I used to think sleep trackers were just expensive ways to confirm what I already knew — that I wasn’t sleeping enough. A few years ago, that was a fair assessment. But the technology has moved on, and some of it is genuinely useful now. Other bits? Still mostly marketing.

How We Got Here

The first consumer sleep trackers tracked movement and called it sleep data. If you were lying still, the app assumed you were asleep. It was barely better than guessing.

Second-generation trackers added optical heart rate sensors, which helped differentiate sleep stages. This was a real improvement, but accuracy studies in the Journal of Clinical Sleep Medicine consistently showed these devices overestimated total sleep time and struggled to identify wake periods.

The current generation combines heart rate variability, skin temperature, blood oxygen, respiratory rate, and in some cases EEG signals. The accuracy gap between consumer devices and clinical polysomnography has narrowed considerably — though it hasn’t closed.

What the Research Supports

Oura Ring (Gen 4) has the strongest independent research base of any consumer tracker. Studies show its sleep staging accuracy at around 79% agreement with polysomnography, which is impressive for a ring. Its readiness score — combining sleep quality, HRV, and temperature data — has shown meaningful correlation with self-reported energy levels. I wear one, and it’s the most useful sleep tool I’ve owned.

WHOOP 5.0 takes a similar approach but excels with its strain-recovery framework, contextualising sleep against physical activity. The Australian Institute of Sport has used WHOOP data in athlete recovery protocols, which speaks to its reliability.

Under-mattress sensors like the Withings Sleep Analyzer deserve more attention. Because they don’t need to be worn, compliance is perfect. Their respiratory disturbance detection has been clinically validated, meaning they can flag potential sleep apnoea — important given an estimated 9% of Australian adults have undiagnosed sleep apnoea according to the Sleep Health Foundation.

Smart alarm features — waking you during light sleep within a set window — have decent evidence behind them. A 2025 meta-analysis found light-sleep-phase alarms were associated with improved subjective alertness on waking. Not dramatic, but real.

What Doesn’t Work

Smartphone-only sleep apps. If you’re tracking sleep through your phone’s microphone on the mattress, the data is largely unreliable. These apps can estimate time in bed, but they can’t meaningfully assess sleep stages. They’re entertainment, not health tools.

Sleep scores as absolute measures. Every tracker gives you a score out of 100, and people fixate on it. These scores are proprietary and calculated differently by every manufacturer. A “78” on Oura doesn’t mean the same thing as a “78” on Fitbit. Use them for tracking your own trends, not as an objective grade.

“Orthosomnia” is a real term coined by researchers for people who become so anxious about their sleep data that it worsens their sleep. If checking your score first thing every morning makes you stressed, the tracker is doing more harm than good. I’ve seen friends get genuinely upset about a “bad” score on nights they felt fine. Trust your body alongside the data.

What Actually Improves Sleep

Here’s the irony: the most effective sleep interventions don’t require technology.

Consistent sleep and wake times remain the single most impactful change. Your circadian rhythm doesn’t care about your weekend plans. Going to bed and waking up within a 30-minute window every day makes more difference than any gadget.

Temperature management is underrated. Evidence is clear that a cooler sleep environment (around 18-19 degrees) promotes better sleep. A good fan will likely do more than a $500 wearable.

Light exposure timing. Bright light within the first hour of waking, and reduced blue light after sunset, has strong evidence for improving sleep onset and quality. It’s free.

CBT-I is more effective than sleeping pills for chronic insomnia, with effects that persist after treatment ends. It’s available through some Australian GPs and psychologists, and digital programs like Sleepio have decent evidence behind them.

My Take

If you can afford it, a quality wearable like Oura or WHOOP provides genuinely useful data — especially for spotting trends you’d miss subjectively. If your tracker shows your HRV tanks every time you drink alcohol, that’s useful feedback worth having.

But the tracker itself won’t improve your sleep. It’s a mirror, not a medicine. The changes that actually matter are behavioural — and most of them are free.

Start with the basics. Track if you want to. But don’t let the data become another source of stress in a life that probably has enough of that already.