Is Data Hurting Your Running?

Modern runners have access to more data than ever before. GPS watches, fitness scores, and social feeds promise smarter training, but for many runners, all this information is quietly doing the opposite.

As a running-focused physical therapist and running coach in Boston, I see this pattern constantly: runners think they’re training effectively, yet feel stuck, burned out, or injured. Not because they lack discipline, but because technology is driving their decisions instead of supporting them.

Too much data, not enough clarity

I’m not anti-data. I use data daily with my patients and clients. But I’m very particular about which data I use and how I use it.

Many runners are drowning in metrics they don’t fully understand, and that are less accurate than they may realize.

Heart rate data from wrist wearables isn’t perfect. Optical sensors on watches can be affected by motion, wrist position, and other factors, especially during harder runs. Not to mention, heart rate zones on watches are often not anchored to a runner’s true max heart rate. This means the zones you’re trusting might not match your actual physiology.

VO₂max estimates from watches are estimates, not lab measurements. Research shows that common wrist-worn devices often miss the mark by more than 10% compared to gold-standard lab assessments, and accuracy varies by device and fitness level.

Race time predictions and “fitness scores” are algorithmic guesses. They’re based on proprietary formulas that use your historical pace and heart rate data, but they can easily be skewed by noise, inaccurate inputs, or inconsistent training. They often over-value high intensity workouts, and knock you for lower intensity runs.

If a metric doesn’t guide a clear decision, it’s not helpful.

Better training doesn’t come from more numbers. It comes from focusing on what matters, knowing how to interpret that information, and making sensible decisions based on it.

What I Do With Runners I Coach and Treat

I often prefer using simpler and, in my opinion, more effective ways of tracking training load, such as the acute-to-chronic workload ratio (ACWR) using basic inputs like time and rate of perceived exertion (RPE). These variables may seem “less advanced,” but they capture something many wearables struggle with: how much work you’re actually doing, and how hard that work feels to you. ACWR doesn’t try to predict fitness or assign a score. Instead, it answers a more practical question: Is your recent training load appropriate relative to what your body has been prepared for over the past several weeks? By focusing on relative changes rather than absolute numbers, it helps identify risky spikes in training and supports more sustainable progression, without relying on noisy or metrics that claim to be precise but, in reality, are not. Put simply, it is an excellent tool to lower the risk of doing too much, too soon. ACWR doesn’t measure fitness directly. Where fitness comes into the picture is how a runner responds to their training. When training is progressing appropriately, we often see the same workload elicit a lower perceived effort over time, or allow a runner to tolerate slightly higher loads at the same RPE. In other words, fitness improvements tend to reveal themselves not through a single "fitness score" or prediction, but through improved efficiency and tolerance: runs feel easier, recovery improves, consistency becomes easier to maintain, and we adjust programming to account for these fitness gains. ACWR picks up on this. At Miles Ahead, I have begun to transition the folks I work with to using the Find Your State app, which does an excellent job of measuring ACWR to help inform training decisions.

Let’s talk about Strava

Oh, Strava. A training log with an audience.

At its best, it fosters community. It can be motivating. It can be fun.

At its worst, it can be stressful.

For one, the fitness score and race predictions are not particularly accurate. If you’re judging how your training is going based on that data, you’re probably setting yourself up for frustration.

But the bigger issue I see comes from the social side of the app.

The comparison game is real, and it can be dangerous.

I hear this regularly from runners I work with. The mental load of having training be public takes up real emotional bandwidth. Runners talk about feeling:

• judged for taking easy days or having bad runs

• pressure to explain slow runs

• hesitation to take rest days

• anxiety about how runs “look”

  
  

Meanwhile, their feeds are full of other runners seemingly crushing every workout.

That spiral can be harmful in more than one way.

Runners often assume what they’re seeing reflects good training. Strava removes context, but our brains still treat the information as meaningful. That comparison alone can nudge runners toward overreaching, even when they know better.

I’ve seen runners question solid training plans after seeing friends with similar goals running faster paces, deviate from their programming, and get hurt as a result.

Even if Strava doesn’t change your training decisions, it can still be stressful to consume. And stress matters. Recovery, adaptation, and injury risk are influenced by total load, including mental and emotional stress, not just mileage and workouts. This is a common pattern I see in runners coming to me for physical therapy and coaching.

Using Strava more intentionally

You don’t need to delete Strava to train better. But you should use it intentionally, or consider alternatives.

Some options that work well for runners:

• uploading runs privately

• hiding pace or heart rate data from followers

• muting runners whose training stresses you out

• taking short breaks from sharing

• using apps like Garmin or COROS that collect data without a social feed

• tracking training in a physical journal

  
  

You can still get the benefits of tracking without feeling like you’re performing.

If Strava motivates you and adds joy to your training, great. If it creates stress, comparison, or second-guessing, it’s worth rethinking how you use it.

An unhealthy relationship with training tech can happen to beginners and experienced runners alike.

How Miles Ahead helps runners train smarter

At Miles Ahead Physical Therapy and Performance, I help runners:

• overcome running injuries and return to training toward big goals

• stay healthy through personalized, intentional run coaching

• train with less stress and more clarity

  
  

My work blends physical therapy, strength training, and run coaching to support runners who want to improve without burning out or breaking down.

If you’re a runner in the Boston area dealing with an injury, or you’re looking for a clearer, more sustainable approach to training, you can learn more about working together by setting up a discovery call here.