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Why you should be measuring your wattage as you ride

The power meter market is getting ever more crowded and prices have tumbled over the past two or three years. No power meter is cheap, but there are several options out there that are affordable to many people. If you’re not using one already, this winter is the perfect time for you to start training by wattage. Here’s why you should consider it.

1. Quality data & no excuses

A power meter measures exactly how hard you’re working regardless of the terrain, the conditions, your fitness, or any other factor, and it’ll give you figures that you can meaningfully compare over time to gauge progress. Your speed over a set course might be affected by a headwind, for example, and give you  false impression of your fitness, but measuring power tells you exactly what you’re putting out.

PowerTap hub (CC BY 2.0 Glory Cycles).jpg

2. Make the best use of training time

A power meter takes the guesswork out of  your training effort, allowing you to train time efficiently. You can plan exactly what you need to do, then go out there and do it, taking your cues from the numbers on your bike computer.

Powertap P1 pedals 3

Powertap P1 pedals 3

3. Pace yourself

You can use a power meter to pace an event too. If your training tells you that you can hold 250w for an hour, for example, you can work out a strategy for your next 25-mile time trial based on that.

Verve Cycling Infocrank Classic.jpg

Verve Cycling Infocrank Classic.jpg

4. Work on your weaknesses

A power meter helps you identify weaknesses in your fitness. If your anaerobic endurance lags behind other areas, there’s no hiding from the figures so you know exactly what you need to work on.

Garmin Vector 2S pedals

Garmin Vector 2S pedals

5. Get some rest

A power meter can tell you when you need to rest. For instance, if your heart rate is markedly higher than normal for a particular power output, it could be that you’ve not recovered sufficiently from last time and you need to take it easy.

Stages Cycling power meter sensor side .jpg

6. Tune your position

You can use a power meter to test the aerodynamic effects of altering your ride position and/or equipment. Ride a given course at 20mph, say, and take your average wattage. Then make changes to your setup and ride it again at the same speed. If your average wattage is lower, you’ve found some extra efficiency. 

For more information on power meters go to our buyer’s guide.

Mat has worked for loads of bike magazines over 20+ years, and been editor of 220 Triathlon and Cycling Plus. He's been road.cc technical editor for eight years, testing bikes, fettling the latest kit, and trying out the most up-to-the-minute clothing. We send him off around the world to get all the news from launches and shows too. He has won his category in Ironman UK 70.3 and finished on the podium in both marathons he has run. Mat is a Cambridge graduate who did a post-grad in magazine journalism, and he is a past winner of the Cycling Media Award for Specialist Online Writer.

21 comments

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drosco [415 posts] 1 month ago
1 like

Reasons not to use a power meter - you're not a pro and you should just enjoy riding your bike.

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GreatSageEqualO... [1 post] 1 month ago
5 likes
drosco wrote:

Reasons not to use a power meter - you're not a pro and you should just enjoy riding your bike.

If I just rode my bike to look at the countryside and take in the fresh air, I'd agree with you. But I also ride to improve my fitness, speed and stamina - which is part of the enjoyment for me too - so why not buy a power meter if it adds to that part of enjoying riding my bike??

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lostshrimp [8 posts] 1 month ago
2 likes

"A power meter can tell you when you need to rest. For instance, if your heart rate is markedly higher than normal for a particular power output, it could be that you’ve not recovered sufficiently from last time and you need to take it easy."

 

My response to fatigue is tottaly the oposite my hear rate doesn't get anywhere near as high when I am fatigued (I think that's normal). I get markedly higher heart rate if I am truely rested and taken time off the bike

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PRSboy [94 posts] 1 month ago
2 likes
lostshrimp wrote:

"A power meter can tell you when you need to rest. For instance, if your heart rate is markedly higher than normal for a particular power output, it could be that you’ve not recovered sufficiently from last time and you need to take it easy."

 

My response to fatigue is tottaly the oposite my hear rate doesn't get anywhere near as high when I am fatigued (I think that's normal). I get markedly higher heart rate if I am truely rested and taken time off the bike

 

Yup me too.- HR much higher for a given effort after a break.  Presumably a function of detraining.

I've always thought resting heart rate a good guide to the extent of recovery, i.e if its elevated, then not fully recovered.

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chihuahua [10 posts] 1 month ago
0 likes
GreatSageEqualOfHeaven wrote:
drosco wrote:

Reasons not to use a power meter - you're not a pro and you should just enjoy riding your bike.

If I just rode my bike to look at the countryside and take in the fresh air, I'd agree with you. But I also ride to improve my fitness, speed and stamina - which is part of the enjoyment for me too - so why not buy a power meter if it adds to that part of enjoying riding my bike??

