Using speed instead of power?

Gav888

Hi,

Ok, ive been reading up on power, and training etc today and ive come up with a possible work around that may or may not work, so im posting it hear to gather your thoughts.

At the moment I only have a hrm and sadly no plans this year to buy a power meter, but I still want a way of making sure im using the right intensity when doing interval training.

At the moment if im doing a 60min hr zone 3 tempo workout on the turbo, its taking approx 15min to get my heart rate into zone 3, so until its there I cannot judge how hard I should be pedalling. That 15min could be too high, or too low which is why its taking ages to get to zone 3, also for vo2max intervals, you cannot use heart rate as these are normally 4 - 6min long and heart rate is too slow. From my understanding heart rate is good for long rides, say 30min or longer but short intervals power is best.

So ive been thinking that the power community refer to levels as CP3, CP6, CP12, CP20, CP30, CP60, CP90 etc, and CP60 being your FTP.

So, my understanding (please correct me if im wrong) is CP60 is the highest power output you can maintain for 60min, and CP20 is the same but for 20min, CP3 is 3min and so on. If thats the case, if I ride max effort for 60min and record my average speed that speed would effectively be my CP60 speed, of FTS - Functional Threshold Speed?

Obviously this would only work on an indoor turbo training or rollers as there are too many variables outside to use speed, hills, wind, etc etc but when using a turbo it should be a good estimate shouldnt it?

If so, I could then use power zones, such as these http://www.trainingbible.com/joesblo...ing-zones.html replacing the power at CP60, with my average speed to work out approx speeds to achieve for each level of effort. Then when I do say a 20min interval I make sure im going at my CP20 speed?

With regular CP60 tests I could monitor my new speeds as I get fitter?

Does this sound right?

Bronzie

On the turbo, rear wheel speed as a proxy for power can work fairly well. You soon get to suss out what speed you can do 2x20's at etc and track improvement as you get fitter.

The big proviso is making the conditions repeatable each time - it's best if you can leave an old frame set up on the turbo rather than keep setting your road bike up on the turbo (assuming you are also using it outdoors at weekend). You also need to make sure your tyre pressure is consistent.

There are a few problems though:
- if you change any of the conditions (roller pressure on tyre or rolling resistance with a new tyre) you have to work out your "zones" from scratch - you may be able to use a "roll-down test" to try to calibrate things (timing how long the wheel takes to stop from a known speed)
- ambient temperature (and hence rolling resistance) can be hard to account for
- it's very difficult to relate "levels" to each other - a 10% increase in speed may not equal a 10% increase in power

chrisw12

Gav, it seems like a good idea and in theory, everything you say is possible, just in practice, using speed as a proxy has too many problems. For example, there was a thread on here not too long ago where someone was trying to compare their speed (on turbo) last year with now and he got some horribly confusing results.

I had the same problem as you this time last year. I wanted to do intervals in a controllable way and use them to measure progress. I though about it and tried going down the turbo route but ended up instead using a local road with no stops and doing loops of that for long intervals and using a short hill for short intervals. I was flexible with my training days so that I could do my key intervals when the weather was good. Then when I'd had a guts full of the wind messing up the results I'd saved enough credits to buy a power meter.

You seem keen to get a good structured training plan with a bit of accuracy thrown in, at the end of the day if these are your aims then bite the bullet and either get or save up for a powermeter. Honestly it's worth the investment and takes out a lot of the questions you are asking. Not that there's anything wrong with your questions.

Edwin

Yep, maybe better than not structuring anything at all, but agree it's worth getting a powemeter eventually if you're that serious. It doesn't have to be that expensive either, you can rent one or look around second-hand, I bought a ready built wheel with an Open Pro rim around a Powertap comp for 300 quid including the head unit. The only problem was the previous owner's dog had chewed the USB lead on the cradle that connects to the PC, but I fixed that for free with some leccy tape! I'm a bit of a geek, so I like being able to load everything on to a laptop and see some numbers, I've found it's motivating me a lot, whereas on the road you can go as hard as possible and have little idea if you're improving or not. I don't think I could train on a turbo without at least knowing I'm generating some vaguely useful data.

