Dispelling nutrition myths, ranting, and occasionally, raving


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Which fitness tracker gives you the best calories burned for your workout? An experiment

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Remember my rant a little while ago about how you shouldn’t think of exercise and food as an equation to balance? Or my post about not using the exercise component of calorie counting apps? Well, I just wanted to add a little more to that conversation today.

I use a Garmin watch to track my runs and occasionally I’ll look at the “calories burned” out of curiosity. After a pretty fast longish interval run I noticed that the calories burned seemed rather low so I started scrolling back through and was puzzled to find a shorter easier run that supposedly resulted in a very similar caloric expenditure. That left me wondering how Garmin determined the calories burned during a run. I looked it up and it turns out that it’s related to heart rate. Sometime the heart rate monitor is wonky and (especially when it’s really cold out) will register a heart rate that would be more likely seen when I’m sitting on my butt than when I’m out booking it through speed work. That means that my Garmin (erroneously) registers minimal exertion and thinks that I’m not burning very many calories.

Today I decided to do a little experiment. I wore my Garmin, as per usual, which is synched to my Strava account. I also fired up the Nike+ Run Club app for the first time in ages and I set out on an easy(ish) 10k run. After the run, I also entered the time spent running at the closest average pace into myfitnesspal. All of these apps have my height and weight. Any guesses what the results looked like?

Garmin: 463 calories

myfitnesspal: 517 calories

Nike: 526 calories

Strava: 1371 calories!!!!

Now, I have no idea how many calories I actually used during this run, I’d wager Garmin was probably closest to the mark considering that the heart rate monitor seemed to be working properly. But Strava, what the actual hell?? Considering that Strava gets all of it’s data from my run directly from Garmin I find it amazing that it estimated I burned nearly three times as many calories as Garmin thought I did. I’m sure that if I had other apps and trackers I would have gotten slightly different results from all of them.

All this to say, if you’re exercising and tracking calories burned, you probably shouldn’t give that number too much weight. Try to think of exercise as giving you health and fitness rather than taking away calories and weight.

 

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Guest post: How accurate are running apps anyway?

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Finally, someone took me up on my request to write a blog post for me. Kidding. I was a little skeptical when I received a request for a guest post from someone I didn’t know and who’s background wasn’t nutrition. However, Sara took the spirit of my blog and applied it to running (my second love). I hope you all enjoy her post as much as I did!

Running apps for smartphones have been gaining momentum ever since they sprung from the starting block. Runners everywhere are strapping their phones to their arms and keeping track of distance run, pace and calories burned.

Or so they think.

How accurate are these apps, anyway? Can they really be as precise as a GPS watch?

A professional run coach named Matt Johnson decided to find out for himself. Using a running app for a smartphone, the same app for an Android phone, a GPS watch and a bicycle computer with a wheel sensor, Matt set out on a five-mile bike ride. The wheel sensor was the controlled variable of the experiment as it measures the actual ground covered by the wheel and is the same method used to measure race routes by USA Track and Field. He also conducted the same test while running the Chicago Marathon (obviously without the wheel sensor).

The results of the experiment showed the GPS watch was considerably more accurate than the running apps. The running app reported he ran 27.92 miles during the marathon, over a mile and a half more than what he actually ran!

So what are the risks? An inaccurate measure of your distance traveled will equate to an inaccurate measure of your pace. This will give you a false sense of achievement—or lack of achievement—and will lead to quite the wake-up call on race day when you suddenly can’t keep the same pace on a measured course.

A phone GPS differs from a running watch GPS in both design and function. A phone GPS device has a weaker signal and is designed more to find a general location and not a precise, pinpoint location like that of the stronger signal devices found in GPS watches. GPS devices in phones are generally smaller because they need to compete for space and signal strength with all of the other inner workings of a phone.

The GPS devices in a phone also perform differently than those of running watches. In a phone, the GPS does not track continuous movement but rather records timed snapshots of your location, kind of like a store security camera. The distance between the snapshots is then calculated as a straight line so movements like turns or zig-zags are not recorded. While it may seem minimal, these lost steps can really add up over the course of a long run.

Different phones and different apps all have different algorithms of calculating the distance traveled. You might be using one particular kind of phone or app and running alongside your friend, who has a different phone or app. The numbers produced at the end of your run will likely vary greatly.

So running watches are the way to go? Actually, a combination of both will give you the most out of your run. While watches may be more accurate, phones can provide additional data that many watches cannot.

There are GPS running watches on the market that sync up with smartphones to give you the best of both worlds. The watches will provide you with the pinpoint accuracy of your route while the phone provides additional data that can be analyzed and stored. As this article on Verizon Wireless explains, the phone can act as your own personal running coach. You can receive real-time coaching tips based on your pace and heart rate. Music will help keep your tempo. The data recorded by your watch will be instantly transferred to your phone to see your stride length, route map and more. Training plans will be altered for you based on your progress. There are running watches that are compatible with Android, iPhone and Windows devices.

So while a running watch provides greater accuracy of your run, smartphones provide a valuable source of additional data. Combine the two and let them run stride by stride.

About the author: Sara Upton is a freelance blogger and distance runner living in North Carolina’s Outer Banks. She enjoys long runs on the beach with her golden retriever, Sally.