Of course if you think a Power Meter will help but without one I still know whether my fitness, speed and stamina has improved or not.  I much prefer going by feel rather than raw figures because even if u include feel you're drawn to what 'science' is telling you. I also know when I'm tired and the specific signs that'll b specific 2 me because I've learned to listen to and heed my mind and body. A Power Meter can't do that for me and I've had an SRM.

Having said the above I of course fully acknowledge that everyone needs to choose for themselves and so just sharing my experience.

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alansmurphy [1186 posts] 1 month ago
0 likes

So 5 and 6 are complete bollocks...

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CXR94Di2 [1856 posts] 1 month ago
1 like

6 is valid but difficult to achieve. Like most real world aero testing

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alansmurphy [1186 posts] 1 month ago
0 likes

Bit 1 talks about valid data thus how likely are you to ride the exact same course in the exact same conditions? Headwind means if you rode that course at the same speed your power is likely to be higher suggesting your bike is less aero which wouldn't necessarily be true...

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Nick T [1099 posts] 1 month ago
2 likes

After a long day looking at spreadsheets for the accounting firm he works at, Steve enjoys nothing more than getting home to relax by thoroughly analysing his power data from the previous Sunday’s cafe run with the club and think about how he’d like to start racing next season

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shay cycles [402 posts] 1 month ago
2 likes

Six Reasons not to use a power meter:

If you actually want to road race and not yet in Le Tour then you won't need a power meter - a bold statement but here's why:

1 - The strongest and most powerful rider is often not the one winning the races - better to develop race craft and skills whilst building fitness through doing so.

2 - If a race winning break goes you are either in it, catch it or not - if your power meter says catching it is too hard then you might as well head back to the changing rooms and get changed.

3 - If there is not a race winning break then your job is to conserve energy for the sprint - you don't need a power meter to do that.

4 - If you can win with a lone attack then get on with it - a power meter might tell you how long you can make your effort for nut it won't tell you how well (and therfore fast) the chasing group will work.

5 - You could use the power meter for training and might get some benefits, but none that compare to finding where your strengths and weaknesses are by racing on a range of courses against opposition stronger than yourself. If there is no opposition stronger than yourself then you don't need a power meter (you just need to reduce the PEDs).

6 - If you are time-poor for training you could spend more time training if you stop spending so much time analysing you performance - again just spend the time on training and do the measuring by racing.

End result the power meter isn't really helping you (so a here's a bonus 7th reason - you'd be richer without it)

 

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davel [1967 posts] 1 month ago
1 like
alansmurphy wrote:

Bit 1 talks about valid data thus how likely are you to ride the exact same course in the exact same conditions? Headwind means if you rode that course at the same speed your power is likely to be higher suggesting your bike is less aero which wouldn't necessarily be true...

It becomes your main metric, as it's the most 'honest'.

Eg: you're doing a TT and have a time in mind. You might have a head or tailwind on the day, which is out of your control, and be quicker/slower than your target.

If you pick your target power, you can put that out regardless - the idea is it should be constant whether you have head or tailwind etc.

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Simontuck [182 posts] 1 month ago
1 like

I like something to aim for. If I'm training indoors (if you don't have a power meter do you still train indoors btw?) then I find it far easier to follow a set wattage than a 'perceived effort level'.

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davel [1967 posts] 1 month ago
4 likes
shay cycles wrote:

End result the power meter isn't really helping you (so a here's a bonus 7th reason - you'd be richer without it)

 

End result is it's another metric, like heart rate or speed, but pretty useful, and you'll either find money to buy a meter, or you won't.

Luddites gonna Ludd, yo.

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Yorkshire wallet [1566 posts] 1 month ago
0 likes

I use mine for pacing generally. If I'm doing double digit climbs then I'm probably on the last cog and you've got to do what you've got to do but elsewhere it's nice to know what effort you're putting in. 

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shay cycles [402 posts] 1 month ago
2 likes
davel wrote:

Luddites gonna Ludd, yo.

Not so much a Luddite as a realist or pragmatist - if it isn't necessary to improve performance then I tend not to go with it, especially on a race bike, but if it does then I've generally used it.  Luddites on the other hand wanted to prevent progress because it threatened them.

Things I adopted really early on included concealed brake cables, seven speed gear blocks, 12 tooth sprockets and shoes with ratchet fixing - all things with a direct benefit for racing performance. I also pioneered left hand rear shifting with bar-cons in cyclo-cross (before Simunek) and made my own crush proof double toe clips. 