BeaconRuth

chrisw12 wrote:

You seem keen to get a good structured training plan with a bit of accuracy thrown in, at the end of the day if these are your aims then bite the bullet and either get or save up for a powermeter.

Chris, you seem to be suggesting that it's not possible to do well-structured training without a powermeter. If you are then can I just say that that's utter rubbish? There are ways of measuring your workload and progress objectively (and accurately enough for most people's needs) which don't involve using a powermeter. (Or (this is below the belt ) perhaps you think I wasn't doing effective, structured training the year I beat you by 25mins in the Welsh 100 and broke the Welsh comp record?)

Bronzie's advice is good. What it comes down to is finding at which speed you can do the various sessions for the different zones you're targetting. Use your HRM to judge whether you're under or overcooking it, by experience. If you do a training session 5 times at the same speed and each time your HR ends up higher than it should, then you've obviously chosen a speed that's too high. That's all there is to it.

Ruth

jibberjim

Gav888 wrote:

If so, I could then use power zones, such as these http://www.trainingbible.com/joesblo...ing-zones.html replacing the power at CP60, with my average speed to work out approx speeds to achieve for each level of effort. Then when I do say a 20min interval I make sure im going at my CP20 speed?

As others have said, there's no problem with using speed as a proxy for power, many turbo manufacturers even publish the power curves of their trainers, but as others have also said it's sensitive to set up and tyre pressures.

Your biggest likely problem is in finding the relevant speeds that aren't your tested CS 60, since the speed will differ by a different amount than power does. i.e. 10% slower speed might be 95% of the power and 30% of the speed 65% of the power. ie the turbo has a curve, not a linear relationship.

Testing and training is better than just random testing and the simple rewards of seeing a number increase will likely help you more than anything else.

Gav888

Thanks for the advise guys, ive done quite a bit of zone 2 and zone 3 sessions so far on the turbo this year and end of last year so ive got a good idea of what speed I can do for those zones, and using the percentages from Joe Friels power zones I can work out the speeds for each zone, and for zone 2, 3 and 4 they work out fairly accurately with what I can do. At the end of the day its giving me an idea of what I can do without having a powermeter and also when heart rate cannot be used.

Conditions are generally the same, the only thing that wouldnt be is a few degrees temperate difference between winter and summer, I use the same bike, check the tire pressures every other session, fan is set to the same speed each time, and the turbo is a Elite Crono Fluid so resistance is via the gears on the bike. Say that, ive just remembered there is a small plug on the side of the resistance hub that you can plug something in, do these turbo's have an optional power meter?

I will keep an eye out for a 2nd hand power meter, didnt think of that, but I feel I will need one sooner or later as I do like looking at data

amaferanga

Gav888 wrote:

Thanks for the advise guys, ive done quite a bit of zone 2 and zone 3 sessions so far on the turbo this year and end of last year so ive got a good idea of what speed I can do for those zones, and using the percentages from Joe Friels power zones I can work out the speeds for each zone, and for zone 2, 3 and 4 they work out fairly accurately with what I can do. At the end of the day its giving me an idea of what I can do without having a powermeter and also when heart rate cannot be used.

Conditions are generally the same, the only thing that wouldnt be is a few degrees temperate difference between winter and summer, I use the same bike, check the tire pressures every other session, fan is set to the same speed each time, and the turbo is a Elite Crono Fluid so resistance is via the gears on the bike. Say that, ive just remembered there is a small plug on the side of the resistance hub that you can plug something in, do these turbo's have an optional power meter?

I will keep an eye out for a 2nd hand power meter, didnt think of that, but I feel I will need one sooner or later as I do like looking at data

You've got the same turbo as me, only mine is the digital version with a head unit that displays speed, distance and something they call power. I'll have a powertap soon so I'll know for sure, but I think the resistance varies quite a bit with temperature (mine is in the garage).

chrisw12

BeaconRuth wrote:

chrisw12 wrote:

You seem keen to get a good structured training plan with a bit of accuracy thrown in, at the end of the day if these are your aims then bite the bullet and either get or save up for a powermeter.

