults people pick with them - they use your FTP as recorded by Zwift and so they scale to your fitness as measured on your kit. Who cares if you'd be "higher" or "lower" on another set up?

I don't know why people try to bullst their results. Surely they'll only get caught up when riding on the road and can't quite live up to their turbo numbers?

I'm confident that if I put the same perceived effort in on a flat, decent surface for an hour I'd be averaging a lot more than 17.5 mph.

[lufbramatt]

Distance/speed is irrelevant indoors. Just worry about time at a given power. Could try changing into a higher gear so the back wheel is spinning faster.

My turbo sessions are similar- the average "speed" is lower than what I would do outside for the same average power, but it's the power that matters. quite funny when you see people boasting of doing "indoor gran fondos" in sub 3 hours with a power output of about 150watts when you know they would struggle to do much over 16 mph in real life.

Edited by lufbramatt on Friday 30th October 22:52

[gl20]

On a related topic it’s only recently I’ve noticed that I’m far further down the Strava segment rankings on Zwift than I’m outdoors. I’m a below average club rider but might typically be around top 40% in any given outdoor segment. I’ll look at the KOM and realise I’ll get close to them, but they do at least seem possible.

Then I look at zwift segments and simply can’t believe how the KOM (On an example I saw this week) can be 3 times faster than me and a minute quicker than the third fastest person (Equating to a 30% difference). What of the second fastest person? Well ‘She’ was just 1 second slower than he was. I hear there are people who set up powered rigs to achieve these times but just not sure what the point is?

[Paul Drawmer]

As a sensibility check - what power output do you get if you're doing 15mph? This should be the same for everybody surely?

If I just pedal at 15mph on my Cycleops Magnus it returns near enough 150watt according to Wahoo fitness app.

[oddball1313]

I really wouldn't get hung up on other riders figures on Zwift, I'll wager a good percentage are entering lower body weights to artificially increase their power, some by just a few Kg and some by ridiculous figures. I was on an interval session the other night and saw some dhead go past me pushing 15.8w/kg
Some of the KOM are laughable, I don't know how the algorithums don't spot them - I saw some fat little arab guy the other week with a claimed FTP of over 550w and a 29.5mph average.

[defblade]

oddball1313 said:

I was on an interval session the other night and saw some dhead go past me pushing 15.8w/kg

I can, at the right moment, hit 14w/kg for a couple of seconds, and over 10w/kg for 10 secs, and I'm not any sort of trained/quick/powerful/pro rider, so 15.8 for a short while should be well in the realms of reasonable for many people, especially in sprint workouts.
What you might not notice is the 3 minutes of 1.2-1.5w/kg I then have to do to stop panting like an asthmatic overheated dog afterwards!!!!

[oddball1313]

defblade said:

I can, at the right moment, hit 14w/kg for a couple of seconds, and over 10w/kg for 10 secs, and I'm not any sort of trained/quick/powerful/pro rider, so 15.8 for a short while should be well in the realms of reasonable for many people, especially in sprint workouts.
What you might not notice is the 3 minutes of 1.2-1.5w/kg I then have to do to stop panting like an asthmatic overheated dog afterwards!!!!

This dude was holding it down for more than 10 seconds, he may as well have been riding a Kawasaki. You’re talking well over 1000 watts, most people can’t hit that ever, even for 5 seconds.

[lufbramatt]

Paul Drawmer said:

As a sensibility check - what power output do you get if you're doing 15mph? This should be the same for everybody surely?

If I just pedal at 15mph on my Cycleops Magnus it returns near enough 150watt according to Wahoo fitness app.

Had a look out of interest, using a kinetic road machine, tyre at 100psi, 2 1/2 turns of pressure on the roller: 150 Watts = 14.3mph

But that’s just how I set it up for consistency between my training sessions, i could set it up looser and get more “miles” if I was fussed.

[Ares]

I'm not a specialist, but Zwift won't be 100%, but it's not monumentally far off in my experience.

If you had a wind-free, zero-friction ride, speeds wouldn't be crazily different.

Back on topic.... Watts/Speed will depend on your weight. Your power is good, but if you are 100kg, it's only just over 2w/kg.

Stats are pretty much incomparable, but you can track one against another over time.

If I look at a couple of recent Zwift sessions (top two were group rides, bottom one was solo), and I'm a smidge over 60kg, so at 180w I'm at 3w/kg, 240w I'm 4w/kg:






Compare that to real life (all solo)....

[okgo]

It looks too slow to me also.

220w on the flat should be giving you a fair bit more than that. Just had a look at a zwift I did just now, first 15 mins were flat, avg 237w and avg 22.5mph. Similar weight to you. That was with a quarq.

[Coolbananas]

I have a Kickr Core but only used it for a couple of weeks earlier in the year (on Zwift) and didn't feel it was very far off my 'real World' numbers when compared to Strava guesstimates but it did seem to flatter me with higher averages despite accurate weight input. I much prefer to ride outside though so it has to be a really bad sequence of days to force me indoors.

The relative value in terms of speed expectations for the numbers the OP has depend upon many factors, surely, not least power-to-weight? I'm a relative noob to power meters actually, but now using a Stages 3 on one of my road bikes and still learning how to use it. I haven't done an FTP test since getting back into cycling, 18 months in now. The Stages does disagree with Strava guesstimates, especially for shorter segments which read higher than Stages gives me. Longer climbs are closer though.

What I have also learned is the difference between my approximate FTP vs Max Power is quite wide currently and something I have to work on - more so than most I ride with who I can comfortably beat in a sprint but struggle to hang with on climbs or match in time trials.

Currently my Power Curve on Garmin suggests my FTP is around 260 watts (doing the correct calculation from the raw 20 min figure it has picked up from the rides I've done lately but I've not gone flat out for 20 min 'deliberately' to see yet) and my Max recorded so far is 1081 watts with 5 sec at 1023 watts. I don't ride that bike all the time and I've only had the PM for a month so it'll be interesting to see how those numbers go up (hopefully, but my best numbers will have been 25 years ago, I'm 51 now and 3-4kg overweight for a cyclist my height at 65kg ).

[okgo]

Weight actually makes little odds on the flat, once up to speed anyway, especially when its virtual and drag isn't coming into it. I assume OP's ride was just a normal turbo ride not synced to something with hills in it given there's no elevation data.

Your max power will always be miles away from your FTP, so that's normal.

[Matt_N]

Looks a bit slow to me, depends on weight to an extent but as another comparison I just rode home from work, 210w weighted average from a PowerTap, 19.6mph avg, fair bit of stop start due to traffic lights and I’m on my commuter bike.

Edited by Matt_N on Monday 2nd November 20:14

[Centurion07]

Vaguely related...

does Strava do any kind of calculation to take into account all the other stuff like wind speed and direction, gradient, weight etc when giving you power figures or does it just calculate using distance and time?

[Ares]

Centurion07 said:

Vaguely related...

does Strava do any kind of calculation to take into account all the other stuff like wind speed and direction, gradient, weight etc when giving you power figures or does it just calculate using distance and time?

Assuming you are talking about real life (i.e., not from Zwift), if you have full sensors (HRM/Power/Cadence/speed/etc), it takes all the data it needs from there/those.

In the absence of those, Strava does take in account elevation (either via your GPS/OBC, or using it's own database if that isn't present). It doesn't factor in wind. Anything generated from Strava algorithms are fairly inaccurate with power, often showing double, or half actual power.