Things I didnt' adopt early included indexed gearning, tub-tape and clipless pedals, waiting until they were good enough to race on (early indexed gearing was OK for knocking about on but neither quick nor reliable enough for racing - it wasn't introduced in top level stuff but in lower end groups). 

I may well be old fashioned in some of my views but Luddite and old fashioned are very different things.

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davel [1967 posts] 1 month ago
1 like
shay cycles wrote:
davel wrote:

Luddites gonna Ludd, yo.

I may well be old fashioned in some of my views but Luddite and old fashioned are very different things.

You're being slightly disparaging about Luddites, but I get your point. However, your previous post was more ideology than pragmatism. You've made your mind up that power meters are A Bad Thing and will find arguments to fit that - there's an element of defensiveness there - despite fairly logical arguments for power being a useful metric. Your way of doing things can't/won't incorporate it, and that seems pretty Luddite to me.

Never done a time trial largely, or with the first half, into a headwind? Ever done an ironman on a very different course from those before and wanted to have the legs to get round the marathon bit? Ever done over-unders that you wanted to be accurate? Ever done a winter on the turbo?

Of course I could have done all of them without a power reading, and probably have before, to some extent. But I also could get by without a TT bike, the number of gears I have, indexed gears, clipless pedals, turbo trainer, TrainerRoad.... They're all instances I've found using power readings very useful. There a loads of others. You don't have to like that, but don't kid yourself that you're some racing purist because you eschew a technology that you yourself don't understand the benefits of.

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Yorkshire wallet [1566 posts] 1 month ago
0 likes

I guess it's a bit like saying you don't need a rev counter because you can hear you engine.

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davel [1967 posts] 1 month ago
1 like
Yorkshire wallet wrote:

I guess it's a bit like saying you don't need a rev counter because you can hear you engine.

But you can tell the engine's revs by listening to it. The sound doesn't change because the car feels a bit knackered or if it's going uphill or into a headwind - it's consistent.

You can't tell what power you're putting out by how it feels - perception is sometimes way out.

There seems to be a perception (unfairly applied to Chris Froome) that the primary purpose of a power meter is to ensure you don't blow up while racing. It works both ways - it can tell you you've got more in the tank than you think, and you can follow the break, or go yourself. As for training - it's a way of being really efficient so a timesaver, and, unless you really want to, you don't need to spend ages crunching numbers.

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Spacer [22 posts] 1 month ago
2 likes
lostshrimp wrote:

My response to fatigue is tottaly the oposite my hear rate doesn't get anywhere near as high when I am fatigued (I think that's normal). I get markedly higher heart rate if I am truely rested and taken time off the bike.

Of course, but that's not the opposite because you've missed power out of the equation and that's the important bit!! You're not putting out the same level of power when you're fatigued.

alansmurphy wrote:

So 5 and 6 are complete bollocks...

No. Joe Friel: "There are going to be days when your heart rate rises above what you normally see by perhaps 10 bpm or slightly more just because of fatigue, overreaching, overtraining, too much caffeine or similar product, or a hot day. This is not unusual at all. You may need to back off and slow down or even abandon the workout that day. This happens to everyone from time to time."

http://www.joefrielsblog.com/2011/03/high-heart-rate-questions.html

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alansmurphy [1186 posts] 1 month ago
0 likes
davel wrote:
alansmurphy wrote:

Bit 1 talks about valid data thus how likely are you to ride the exact same course in the exact same conditions? Headwind means if you rode that course at the same speed your power is likely to be higher suggesting your bike is less aero which wouldn't necessarily be true...

It becomes your main metric, as it's the most 'honest'.

Eg: you're doing a TT and have a time in mind. You might have a head or tailwind on the day, which is out of your control, and be quicker/slower than your target.

If you pick your target power, you can put that out regardless - the idea is it should be constant whether you have head or tailwind etc.

I wasn't suggesting they don't have a use, I love data, merely that the reasons expressed in the list aren't actually correct.

And the same for the point above, I'm not saying a HR is necessarily the answer, wasn't comparing the two as such.

For my mind, objectives and budget then an HR monitor will do. If someone has a spare grand it's not for me to say what they spend it on. It's just the 6 reasons why you need aren't 6 reasons and very few will actually need...

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Spacer [22 posts] 1 month ago
1 like
alansmurphy wrote:

 I wasn't suggesting they don't have a use, I love data, merely that the reasons expressed in the list aren't actually correct.

You've not given evidence to suggest anything here is incorrect (as people have pointed out), but if you don't feel using power is right for you I imagine the rest of the world will be cool with that.