Taos Treadmills: Altitude Lies About Heart Health?

By Franklin Everett Shaw

January 4, 2026

Forget the StairMaster. Forget the Peloton. If you’re hitting the treadmill in Taos, New Mexico, or even just visiting, you’re in for a different kind of workout. It’s not just about the incline or the speed; it’s about the air, or rather, the lack of it.

Taos sits at a lung-busting 6,969 feet above sea level. That thin air dramatically alters how your body responds to exercise, especially on a treadmill where you’re not moving through the air as you would outdoors. This isn’t some abstract physiology lesson; it’s a practical guide to keeping your heart rate in check and avoiding altitude sickness while getting your sweat on.

The problem is simple: less oxygen. At higher altitudes, the partial pressure of oxygen in the air is lower. This means each breath you take delivers less oxygen to your bloodstream. Your heart has to work harder to pump the same amount of oxygen to your muscles.

So, what does this mean for your treadmill workout? Your heart rate will be higher at any given intensity compared to sea level. A pace that feels easy in Dallas, Texas, might have your heart pounding in Taos.

Here’s the crucial point: your target heart rate zones need adjustment. Don’t blindly follow the formulas you’ve always used. Those formulas are based on averages, and they don’t account for altitude.

Let’s get specific. A common formula for maximum heart rate is 220 minus your age. For a 40-year-old, that’s 180 bpm. A typical target heart rate for moderate exercise (50-70% of max) would be 90-126 bpm. In Taos, that range is likely too high, especially when you first arrive.

Instead of relying solely on formulas, pay attention to your perceived exertion. This is how hard you feel you’re working. The Borg Rating of Perceived Exertion (RPE) scale is a useful tool. It ranges from 6 (no exertion at all) to 20 (maximal exertion). Aim for an RPE of 12-14 for moderate exercise – “somewhat hard.”

Here’s a step-by-step approach to adjusting your treadmill workouts in Taos (or any high-altitude location like Denver, Colorado, or Flagstaff, Arizona):

1. Acclimatize: Give your body time to adjust. Spend a few days at the altitude before starting intense workouts. Light walks are fine.
2. Start Slow: Reduce your usual treadmill speed and incline. Seriously, dial it back.
3. Monitor Your Heart Rate: Use a heart rate monitor (chest strap is more accurate than wrist-based) to track your heart rate at the reduced intensity.
4. Focus on RPE: Pay close attention to how you feel. If you’re gasping for air and feel like you’re pushing too hard, you probably are.
5. Adjust Accordingly: Gradually increase the intensity (speed or incline) until you reach your target RPE (12-14 for moderate exercise). Note the heart rate at that RPE. This is your new, altitude-adjusted target heart rate for moderate exercise.
6. Hydrate: Drink plenty of water. Altitude increases fluid loss.
7. Listen to Your Body: If you experience symptoms of altitude sickness (headache, nausea, dizziness), stop exercising and descend to a lower altitude if possible.

Let’s consider a case study. Sarah, a 35-year-old runner from Chicago, visits Taos for a ski trip. She’s used to running 5 miles at a 7:30 pace on her treadmill. On her first day in Taos, she tries the same workout. Within minutes, her heart rate is spiking above 180 bpm, and she feels dizzy. She stops immediately.

The next day, Sarah tries again, but this time she starts with a brisk walk at 3.0 mph. Her heart rate is around 120 bpm, and her RPE is about 10 (“very light”). She gradually increases the speed until her RPE reaches 13 (“somewhat hard”). At that point, her heart rate is around 150 bpm, and her speed is only 5.5 mph – significantly slower than her usual pace. She completes a shorter, less intense workout, focusing on maintaining that RPE. Over the next few days, she gradually increases her speed and incline as her body acclimatizes.

A common pitfall is pushing too hard too soon. Many people, especially those who are already fit, underestimate the impact of altitude. They try to maintain their usual workout intensity, leading to excessive heart rates, fatigue, and even altitude sickness.

Another mistake is relying solely on treadmill metrics. Treadmill calorie estimations are notoriously inaccurate, and they don’t account for the increased energy expenditure at altitude. Focus on heart rate and RPE instead.

Furthermore, different treadmill models can display slightly different heart rate readings. If you’re using a treadmill at a hotel or gym, compare the readings to your own heart rate monitor to ensure accuracy.

For residents of high-altitude cities like Denver or Flagstaff, these adjustments become a way of life. They learn to understand their bodies’ responses to altitude and adjust their training accordingly. They also understand that their performance at altitude will likely be slower than at sea level. This is normal and shouldn’t be a source of frustration.

Finally, consider consulting with a healthcare professional or a certified personal trainer experienced in high-altitude training. They can provide personalized guidance based on your individual fitness level and health conditions.

Don’t let the altitude intimidate you. With a little knowledge and careful planning, you can enjoy safe and effective treadmill workouts in Taos, Denver, Flagstaff, or any other high-altitude location. Just remember to listen to your body, adjust your expectations, and breathe.