Chris, you seem to be suggesting that it's not possible to do well-structured training without a powermeter. If you are then can I just say that that's utter rubbish? There are ways of measuring your workload and progress objectively (and accurately enough for most people's needs) which don't involve using a powermeter. (Or (this is below the belt ) perhaps you think I wasn't doing effective, structured training the year I beat you by 25mins in the Welsh 100 and broke the Welsh comp record?)

Bronzie's advice is good. What it comes down to is finding at which speed you can do the various sessions for the different zones you're targetting. Use your HRM to judge whether you're under or overcooking it, by experience. If you do a training session 5 times at the same speed and each time your HR ends up higher than it should, then you've obviously chosen a speed that's too high. That's all there is to it.

Ruth

No I'm not suggesting that. I'm suggesting that if you keep on asking questions about using speed as a proxy for power then eventually you'd be be better off 'biting the bullet' and buying a power meter.



Don't want to make excuses but that race brings back memories. Don't want to lay a guilt trip on you but iirc that race was two weeks after I came out of hospital after a lung operation.

In that year I'd had two minor strokes and two lung collapses (not good when you're in your early 30's with two great, young children). That operation cured the lungs and I cured the stroke problem. That was the last time I've been to hospital and that race was the end and start of a new life phase for me. Happy memories for me finishing and you battling my club mate. I've got a tear in my eye now.... :oops:


and Welsh 12hr is in July this year if you fancy it? Don't think I'll be up for the 100 after it tbh.

BeaconRuth

chrisw12 wrote:

Don't want to make excuses but that race brings back memories. Don't want to lay a guilt trip on you but iirc that race was two weeks after I came out of hospital after a lung operation.

In that year I'd had two minor strokes and two lung collapses (not good when you're in your early 30's with two great, young children). That operation cured the lungs and I cured the stroke problem. That was the last time I've been to hospital and that race was the end and start of a new life phase for me. Happy memories for me finishing and you battling my club mate. I've got a tear in my eye now.... :oops:

In which case, my sincere apologies for mentioning it in the manner I did. Just goes to show that you don't know what battles and achievements other people are experiencing. It's a few years ago now - many congratulations on getting your health back. Good health is way way more important than winning races or doing fast TTs.

and Welsh 12hr is in July this year if you fancy it? Don't think I'll be up for the 100 after it tbh.

Sounds like it's close to the National 100........... not that I'd think of riding a 12 anyway!

Ruth

Gav888

amaferanga wrote:

Gav888 wrote:

Thanks for the advise guys, ive done quite a bit of zone 2 and zone 3 sessions so far on the turbo this year and end of last year so ive got a good idea of what speed I can do for those zones, and using the percentages from Joe Friels power zones I can work out the speeds for each zone, and for zone 2, 3 and 4 they work out fairly accurately with what I can do. At the end of the day its giving me an idea of what I can do without having a powermeter and also when heart rate cannot be used.

Conditions are generally the same, the only thing that wouldnt be is a few degrees temperate difference between winter and summer, I use the same bike, check the tire pressures every other session, fan is set to the same speed each time, and the turbo is a Elite Crono Fluid so resistance is via the gears on the bike. Say that, ive just remembered there is a small plug on the side of the resistance hub that you can plug something in, do these turbo's have an optional power meter?

I will keep an eye out for a 2nd hand power meter, didnt think of that, but I feel I will need one sooner or later as I do like looking at data

You've got the same turbo as me, only mine is the digital version with a head unit that displays speed, distance and something they call power. I'll have a powertap soon so I'll know for sure, but I think the resistance varies quite a bit with temperature (mine is in the garage).

Interesting... once you have the powertab it would be interesting to compare the data from the turbo to see how accurate it is....

Gav888

chrisw12 wrote:

I'm suggesting that if you keep on asking questions about using speed as a proxy for power then eventually you'd be be better off 'biting the bullet' and buying a power meter.

