Salt Lake City's Fitbit Fail: Altitude Lies & Heart Rate

By Franklin Everett Shaw

January 6, 2026

Are you gasping for air just walking to your car in Salt Lake City? Your Fitbit might be lying to you about your workout. High altitude throws a wrench into the accuracy of wearable fitness trackers, especially when it comes to heart rate and activity levels. This guide is for Salt Lake City residents who want to get the most accurate data from their Fitbits, even with the thin air.

Let’s face it: sea-level fitness advice doesn’t cut it here.

Fitbits, while generally reliable, struggle with the lower oxygen levels and increased physiological demands of our mountain environment. This leads to inflated heart rate readings, underestimated calorie burns, and inaccurate distance tracking. We’re going to dive deep into how to fix these issues.

First, understand why altitude messes with your Fitbit. Lower oxygen forces your heart to work harder, even at rest. Your Fitbit, relying on wrist-based sensors, can misinterpret this increased effort as intense exercise, even when you’re just strolling down Main Street.

One of the biggest culprits is inaccurate stride length. Fitbits estimate distance based on your stride, which is typically calibrated for flat terrain. Uphill climbs, common in Salt Lake City neighborhoods like the Avenues or Federal Heights, shorten your stride. This means your Fitbit will underestimate the distance you’ve traveled, leading to inaccurate pace and calorie burn calculations.

To fix this, manually calibrate your stride length. Find a flat, measured distance (a track is ideal). Walk or run that distance multiple times, counting your steps. Divide the total distance by the total number of steps to get your average stride length. Enter this value into your Fitbit app settings. Do this for both walking and running, as they will differ.

Another common issue is inaccurate heart rate readings. Wrist-based heart rate sensors can be affected by poor circulation, skin tone, and even the tightness of the band. At altitude, these factors are amplified.

Consider using an external heart rate monitor, like a chest strap. These devices are far more accurate than wrist-based sensors, especially during intense activity. Pair it with your Fitbit for more reliable data. Many chest straps connect via Bluetooth and are compatible with most Fitbit models.

Let’s talk about specific Fitbit settings. Make sure your Fitbit profile includes accurate information about your age, weight, and height. This data is used to calculate calorie burn and other metrics. Inaccurate information will lead to inaccurate results.

Pay attention to your “Active Zone Minutes.” Fitbit awards these minutes based on your heart rate zones. At altitude, your heart rate zones will be different than at sea level. You might find yourself racking up Active Zone Minutes just by walking uphill. Adjust your expectations accordingly. Don’t push yourself too hard based solely on what your Fitbit tells you. Listen to your body.

Troubleshooting is key. If you’re consistently seeing unusually high heart rate readings, try tightening or loosening your Fitbit band. Make sure the sensor is making good contact with your skin. Clean the sensor regularly to remove sweat and dirt.

Compare your Fitbit’s readings to other wearables. If you have access to a different fitness tracker or even a traditional heart rate monitor, compare the readings during the same activity. This can help you identify discrepancies and understand the extent of the Fitbit’s inaccuracies.

Consider the specific environment. Are you hiking in the Wasatch Mountains? The altitude will be significantly higher than in downtown Salt Lake City. Adjust your expectations and pacing accordingly.

One pitfall is relying solely on your Fitbit for training. While it’s a useful tool, it’s not a substitute for listening to your body and consulting with a healthcare professional or certified trainer. They can help you develop a training plan that’s appropriate for your fitness level and the altitude.

Another common mistake is ignoring the symptoms of altitude sickness. If you experience headache, nausea, dizziness, or shortness of breath, stop exercising and seek medical attention. Your Fitbit can’t detect altitude sickness, so it’s crucial to be aware of the symptoms.

Let’s compare Fitbit performance to other wearables in Salt Lake City. Studies have shown that chest strap heart rate monitors are consistently more accurate than wrist-based trackers at altitude. Brands like Polar and Garmin, known for their focus on athletic performance, often incorporate more sophisticated algorithms to compensate for altitude changes. While Fitbits are convenient, they may not be the best choice for serious athletes training at high altitude.

Real-world application: Imagine you’re training for the Salt Lake City Marathon. Don’t rely solely on your Fitbit to track your progress. Use a chest strap heart rate monitor for accurate data during your long runs. Calibrate your stride length on the course to account for the hills. And most importantly, listen to your body and adjust your pace as needed.

Here’s a step-by-step guide to calibrating your stride length:

Find a flat, measured distance (e.g., a 400-meter track).
Walk or run the distance at your normal pace.
Count your steps.
Repeat steps 2 and 3 several times.
Calculate your average stride length: (Total Distance) / (Total Steps).
Open the Fitbit app.
Go to Account > Activity & Wellness > Exercise.
Tap “Stride Length.”
Enter your calculated stride length for walking and running.

Remember, your Fitbit is a tool, not a guru. Use it wisely, understand its limitations, and adjust your expectations for the unique challenges of living and exercising in Salt Lake City. By taking these steps, you can get more accurate data and make the most of your fitness journey, even at altitude.