Power Meter - Pointless?

davegilly

Is a power meter when cycling outdoors pointless? Or is there something wrong with mine. I’ve only gotten one recently and have come from a running and HR background and can’t make head nor tail of how it’s of any use outdoors.

I’m using an Assioma Uno and when outdoors the watts/zones are all over the place and I find it impossible to stay in a zones when doing a workout. If the road is flat as a pancake then it’s not too bad but any little bump, hollow, breeze etc affects the power by large variations so I could be in zone 2 one minute and then zone 6 30 secs later and everything in between - how are you supposed to train with that? If a workout states Zone 4 for 5 mins how are you supposed to stay in that zone on a windy rolling road? I’m using 3 second power btw which is what I believe is correct?

I’m tempted to sell the pedals and go back to HR training when outside and using power only when inside on a trainer. Any advice?

dahat

Look at your average & NP for the interval rather than for every 3 secs within target range.

gmacww

In my opinion a power meter is only useful if you understand the numbers and know exactly how to interpret them and put them into a functional training plan with a clear idea of what your target/goal is. Or alternatively you have a coach who does all that thinking for you. Without that it’s just another number on your display.

I no longer have one as I’m not racing anymore and really have no need to look to try and hit a certain number or that.

lennymc

https://www.amazon.co.uk/Training-Racing-Power-Meter-2nd/dp/1934030554

a copy of this should come with every power meter

G1032

You'll just need to learn how to control it but I don't honestly know how you could unintentionally be in "Z2 one minute and Z6 30s later"
You don't for example just accidentally go from 200 watts 400 watts in 30s without knowing you're putting out significantly more power and putting in significantly more effort.

If you're, for example, doing an endurance ride at say, 200 watts, you're going to have to go up even small inclines very very slowly and down pretty fast if you want to control your power input. You could well find yourself several times in a session in the 39/28 crawling up a small incline if you want to hold your watts steady. There is no getting away from that at those watts (200 I mean as an example)

If you're doing a harder effort like a VO2 Max session then, ya, it's going to be difficult to hold the exact wattage for the full 3 or 4 minutes or whatever. But you shouldn't really dip far outside your target power for more than a few seconds before steadying the ship again. And when you analyze your intervals afterwards, a good indication of a good interval will be your average power matching or being within a watt or two of you NP.

I also find that having the actual power reading as well as 3 sec power helps a lot. I look at actual more often than 3s tbh but I know many people prefer the 3s average. Each to their own. There's no right or wrong there.

davegilly

G1032 wrote: »

You'll just need to learn how to control it but I don't honestly know how you could unintentionally be in "Z2 one minute and Z6 30s later"
You don't for example just accidentally go from 200 watts 400 watts in 30s without knowing you're putting out significantly more power and putting in significantly more effort.

I may have had artistic licence there with that one.

The workout today had intervals of say 230-250 watts for 4 mins then 250-270 watts etc. I found it extremely difficult to stay in these ranges and when I looked at the data afterwards it's hard to see a difference between each interval as the variations were so wide they all look the same. Is that normal when on the road?

I tried to find the flattest section of road locally to do this but there was some rolling terrain rather than hills and I found controlling my power was impossible.

Bambaata

What are you displaying on your computer? It sounds like you have actual power being displayed. Better to have 3s average going and have the lap average also displaying. Power is very eratic but you should be able to hold it to 20-30w easily enough

ED E

davegilly wrote: »

I’m using an Assioma Uno and when outdoors the watts/zones are all over the place and I find it impossible to stay in a zones when doing a workout. If the road is flat as a pancake then it’s not too bad but any little bump, hollow, breeze etc affects the power by large variations so I could be in zone 2 one minute and then zone 6 30 secs later and everything in between - how are you supposed to train with that? If a workout states Zone 4 for 5 mins how are you supposed to stay in that zone on a windy rolling road? I’m using 3 second power btw which is what I believe is correct?

I'd be 90% sure you've not set your zones correctly and its using a default FTP of 150W or something.

themighty

davegilly wrote: »

I tried to find the flattest section of road locally to do this but there was some rolling terrain rather than hills and I found controlling my power was impossible.

For those shorter sets I'd pick a steady hill and do repeats. It's easier to hold power than on a flat road where you might be moving from +1 to -1 in gradient. Strava can be handy for spotting hills of decent length and gradient near you.

davegilly

Bambaata wrote: »

What are you displaying on your computer? It sounds like you have actual power being displayed. Better to have 3s average going and have the lap average also displaying. Power is very eratic but you should be able to hold it to 20-30w easily enough

I'm using 3 second power.

davegilly

ED E wrote: »

I'd be 90% sure you've not set your zones correctly and its using a default FTP of 150W or something.

You could be right. FTP is set to 187W off a 20 Min Garmin test. I know it's not the best but it's all I have for the moment.

ED E

davegilly wrote: »

You could be right. FTP is set to 187W off a 20 Min Garmin test. I know it's not the best but it's all I have for the moment.

That should be enough to keep your zones from being just a few watts wide, double check what the lower zones say.

Macy0161

I use 30 seconds when doing workouts outside. I don't really look at it until post ride unless I'm specifically trying to pace a climb or it's feeling harder than it should on a "normal" spin either solo or group.

lennymc

davegilly wrote: »

You could be right. FTP is set to 187W off a 20 Min Garmin test. I know it's not the best but it's all I have for the moment.

you should do a test to establish your zones first - there are a few different protocols, which vary in levels of 'whydididecidetodothis-ness'. the 20 minute one is considered (95% of max 20 minute effort) quite accurate, but there are 8 minute tests, ramp tests, and more. Lots of info on google.

