Fitbit ChargeHR vs Polar FT4

Lianne Gong Wasserstrom
Aug 3, 2015
3 min read

** BodyRx is not affiliated with either brand, nor were we paid/selected to do this comparison. Opinions are our own.

I am a sucker for fitness gadgets / wearables / apps. Back in 2012, we hopped on BART to head to Union Square because Nike Town was the closest place that had the Fuelband in stock. The Fuelband was fun for a little bit but I found it lacked a lot of oomph when it came to measuring what was most important to me. Fast forward to 2014, we were quick to purchase the Polar FT4 heart rate monitor / watch to help us track the intensity of our workouts. I still love the FT4 to this day. Fast forward another year to last week 2015, we took the leap and purchased the Fitbit ChargeHR. And our findings thus far are just so-so.

Fitbit ChargeHR

Pros:

All-day heart rate monitoring
All-day calorie burn
Integration with MyFitnessPal (which is an app I LOVE)
No chest strap
Sleep monitoring

Cons:

Heart rate monitoring during rigorous activity is questionable, at best
Not waterproof or shower proof
Must be worn in a specific location, or readings will be off

Polar FT4

Pros:

Very accurate heart rate monitoring during activity
Waterproof
Essentially, foolproof

Cons:

Chest strap can be uncomfortable
Activity-only monitoring
No integration with any apps I use (yet?)
No sleep monitoring

I have ran comparisons of the Fitbit ChargeHR and the Polar FT4, both at rest (i.e.: normal day-to-day activity) and during exercise (i.e.: running, lifting weights, playing hockey).

Comparing: Heart Rate Tracking & Calories Burned

Since this is the only mutual data point, these are the only things I can truly compare. Over the past week, I wore BOTH the Fitbit ChargeHR and the Polar FT4 during workouts.

At rest, both monitors are on point. They both read equally and read within 1-2 BPM of my manual heart rate check. No qualms here!

However, during a bout of exercise, the Fitbit ChargeHR fails miserably. I checked my heart rate after a high intensity interval, and the FitBit read 124 BPM where my Polar read 167BPM. That’s quite the difference! Maybe it was just during treadmill exercises that it was inaccurate. I moved onto my weight lifting… and still a huge variance.

I decided to probe into this discrepancy a little bit more. Fitbit suggests wearing the tracker higher up on your wrist, so I re-tested. Nope. Made no difference, and it kept sliding down (and therefore not tracking my heart rate since the LED lights were not flush against my skin). They also suggested loosening the tracker. Nope. Still a huge variance. After a few workouts (and testing through my workouts, and my husband’s), I remain really disappointed.

I DO like how the Fitbit breaks down your workout into “zones”, allowing you to see how much time you spent in cardio/fat burn/peak. But… if the heart rate is incorrect, what good is this data?

The Polar FT4 is not perfect either. If the strap sensors are not moist, it will not read your heart rate. Or, if the strap is too placed too high, it won’t read. If it’s too low, it won’t read. Funny twisting motions make the strap monitors “detach” from your body, and won’t read your heart rate.

But, the Polar FT4 has been fairly consistent in tracking my heart rate.

—

Fitbit average heart rate during exercise: 126 BPM

Polar average heart rate during exercise: 169 BPM

** biggest variance (pictured)

Fitbit average heart rate during exercise: 114 BPM

Polar average heart rate during exercise: 142 BPM

** smallest variance

Fitbit calories burned during exercise: 302

Polar calories burned during exercise: 601

** biggest variance

Fitbit calories burned during exercise: 121

Polar calories burned during exercise: 245

** smallest variance

—

I have been debating on whether I will keep or return the Fitbit ChargeHR. While I am really disappointed in its ability to accurately track heart rate during exercise, I really like the “all day snapshot” and the sleep tracking.

I will continue to wear my Polar FT4 during workouts; I am not giving that up. The future of my FitBit has yet to be determined. . . Thankfully, Amazon Prime has a great return policy. :)

Have you tried either the Polar watches or the Fitbit ChargeHR / Surge? If so, comment below and let us know what you think? Are you using a different fitness tracker? Let me know what you love!