Do I need a Power meter for outdoor riding?

power-meter

#1

Only started using a PM recently which is on my smart trainer. Wouldn’t mind one on my outdoor bike but are they worth it. I’ve always used a monitor to guide me. The PM’s are a little costly as well??


#2

If you want to do accurate interval training outdoors then yes.

If you mostly do group rides where all you do is ride at the pace the group dictates then other than for looking back at impressive numbers after they are of questionable value.


#3

The single biggest reason for using a power meter is to make sure you are riding easy on a recovery day. The improvements from training take place while the body is recovering. If you screw up a recovery day, you are simply flushing your hard workouts down the drain. Will you still see improvements if you ride a little too hard during a recovery workout? Yes. However, the overall benefits will be diminished. At the same time, you do not need a power meter to nail a recovery day. Easy means easy. So ride easy :grin:. When in doubt, error on the side of caution when it comes to recovery.

The second reason to own a power meter is Pw:HR and Efficiency. Checkout these articles by Training Peaks:

a. https://help.trainingpeaks.com/hc/en-us/articles/204071724-Aerobic-Decoupling-Pw-Hr-and-Pa-HR-and-Efficiency-Factor-EF-

b. https://www.trainingpeaks.com/blog/how-to-use-aerobic-decoupling/

The third reason to own a power meter is simply found in the data it provides you with. Overall, a power meter is more accurate than RPE and HR derived TSS. From my perspective, a power meter is objective and provides relatively accurate data. It will definitely show you if your group ride was harder or easier this week when compared to previous ride files. As well, your power files allow you to accurately track your improvements which will help you determine what type of events you are suited for.

The fourth reason to own a power meter is based upon instructing beginning cyclists who are new to training with a structured program. From experience, the easiest way to teach a beginning rider about their efforts is to have them use a power meter. Once they get a feel for power, they begin to understand RPE. Power is an output. HR is an input. RPE is a feeling.

A power meter is an expense, but I see it as money well spent.

Be Well and Ride On!


#4

Yes, especially if you want to be able to accurately and consistently monitor your training volume & intensity when including outdoor rides.


#5

To state the obvious, no, you don’t need a Power Meter. People have ridden and raced bikes for years without them and you can enjoy riding and race without one.

They are a useful tool however but whether it’s worth it to you depends entirely on how you use it.


#6

To add to Gordon’s post, I would think that the major advantage of a PM is to precisely hit target effort levels during structured training - this can be hard to do with HR alone, especially on shorter intervals. If you are doing most of your structured training on your smart trainer, then you are probably getting most of this benefit anyway.

If you are still considering a PM for outside, PM prices have certainly come down in the past 2 years, and you may want to look at some of the cheaper single-sided PM’s or perhaps Watteam Powerbeat.


#7

I went the other way and sold my pedal power meter for most of the reasons above.


#8

It is such a loaded question…

If you want to track your training outside and inside then yes, you need a power meter. You don’t need to look at the numbers while you’re outside, but you do need to track them to see what you’ve done to yourself when you’re done the ride.

But you don’t really need one - bikes work fine without them, and plenty of people don’t use them outside and are doing really well.

Need depends on you, there is no universal answer to this question


#9

I believe power meters are fantastic tools, albeit when coupled with heart rate and RPE.

My use-cases are the following:

  • Pacing in ultra-distance events. Heart rate and feeling though are very important too.
  • Tuning my “aero” position. This is a trade-off between comfort, power produced, and aerodynamics. For the “comfort” element I monitor how I feel and my HR levels. Power is the only “true” constant in the comparisons.
  • Monitoring my adaptation for my aero training. This is related to the previous point. I track my HrPW ratio (heart rate to power ratio) and aerobic decoupling over my training period to see if I am improving (in the aero position).
  • Monitoring my adaptation for cadence on long, steep climbs. In real-world steep climbs your cadence is limited by the gearing at your disposal. You may be able to hit an X amount of power at 90+ rpm on the trainer in erg mode, but find that the same amount of power outside can be produced by significantly lower cadence. I use the PM outside to gauge and train my real cadence on climbs at a target power. It also helps me see if I’m improving over time.
  • Sweet spot intervals outdoors! Those are the most tricky for me to nail, so a PM is awesome for it.
  • Finally, for recording the same power indoors and out. The power coming from your trainer is most probably going to be different from power being reported by a power meter, so I use the PM for both.

