Why Ride With A Power Meter?


A long time ago, in a city far far away, I was pretty fast. At least I like to think I was. No, I’ll stick with I was pretty fast. I raced, commuted, and just generally spent every waking minute not at work on my bike. I was probably putting in close to 300 miles a week- and like most young men, I road as hard as I could everywhere I went.

Life was good.

I was also 25, had a “career” that barely warranted the term, and no family or responsibility.

Fast forward 10 years, and things have changed a little bit. Granted, since I have the privilege of working at a bike company, I probably have a little bit more time to ride than most other cyclists—but I still have a pretty demanding job, a relationship, and general life commitments that cut into my riding time.

So how was I going to accomplish my 2015 goal of getting close to 25-year old fit without all that endless free time to ride?

Enter the power meter.

Like most people about my age, I exist in a kind of weird place with technology. Old enough to have experienced a significant chunk of life without it, young enough to be expected to be on trend. This is my relationship with the power meter.

When I first got into cycling, power meters were around. They were also insanely expensive—far more than I would ever contemplate spending on something that wasn’t an entire bike. There was also a prevailing attitude at the time that (to paraphrase a famous bike blogger) if you weren’t a pro, having a power meter was kind of like hiring an accountant to tell you how poor you were. It was just difficult to see the value to the everyday cyclist at the time.

With more options now than ever, power meters have become affordable for most cyclists
With more options now than ever, power meters have become affordable for most cyclists

Well, obviously things have changed quite a bit. The price of power meters has come down drastically, and continues to fall as new players enter the market. The other big game changer is the availability of software like Strava or Garmin Connect. Whereas before you really needed a coach who understood what power meant to get the full benefit, Strava Premium or Garmin Connect now give you some pretty powerful analytics tools that let you be your own coach.

So how has using a power meter helped me get back to a decent level of fitness?

1. You Know Where You Stand

This is probably the most important aspect of having a power meter. I used to mostly ride by feel and MPH. But the funny thing about MPH is that it’s really deceiving. Things like terrain, wind, tire and clothing choice can all drastically impact your ride. I think every cyclist knows that demoralizing feeling of looking down at your computer and seeing a much lower number than you were expecting. The power meter does away with that, since power is a measurement of how hard you’re working, regardless of speed. 300 watts is 300 watts, whether you have a brutal headwind or not.

But to know what the power numbers mean, you need to do two things: you need to do a Functional Threshold Power test; and you need to spend time riding with it, staring at your Garmin. The FTP test is basically a 20 minute time trial best done on a trainer. Go as hard as you can for 20 minutes without blowing up, and that’s your Functional Threshold Power. This is your baseline power output. Not gonna lie, it’s terrible. But also very rewarding. The other part is easier. The more time you spend with a power meter, the more meaningful the numbers become. You’ll come to understand what are sustainable power outputs, when you can push a little harder, and when you’re in danger of blowing up.

The FTP Test: Pain that delivers valuable insights

2. You Ride Smarter

This is almost a cliché, but it’s true. A power meter will help you ride smarter. What does that mean? For most people with limited time to ride, there is one truism: your hard rides need to be harder, and your easy rides need to be easier. This is possible to do without a power meter, but it’s much more difficult.

This is actually where I found the most benefit. Before I had the power meter, I don’t think I was going nearly as hard as I should have been on my “hard” rides, and I was pushing way too hard on my easy rides. Having the concrete number of the FTP test to chase, I’ve been able to really push myself to the limit on intervals or time trial days. On the flip side, it’s much easier to go out for a recovery spin and say “I’m not going over 150 watts today” than it is to say “I’m not going over 15 mph today”.

This is where the real training benefits occur: with truly hard efforts and truly easy recovery.

3. You Can Track Your Progress

Again, you can use heart rate or MPH to try and track your progress—but these are fickle beasts and subjects to the whims of nature and caffeine. Using power gives you a consistent measure of your progress over time. Strava Premium gives you a tool called the Power Curve that lets you compare the power output on your last ride to the average power of a given time period, such as the last year or last six months.

This is a really good way to chart your progress as a rider and see how you are improving, as well as areas you need to work on. For instance, last year I noticed that my long endurance power had improved significantly, but my peak anaerobic sprinting power had worsened. Using that, I was able to put together some interval workouts for myself that targeted that specific weakness.

Utilizing features like the power curve can help you track your progress over time. Here, the dark line shows my power values for the last 6 weeks, while the light line shows it for the previous spring. As you can see, I’m a little off where I was last year.

4. Resting

Sometimes as cyclists we can be our own worst enemies, and we easily fall into the Fitness Trap. After a solid few months of training, most of us notice that we can quickly go from feeling great to feeling a little tired and a little slower. We’re having trouble on routes we used to destroy. The natural solution is to think we need to train more. So we go out and ride more miles, but just keep getting slower, more fatigued, and generally feeling terrible on the bike.

This is where having a long term, power-based view of your performance is really helpful. In early August of last year, my performance took a worrisome turn for the worse. I should have been ramping up for my key event of the year, but instead I was getting dropped from my usual group rides, having difficulty staying with the lunch ride crowd on hills, and feeling like my legs were empty on hard efforts. My initial instinct was that I had been slacking on miles, and needed to put in even more saddle time.

But utilizing the power of Strava, it didn’t take long to see what the real problem was. My power outputs had been steadily increasing for months, before starting a sharp decline over several weeks, and then promptly falling off a cliff.

3104_CHCB 2
Sometimes the greatest value in a power meter is telling you when you need to rest or have a few very easy days

So what was the problem? I needed rest. After a week off the bike, things where back to where they should have been, and in fact even a little better.

That was a really valuable lesson. Sometimes the biggest advantage of power data is not only that it can tell you how hard to ride, but also when not to ride. I now have a rule set for myself that whenever my power values dip by a certain percentage over a few days, it’s time for a few days off the bike.

So is it working?

Absolutely. Without a doubt, a power meter is the best investment I’ve ever made in my cycling. The performance gains you’ll make easily dwarf anything else. Sure, there are plenty of other upgrades you can make that give you solid performance gains, and they look pretty cool too. But if you want to make serious, measurable gains in your fitness and the raw engine that’s driving your bike, the power meter is the place to spend your money.

Stages Cycling offers single-sided crank-based power meters at a great value

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s