Denver's Fitness Trackers: High Altitude, Low Accuracy?
By Franklin Everett ShawAre you really getting an accurate read on your fitness in Denver? Your fancy fitness tracker might be lying to you, especially if you’re relying on its default settings. The Mile High City presents unique challenges to these devices, primarily due to its altitude and the resulting lower barometric pressure.
This isn’t just about bragging rights on Strava; inaccurate data can impact your training, your health, and even your motivation. Let’s dive into how to make your Fitbit, Garmin, or Apple Watch a reliable training partner in Denver.
Barometric pressure is the key culprit. Most fitness trackers use a barometric altimeter to estimate elevation changes. Lower air pressure at higher altitudes fools the device into thinking you’ve climbed more than you actually have. This leads to inflated elevation gain, calorie burn estimates, and even inaccurate distance tracking.
Think of it this way: your tracker is designed for sea level. In Denver, it’s constantly trying to correct for a “climb” that doesn’t exist.
So, what can you do? First, understand that no tracker is perfect. They all rely on algorithms and estimations. However, you can significantly improve accuracy with proper calibration and supplemental data.
Let’s start with calibration.
Fitbit: Fitbit devices often calibrate automatically using GPS. However, in Denver, this can be unreliable due to GPS signal interference from buildings and terrain. Manually calibrate your Fitbit by syncing it near a known elevation point. Use a reliable source like a USGS benchmark or a building with a clearly marked floor number and known elevation. Sync your Fitbit immediately after being at that location. Repeat this process regularly, especially after traveling to lower altitudes.
Garmin: Garmin offers more robust calibration options. Use the Garmin Connect app or website to manually enter your current elevation. You can also enable the “Continuous Calibration” feature, which uses GPS to automatically adjust the altimeter. However, as with Fitbit, be mindful of GPS accuracy in Denver. Consider using a Garmin device with a built-in DEM (Digital Elevation Model) map for more accurate elevation data. These models use pre-loaded topographical data to improve accuracy, even without a strong GPS signal.
Apple Watch: Apple Watch relies heavily on GPS for elevation data. Ensure your watch has a clear view of the sky during workouts. Calibrate your Apple Watch by using the Workout app and selecting an outdoor activity like running or walking. After a few minutes, the watch will use GPS to estimate your elevation. You can also use third-party apps like “Altimeter+” to manually calibrate your watch.
Beyond calibration, consider these supplemental data sources:
USGS Topo Maps: The United States Geological Survey (USGS) provides detailed topographic maps that show elevation contours. Use these maps to verify the elevation gain reported by your tracker. You can find these maps online or at local outdoor retailers like REI in Denver.
Denver Parks and Recreation Data: Denver Parks and Recreation often publishes trail maps with elevation profiles. Compare these profiles to the data recorded by your tracker to identify discrepancies.
Strava Segment Analysis: Strava segments provide a community-driven way to compare your performance on specific routes. Analyze your elevation data on Strava segments to see how it compares to other users. If your tracker consistently overestimates elevation gain, you’ll likely see discrepancies in your Strava data.
Common Pitfalls and How to Avoid Them:
Relying solely on GPS: GPS signals can be weak in urban canyons and mountainous terrain. Don’t rely solely on GPS for elevation data. Use a combination of GPS, barometric altimeter, and supplemental data sources.
Ignoring weather conditions: Barometric pressure changes with weather patterns. A sudden drop in pressure can trick your tracker into thinking you’ve climbed higher than you actually have. Be aware of weather conditions and adjust your expectations accordingly.
Not calibrating regularly: Barometric altimeters drift over time. Calibrate your tracker regularly, especially after traveling or experiencing significant weather changes.
Comparing data between different devices: Different trackers use different algorithms and sensors. Don’t expect perfect agreement between different devices. Focus on tracking trends over time with a single device.
Real-World Scenarios:
Red Rocks Amphitheatre: Running the stairs at Red Rocks is a popular workout in Denver. Your tracker will likely overestimate the elevation gain due to the steep incline and the already high altitude. Use a USGS topo map to verify the actual elevation gain.
Cherry Creek Trail: The Cherry Creek Trail is relatively flat, but your tracker may still report some elevation gain due to barometric pressure fluctuations. Pay attention to the overall trend of your elevation data rather than focusing on small variations.
Hiking in the Foothills: Hiking in the foothills west of Denver presents the biggest challenge for fitness trackers. The combination of high altitude, steep terrain, and GPS signal interference can lead to significant inaccuracies. Use a Garmin device with a DEM map and supplement your data with USGS topo maps.
Actionable Insights:
Create a calibration routine: Set a reminder to calibrate your tracker at least once a week. Choose a known elevation point near your home or workplace.
Use a data logging app: Use a data logging app like “GPS Logger” to record your GPS coordinates and elevation data independently of your fitness tracker. This can provide a baseline for comparison.
Experiment with different settings: Experiment with different calibration settings on your tracker to see which ones provide the most accurate data in your specific environment.
Don’t get discouraged: Fitness trackers are tools, not oracles. Don’t get discouraged if your data isn’t perfect. Focus on using the data to track your progress and make informed decisions about your training.
Living and training in Denver requires a different approach to fitness tracking. By understanding the limitations of your device and using the techniques outlined above, you can get a more accurate picture of your fitness and achieve your goals. Remember, knowledge is power, especially at altitude.