Sorry, I did ask about this a while ago but back then I had little knowledge of training and I didnt have a turbo. Now I have a turbo and although speed isn't power it gives me a rough idea of what speed to hold for a specifc zone / period / interval.

chrisw12

BeaconRuth wrote:

chrisw12 wrote:

Don't want to make excuses but that race brings back memories. Don't want to lay a guilt trip on you but iirc that race was two weeks after I came out of hospital after a lung operation.

In that year I'd had two minor strokes and two lung collapses (not good when you're in your early 30's with two great, young children). That operation cured the lungs and I cured the stroke problem. That was the last time I've been to hospital and that race was the end and start of a new life phase for me. Happy memories for me finishing and you battling my club mate. I've got a tear in my eye now.... :oops:

In which case, my sincere apologies for mentioning it in the manner I did. Just goes to show that you don't know what battles and achievements other people are experiencing. It's a few years ago now - many congratulations on getting your health back. Good health is way way more important than winning races or doing fast TTs.

and Welsh 12hr is in July this year if you fancy it? Don't think I'll be up for the 100 after it tbh.

Sounds like it's close to the National 100........... not that I'd think of riding a 12 anyway!

Ruth

No offence caused at all . As I said, very happy memories of that race. We went on to win the Welsh team bar that year, that was an achievement as the other two had to pull me along. Also really started my love affair with long distance tt 'ing.

Besides every defeat is an inspiration to train harder and it's good to be reminded when you're soundly beaten by a girl.

chrisw12

Gav888 wrote:

chrisw12 wrote:

I'm suggesting that if you keep on asking questions about using speed as a proxy for power then eventually you'd be be better off 'biting the bullet' and buying a power meter.

Sorry, I did ask about this a while ago but back then I had little knowledge of training and I didnt have a turbo. Now I have a turbo and although speed isn't power it gives me a rough idea of what speed to hold for a specifc zone / period / interval.

and Gav; I have no problem with you asking it and re asking it. It's a good question and if speed could be used as a reliable proxy for power like you suggest then it would save a lot of people a lot of money.

FFs, I've said that and I can't even remember what the question was now, I've got so much water in my eye.

Bronzie

Edwin wrote:

I don't think I could train on a turbo without at least knowing I'm generating some vaguely useful data.

I agree this is a massive plus point for having accurate power measurement on the turbo - it is VERY motivating to try and improve on last weeks power figures by just a few watts.

I used rear wheel speed only last winter and went from doing 2x20's at 19.0mph to 21.5mph over a period of about 10 weeks. I have an old bike that I keep setup on the turbo in the garage so apart from checking tyre pressure each time, nothing much changed between sessions apart from ambient temperature.

Gav888

Bronzie wrote:

Edwin wrote:

I don't think I could train on a turbo without at least knowing I'm generating some vaguely useful data.

I agree this is a massive plus point for having accurate power measurement on the turbo - it is VERY motivating to try and improve on last weeks power figures by just a few watts.

I used rear wheel speed only last winter and went from doing 2x20's at 19.0mph to 21.5mph over a period of about 10 weeks. I have an old bike that I keep setup on the turbo in the garage so apart from checking tyre pressure each time, nothing much changed between sessions apart from ambient temperature.

Thats interesting to see what speed you can do for 2 x 20's, it gives me something to aim for

reppohkcor

Gav888 wrote:

Bronzie wrote:

Edwin wrote:

I don't think I could train on a turbo without at least knowing I'm generating some vaguely useful data.

I agree this is a massive plus point for having accurate power measurement on the turbo - it is VERY motivating to try and improve on last weeks power figures by just a few watts.

I used rear wheel speed only last winter and went from doing 2x20's at 19.0mph to 21.5mph over a period of about 10 weeks. I have an old bike that I keep setup on the turbo in the garage so apart from checking tyre pressure each time, nothing much changed between sessions apart from ambient temperature.

