**Dark Skin, Denver Devices: Altitude Lies Stealing Data?**

By Franklin Everett Shaw

November 10, 2025

It’s easy to assume that the sleek, colorful fitness tracker on your wrist is giving you accurate data. But what if that data isn’t accurate for everyone? And what if where you live – say, Denver, Colorado – makes the problem even worse?

Here’s the uncomfortable truth: wearable fitness trackers, especially those relying on optical sensors, can struggle with accuracy for individuals with darker skin tones, and Denver’s high altitude adds another layer of complexity. Let’s dive into why this happens and, more importantly, what you can do about it.

The culprit behind the inaccuracy often lies in the technology used to measure heart rate and blood oxygen saturation (SpO2). Many wearable devices use photoplethysmography (PPG), which shines green light onto the skin and measures the amount of light reflected back. The sensor then interprets these light variations to estimate heart rate and blood oxygen levels.

Melanin, the pigment responsible for skin color, absorbs light. Higher levels of melanin, common in individuals with darker skin tones, can absorb a significant portion of the green light emitted by the sensor. This reduces the amount of light reflected back to the sensor, making it harder to get an accurate reading. Think of it like trying to see clearly through tinted glass – the darker the tint, the harder it is to see.

Now, let’s throw Denver’s altitude into the mix. At 5,280 feet (one mile high), the air is thinner, meaning there’s less oxygen available. This lower oxygen saturation can already be a challenge for wearable sensors to accurately detect. Combine that with the melanin issue, and you’ve got a recipe for potentially unreliable data.

So, what does this mean for a Denver resident with darker skin who’s trying to track their fitness? It means you might be getting inaccurate readings, especially during exercise when your heart rate and breathing rate increase. This could lead to misinterpretations of your workout intensity, calorie burn, and overall fitness progress.

Here’s a concrete example: Imagine two individuals, one with lighter skin and one with darker skin, both running the same route in City Park. Both are wearing the same model of fitness tracker. The individual with lighter skin might see a heart rate reading that accurately reflects their exertion level. The individual with darker skin, however, might see a lower heart rate reading, leading them to believe they aren’t working as hard as they actually are. This could lead to overexertion or a less effective workout.

But don’t despair! There are steps you can take to improve the accuracy of your wearable fitness tracker in Denver, even with darker skin.

First, experiment with different placement. Try wearing the device higher up on your wrist, or even on the inside of your wrist, where the skin might be slightly thinner and less pigmented. Tighten the band to ensure good contact between the sensor and your skin, but not so tight that it restricts blood flow.

Second, consider alternative sensor settings. Some devices allow you to adjust the sensor sensitivity or switch to different wavelengths of light. While green light is commonly used, some devices also incorporate red or infrared light, which might be less affected by melanin. Check your device’s manual or app settings to see if these options are available.

Third, supplement your data with other measurement methods. Don’t rely solely on your wearable device. Use a chest strap heart rate monitor, which uses electrical signals to measure heart rate and is generally more accurate than optical sensors. You can also manually check your pulse using your fingers and a stopwatch.

Fourth, be aware of specific Denver-area brands and their performance. While there isn’t extensive research specifically on Denver-area brands, it’s worth noting that some brands are known to perform better than others in diverse skin tones. Look for reviews and comparisons that specifically address this issue. Fitbit, for example, has faced scrutiny in the past regarding accuracy across different skin tones, while Apple has made efforts to improve its sensor technology.

Fifth, advocate for inclusive device design. As consumers, we have the power to demand better. Contact wearable device manufacturers and express your concerns about accuracy issues for individuals with darker skin tones. Encourage them to invest in research and development to create more inclusive and equitable devices. Share your experiences on social media and online forums to raise awareness and hold companies accountable.

A common pitfall developers face is relying on datasets that are not representative of the population. This can lead to biased algorithms and inaccurate sensor readings for certain groups. To overcome this, developers need to prioritize diverse data collection and testing. This means including individuals with a wide range of skin tones, ages, and fitness levels in their research studies.

Another challenge is the assumption that one-size-fits-all calibration works for everyone. In reality, individual factors like skin hydration, body fat percentage, and even ambient temperature can affect sensor readings. Developers should explore personalized calibration methods that take these factors into account.

Here’s a step-by-step guide to advocating for inclusive device design:

1. Research: Identify wearable device manufacturers that have a history of addressing diversity and inclusion in their product development.
2. Contact: Reach out to these companies through their customer service channels, social media platforms, or investor relations departments.
3. Express your concerns: Clearly and respectfully explain the accuracy issues you’ve experienced with their devices, highlighting the impact on your fitness tracking and overall health.
4. Provide evidence: Share any relevant research articles, personal anecdotes, or data comparisons that support your claims.
5. Suggest solutions: Offer concrete suggestions for improvement, such as investing in diverse data collection, developing personalized calibration methods, or incorporating alternative sensor technologies.
6. Amplify your voice: Share your experiences and advocacy efforts on social media and online forums to raise awareness and encourage others to join the cause.

Remember, achieving accurate fitness tracking for everyone is not just a matter of technological advancement; it’s a matter of equity and inclusion. By understanding the limitations of current wearable devices and taking proactive steps to improve data accuracy, Denver residents with darker skin can take control of their fitness journey and advocate for a more inclusive future. Don’t just accept the data at face value – question it, challenge it, and demand better. Your health and well-being depend on it.