I don’t race so I can’t report on any experience using “matches” (W’), in-ride recovery (I think it’s “tau” or something), and such. But I hear great things about such uses.

However, I find that when I become too much of a slave to the power meter (outside) it ruins the experience of riding outdoors, and also wreaks havoc on my ability and propensity to “listen” to my body.


#10

I love having a power meter outdoors. I have one on my road bike (Quarq d-zero) and will put one on my next mountain bike. Speaking as a non racer, the benefits I see are:

  1. Very useful pacing tool for turns on the front when group riding.

  2. Great for pacing climbs, particularly longer climbs. I relied on mine heavily for a long Gran Fondo I did earlier in the year (Falls Peaks Challenge).

  3. It is really good for adding stress scores for outdoor rides into the trainer road calendar.

  4. Finally, it becomes a surrogate speedometer, which I quite like. In fact, 3 second power has replaced speed as a moment to moment metric on my Garmin.


#11

I didn’t see it above so I thought I’d mention the only real use case I have for a powermeter outdoors: pacing myself up hills. Judging gradients and initial bang is hard. If you are fresh the gradients seem lower and it is easy to go into the red. Easy long rides I could do by Heart Rate.

You don’t need an expensive flashy one though. I just use a Powerpod equivalent. They do a ‘lite’ version without the bells and whistles. Even the full price of the lite is only $199 and it doesn’t require much to attach.

The numbers are consistent with itself, but may be different than a standard powermeter, but then the numbers from indoor trainers are often bonkers anyway (and the cooling effect of outdoors, effect of gradients and so on limit the similarity anyway). You just learn that it reads 10w low etc. I used to calibrate them using a crank power-meter that I moved between bikes, but I got bored. It makes no difference.


#12

I got to admit that I’m hooked on having a power meter on my bikes. Many of the reasons have been mentioned above. Pacing on long rides and pacing on hill climbs are especially helpful.

The other aspect I really like is to track overall performance on rides the I repeat fairly often. This is where I can really see what kind of progress I’m making. For example I’ve made progress on 3 - 4 hour long road rides this year where I’m able to maintain power better in the later portions of the ride. It’s super easy for me to look at data from rides early in the year and compare it to where I am now.

For mountain biking it’s interesting to see what kind of peak powers I hit on the shorter punchy stuff. I don’t pay a lot of attention to it during the ride, but its fun to look back on it afterwards. However on the long climbs its nice to keep on eye on the PM and make sure I’m not going to blow myself up.

I haven’t used it a lot, but Bestbikesplit.com, something Jonathan mentions a fair bit, can also be quite valuable. I used it the first time I rode up Haleakala do get a better idea how I should pace.

Ultimately whether it is worth it or not is an individual decision, but I feel strongly I get a lot of value out of the PM’s on my bikes and it adds to my overall enjoyment of things.


#13

Assuming you have a smart trainer indoors, it depends on what kind of riding outdoors do you do. If you only do group rides or mass-start race then no, it’s not very important and you probably won’t even look at your power. If you do solo rides or TT then it’s very handy in pacing yourself and invaluable if doing outdoor intervals if that’s a thing that interests you (most people tend to leave the intervals for indoors but a lot of professional do the opposite)

In any case, it’s great to have the ride data available and logged for historical TSS or power profile analysis later.

TL;DR do you need one? probably not… but if you have some cash saved up it’s very nice to have. Depending on your crank situation you could get a second hand Stages or similar for pretty cheap