Thats interesting to see what speed you can do for 2 x 20's, it gives me something to aim for

Just in case you weren't being sarcastic etc. 21.5mph on a turbo set up for someone else is completely different to road speed. 21.5mph on a turbo does not equal 21.5mph on the road (for what is's worth it's usually quite a bit higher on the road but thats besides the point) speed is completely different to power, here endeth the lesson.

oldwelshman

Bronzie wrote:

Edwin wrote:

I don't think I could train on a turbo without at least knowing I'm generating some vaguely useful data.

I agree this is a massive plus point for having accurate power measurement on the turbo - it is VERY motivating to try and improve on last weeks power figures by just a few watts.

I used rear wheel speed only last winter and went from doing 2x20's at 19.0mph to 21.5mph over a period of about 10 weeks. I have an old bike that I keep setup on the turbo in the garage so apart from checking tyre pressure each time, nothing much changed between sessions apart from ambient temperature.

But did it help you win races?
I have to be honest I find it very very difficult to get motivated to get my arse on a trubo, end even worse to do anything worthwhile when on it
I do howevr intend to bite the bullet and do simulated track sessions on it. Shorter harder intervals etc, 3km efforts etc.
I would go insane doing 20 x 20
How you guys manage this is beyond me

Alex_Simmons/RST

oldwelshman wrote:

But did it help you win races?

Helps me. Here's the gap for my crit win last weekend:

Gav888

Alex_Simmons/RST wrote:

oldwelshman wrote:

But did it help you win races?

Helps me. Here's the gap for my crit win last weekend:

Nice gap!!! well done, I take it the guy pulling off couldn't keep up

Reppohkcor, yep I was being sarcastic as I know speed on a turbo is different to the road, and speed is different from one turbo to another but its something to aim for

Jeff Jones

Nice one Alex! They'll be putting you up a grade ;-)

Slimbods

oldwelshman wrote:

Bronzie wrote:

you guys manage this is beyond me

iPlayer!

Toks

Alex_Simmons/RST wrote:

Here's the gap for my crit win last weekend:

Thats fantastic Alex! Well done mate - you are an inspiration. When are you gonna write winning race report for your blog? And it would be nice to see your power numbers too

Pokerface

Alex_Simmons/RST wrote:

oldwelshman wrote:

But did it help you win races?

Helps me. Here's the gap for my crit win last weekend:

Alex - is that a regular able-bodied crit? If so, makes it even more impressive!

oldwelshman

Alex_Simmons/RST wrote:

oldwelshman wrote:

But did it help you win races?

Helps me. Here's the gap for my crit win last weekend:

Well done
My question was specifically for Rich, not for everyone
Guess I will find out tomorrow when he is on the reliability ride.

Alex_Simmons/RST

Jeff Jones wrote:

Nice one Alex! They'll be putting you up a grade ;-)

Yes, I think so.

I attacked early on for about 4 laps but my partner wasn't able to contribute sufficiently to make it stick, so I just rolled with the group and waited, launching my attack over the second pimple into the NE wind (about 600 metres to go). They all just looked at each other thinking I was going way too early. I knew better given the wind on that day.

Jeff of course knows the circuit very well, and that is an attack just before the final technical part of the circuit leading onto the 400m long straight.

NP for the ~48min was 287W

Australia Day crit Tuesday, that won't be quite so "easy".

Alex_Simmons/RST

Pokerface wrote:

Alex - is that a regular able-bodied crit? If so, makes it even more impressive!

Yes, regular graded scratch crit at our local race circuit, Sydney's Heffron Park.

MatthewBulmer

Bronzie wrote:

Edwin wrote:

I don't think I could train on a turbo without at least knowing I'm generating some vaguely useful data.

I agree this is a massive plus point for having accurate power measurement on the turbo - it is VERY motivating to try and improve on last weeks power figures by just a few watts.

I used rear wheel speed only last winter and went from doing 2x20's at 19.0mph to 21.5mph over a period of about 10 weeks. I have an old bike that I keep setup on the turbo in the garage so apart from checking tyre pressure each time, nothing much changed between sessions apart from ambient temperature.

