From Apple Watches and Garmins to Oura rings and Whoop straps, wearable tech is everywhere in gyms across St Albans and Harpenden. Most driven individuals now track almost every possible metric:

  • Daily steps
  • Hours slept
  • Calories burned
  • Heart rate
  • Morning recovery and readiness scores

Having access to this much information is incredible. But it raises a serious question: Are these devices actually improving our health, or are they just making people overthink everything?

What Fitness Trackers Do Well

When used correctly, wearable tech is a fantastic tool for hybrid athletes and everyday gym-goers alike. A fitness tracker’s biggest strength is keeping you accountable. Seeing your daily activity levels laid out on a screen can encourage more movement, improve your overall awareness, and help you build long-term consistency.

Fitness trackers are also excellent for spotting long-term trends. Watching your resting heart rate drop or your heart rate variability (HRV) slowly increase over a few months is a great indicator that your cardiovascular fitness is improving. Furthermore, if you are incorporating hybrid training routines, a watch is incredibly useful for pacing your cardio and keeping you in the correct heart rate zones during easy runs or rides.

The Downsides

While the data can be helpful, the dark side of wearable tech is the obsession it can create. Instead of feeling empowered, many people develop anxiety around their sleep or recovery scores. Researchers from Rush University Medical Center even coined the term “orthosomnia” to describe the growing phenomenon of patients experiencing worsened sleep due to a perfectionistic, anxious preoccupation with their wearable sleep data (Baron et al., 2017).

It is becoming increasingly common to see athletes ignore how their body actually feels in favour of what a screen tells them. You might wake up feeling refreshed and ready to tackle a heavy lifting session, only to see a “red” recovery score on your watch. Suddenly, you feel sluggish and decide to skip your training entirely because the watch says your recovery is “low.”

Some people now let their watch decide how they should feel.

This over-reliance on data leads to inaccurate self-assessments. It causes people to constantly stress over imperfect sleep scores or fixate on calorie tracking to dictate their daily meals. A recent study published in SLEEP found that over 30% of adults who track their sleep report symptoms of orthosomnia, feeling nervous or on edge about the metrics they receive (Weaver et al., 2026). When you stop listening to your body’s natural signals, you lose the intuitive awareness required to truly excel in functional fitness.

Are They Accurate?

If you are going to let a piece of technology influence your training, it is important to know how accuracy actually measures up in the real world. When looking at the data, the reality is a mixed bag:

  • Heart rate tracking: Wrist-based optical sensors are usually decent for steady-state cardio. A landmark study from Stanford University found that six out of seven popular fitness trackers measured heart rate with an error rate of less than 5% during steady exercise (Shcherbina et al., 2017). However, during high-intensity interval training or heavy lifting, rapid arm movements and muscle contractions make them far less reliable.
  • Calorie estimates: Generally speaking, calorie tracking is notoriously inaccurate. The same Stanford University study revealed that none of the tested devices accurately measured energy expenditure, with the most accurate device still off by an average of 27%, and the least accurate off by a staggering 93% (Shcherbina et al., 2017). They rely on generic algorithms that cannot account for your unique metabolic efficiency or muscle mass.
  • Sleep tracking: Your device is highly accurate at detecting whether you are asleep or awake. However, sleep tracking is only an estimate when it comes to specific sleep stages. According to a validation study of commercial wearables, these devices typically have high sensitivity for detecting when you are asleep (over 90%) but demonstrate significantly lower specificity (29% to 52%) when detecting wakefulness, frequently causing them to overestimate total sleep time and misclassify deep or REM sleep stages (Aubert et al., 2024).
  • Recovery scores: Readiness scores are a helpful combination of your HRV, sleep, and activity, but they remain imperfect. They cannot measure muscle soreness, central nervous system fatigue, or psychological readiness.

The strong takeaway here is that fitness trackers are best used for spotting long-term trends, not providing exact, undeniable answers.

Who Benefits Most?

Fitness trackers can be especially helpful for:

  • Beginners trying to build consistency
  • Runners/endurance athletes
  • People increasing their daily activity
  • Those wanting accountability

They may be less helpful for:

  • Highly anxious personalities
  • People already obsessed with numbers
  • Anyone ignoring basic habits like sleep and nutrition

Practical Tips

Three simple ways to use fitness trackers better:

  1. Focus on long-term trends, not daily fluctuations
  2. Don’t rely on calorie burn estimates
  3. Combine data with how you actually feel

Learn to Trust Your Body Again

Fitness trackers can support healthier habits, but they should guide decisions rather than control them. The best approach is still combining useful data with common sense and genuine body awareness. If you feel great, do not let a low recovery score hold you back. If your joints ache and you feel exhausted, do not push through a brutal workout just because your watch says you are primed to train.

Transform Your Everyday Performance With Personalised Coaching

If you are tired of overthinking your metrics and want to build true resilience, we are here to guide you. Work with a dedicated functional fitness coach in St Albans to create a practical, sustainable plan tailored to your life and how your body actually feels. At Conroy Performance, we focus on real-world strength and hybrid fitness, helping you move past the numbers and build lasting confidence. Have questions or want to book a first session? Simply contact us, and we will help you get started. The healthiest people are usually the ones who use technology to support their habits, not control them.

References

Aubert, X., et al. (2024). A performance validation of six commercial wrist-worn wearable sleep-tracking devices for sleep stage scoring compared to polysomnography. Nature and Science of Sleep, 16, 123-138.

Baron, K. G., Abbott, S., Jao, N., Manalo, N., & Mullen, R. (2017). Orthosomnia: Are Some Patients Taking the Quantified Self Too Far? Journal of Clinical Sleep Medicine, 13(2), 351-354.

Shcherbina, A., Mattsson, C. M., Waggott, D., Salisbury, H., Christle, J. W., Hastie, T., Wheeler, M. T., & Ashley, E. A. (2017). Accuracy in Wrist-Worn, Sensor-Based Measurements of Heart Rate and Energy Expenditure in a Diverse Cohort. Journal of Personalized Medicine, 7(2), 3.Weaver, M. D., et al. (2026). 0553 Exploring the Prevalence of Sleep Tracking and Orthosomnia in a National Survey of Adults in the US. SLEEP, Volume 49, Supplement 1.