The main thing is consistency over time, so if you do one test now, do the same test in 6 weeks to see if you are progressing.

What software are you using to track your power? I find strava & Intervals.icu to be quite good for analysing rides afterwards.

Chips Lovell

Lap average for each interval is the way to go.

Gallant_JJ

Chips Lovell wrote: »

Lap average for each interval is the way to go.

Have your bike computer show '3 sec average and a 'lap average'. At the start of a block hit the lap button, aim to get the lap average to where you need it to be in your programme, but use the 3sec average to regulate your immediate effort up or down accordingly to approximate watts your aiming for.

davegilly

Either I'm doing something very wrong or the meter is broken.

This evening I was supposed to do intervals - Zone 4 for X minutes and then Zone 2 recovery. I had both HR and Power on the screen. The HR, while it took 20-30 seconds to get the Zone 4 each time and longer to get back down to Zone 2 for recovery was nice and stable and a usable metric. Power on the other hand was all over the place. Anything from zone 2 - 6 depending on the terrain, direction (head wind) or gear.

I must be doing something very wrong. I presumed power would be stable like HR but this doesn't seem to be the case. I'm never going to be a racer and only doing this for fun and to get fit so I think I'll get rid of the pedals again and stick to HR - for outdoors anyway. Makes life a bit easier I think!

harringtonp

davegilly wrote: »

I may have had artistic licence there with that one.

The workout today had intervals of say 230-250 watts for 4 mins then 250-270 watts etc. I found it extremely difficult to stay in these ranges and when I looked at the data afterwards it's hard to see a difference between each interval as the variations were so wide they all look the same. Is that normal when on the road?

I tried to find the flattest section of road locally to do this but there was some rolling terrain rather than hills and I found controlling my power was impossible.

The 3 fields you need on your display are 3s power , lap.power and lap time. Hit your lap button and do your 4 mins keeping the lap average as close to the target wattage as possible. Use the 3s number to modulate the average and don't worry about it jumping. Pick your stretch of road carefully. Rolling is ok once the downs are straight and you can keep the power on. It doesn't take long to figure what stretches of road work well.

Takca

davegilly wrote: »

Either I'm doing something very wrong or the meter is broken.

This evening I was supposed to do intervals - Zone 4 for X minutes and then Zone 2 recovery. I had both HR and Power on the screen. The HR, while it took 20-30 seconds to get the Zone 4 each time and longer to get back down to Zone 2 for recovery was nice and stable and a usable metric. Power on the other hand was all over the place. Anything from zone 2 - 6 depending on the terrain, direction (head wind) or gear.

I must be doing something very wrong. I presumed power would be stable like HR but this doesn't seem to be the case. I'm never going to be a racer and only doing this for fun and to get fit so I think I'll get rid of the pedals again and stick to HR - for outdoors anyway. Makes life a bit easier I think!

I don't think this was ever going to be the case, HR lags while power numbers update almost instantly. If you were just using HR you are also in the wrong zone, you just don't know about it yet, You might find it beneficial to not display HR on your computer and only go by power.

Power will jump around a lot as terrain changes (I think more for heavy riders but maybe thats just me giving myself an excuse), you need to react quickly and get the power back to where it needs to be and I think that just takes practice. I usually display lap, 30s and 3 second power, and usually adjust what I aiming the 3s power for slightly if the lap power drifts away from my target.

I also find it very difficult to stick to specific power outside, any time I do manage to keep it close to target it involves concentration and on a rolling terrain a lot more gear changing then I would normally do.

Finally as was mentioned on another post if there is down hill sections they need to be pretty straight and not too steep. So you need to plan your route to suit. This morning I was pushing downhill at 64km/h just to keep the power up where I wanted it.

Macy0161

Takca wrote: »

I also find it very difficult to stick to specific power outside, any time I do manage to keep it close to target it involves concentration and on a rolling terrain a lot more gear changing then I would normally do.

fwiw TrainerRoad outside workouts give you a range for intervals rather than the specific power on the inside workouts. I've tried them a few times, but as mentioned, you have to find the right terrain, and tbh I've no interest in hill repeats or going up and down the N11/ old N11. I'd rather do my work inside!

dahat

davegilly wrote: »

Either I'm doing something very wrong or the meter is broken.

This evening I was supposed to do intervals - Zone 4 for X minutes and then Zone 2 recovery. I had both HR and Power on the screen. The HR, while it took 20-30 seconds to get the Zone 4 each time and longer to get back down to Zone 2 for recovery was nice and stable and a usable metric. Power on the other hand was all over the place. Anything from zone 2 - 6 depending on the terrain, direction (head wind) or gear.

I must be doing something very wrong. I presumed power would be stable like HR but this doesn't seem to be the case. I'm never going to be a racer and only doing this for fun and to get fit so I think I'll get rid of the pedals again and stick to HR - for outdoors anyway. Makes life a bit easier I think!

What power meter are you using? is everything up to date and calibrated etc?

Also you'll need to pick terrain for the required effort and learn what roads are best for each. I've set efforts outside this time of year and by applying the above i can get 90% with range required by looking at 3 secs power, lap avg & NP lap. It just takes time and all coaches recommned a settling period of a few weeks for any new power meter user.

Macy0161

They covered outdoor workouts on the latest TrainerRoad podcast - what fields they use, settings etc. Obviously somewhat specific to TrainerRoad outdoor workouts, but probably applicable to any outdoor structured work.