I think that this is the bottom line. If you can reduce the variables as much as possible (some very good ideas already given) then I think that you can use rear wheel speed on a turbo as ONE of the ways to HELP you gauge the intensity of your workouts (along with RPE and HR.) It has obviously nowhere near the accuracy of a power meter, but then if you can't afford a power meter then that's a moot point anyway.

amaferanga

Gav888 wrote:

amaferanga wrote:

Gav888 wrote:

Thanks for the advise guys, ive done quite a bit of zone 2 and zone 3 sessions so far on the turbo this year and end of last year so ive got a good idea of what speed I can do for those zones, and using the percentages from Joe Friels power zones I can work out the speeds for each zone, and for zone 2, 3 and 4 they work out fairly accurately with what I can do. At the end of the day its giving me an idea of what I can do without having a powermeter and also when heart rate cannot be used.

Conditions are generally the same, the only thing that wouldnt be is a few degrees temperate difference between winter and summer, I use the same bike, check the tire pressures every other session, fan is set to the same speed each time, and the turbo is a Elite Crono Fluid so resistance is via the gears on the bike. Say that, ive just remembered there is a small plug on the side of the resistance hub that you can plug something in, do these turbo's have an optional power meter?

I will keep an eye out for a 2nd hand power meter, didnt think of that, but I feel I will need one sooner or later as I do like looking at data

You've got the same turbo as me, only mine is the digital version with a head unit that displays speed, distance and something they call power. I'll have a powertap soon so I'll know for sure, but I think the resistance varies quite a bit with temperature (mine is in the garage).

Interesting... once you have the powertab it would be interesting to compare the data from the turbo to see how accurate it is....

I still don't have the powertap, but here's one example of why I'm sceptical about the repeatability on my Elite fluid trainer:

Friday: 20min near-maximum effort, average 'power' = 330W (this is almost certainly an overestimate ), average speed from Garmin = 31.7km/h, average heart rate = 161bpm (93% of MHR, range 90-98% MHR)

Sunday: 60min fairly comfortable, average 'power' = 323W, average speed from Garmin 31.5km/h, average heart rate = 141 bpm (81% of MHR, range 78-85% MHR)

Tyre pressure was the same, warm-up was the same. So based on these sessions, my avHR to maintain 31.7km/h for 20 minutes is about 161bpm, but I can maintain 31.5km/h for 3 times as long at an avHR of only 141bpm :?

For both sessions my cadence/speed drift upwards throughout (as the unit gets warmer and the resistance falls away) with no increase in RPE.

So what this actually tells me (something I've known for a while) is that if I do intervals then unless I progressively increase the speed that I do them at they're actually getting easier. The speed may be useful for comparing the same session, but as an accurate proxy for power its pretty useless.

Bronzie

oldwelshman wrote:

But did it help you win races?

Miiiiiiaaaaaoooooooow! You know how to hurt a guy!

Thing is, when you find out you've been fitted with a 1.0L 3-cylinder diesel engine instead of the 3.5L V6 turbo you ordered, then you better get good at engine tuning.

Thrashing myself silly on the turbo 4 nights a week certainly isn't making me go any slower, that's for damn sure.

Jeff Jones

Alex_Simmons/RST wrote:

I attacked early on for about 4 laps but my partner wasn't able to contribute sufficiently to make it stick, so I just rolled with the group and waited, launching my attack over the second pimple into the NE wind (about 600 metres to go). They all just looked at each other thinking I was going way too early. I knew better given the wind on that day.

Jeff of course knows the circuit very well, and that is an attack just before the final technical part of the circuit leading onto the 400m long straight.

NP for the ~48min was 287W

Australia Day crit Tuesday, that won't be quite so "easy".

That is one of the best places to attack on that circuit, because it's just before people want to wind up for the sprint. I've won a few races myself doing that. It hurts though, as it's 1min flat out.

Good luck on Tuesday!

(Sorry to take things OT but it's good to see you win)