Sleep data for coaches

The three numbers, in order of usefulness

Most sleep interfaces present these with equal weight. They do not deserve it.

Duration — trust it, act on it

Total time asleep is the one sleep metric that is both measured accurately by consumer hardware and directly changeable by the athlete. If you only look at one thing, look at this.

Consistency — trust it, coach it

How much bed and wake times move night to night. Slow to change, rarely displayed prominently, and frequently the underlying explanation for an athlete whose HRV series looks like noise.

Stages — treat as directional

Deep, REM and light breakdowns from a wrist or ring device are estimates inferred from movement and heart rate, not measurements. Useful as a rough trend within one athlete on one device; not worth a coaching decision on their own.

Why duration beats the sleep score

Most devices fold duration, timing, stages and disturbances into a single sleep score. That is a reasonable thing to show the wearer and a poor thing to coach from, because it obscures the one component you can actually do something about.

An athlete sleeping six hours has a specific, addressable problem. An athlete with a sleep score of 62 has a number. The first conversation goes somewhere; the second usually does not.

There is also a floor effect worth knowing: below roughly six hours, most other recovery signals degrade too, so a low HRV reading on the back of a short night is usually a sleep observation rather than a training one.

What to do when sleep drops

Establish whether it is one night or a pattern

A single short night is a normal part of being alive. Three or four across a week is a different conversation, and the second is far more likely to show up in performance.

Ask about timing before quantity

Athletes who cannot get more hours can often get more regular hours, and consistency is frequently the easier win.

Check what changed around it

Travel, a schedule change, a new baby, exam season, a late training slot. Most sustained sleep drops have a mundane cause the athlete can name immediately.

Be careful about adding pressure

Athletes who become anxious about their sleep score sometimes sleep worse. Frame it as a lever they control rather than a score they are failing.

The limit

Frequently asked

How much sleep should my athletes get?

General guidance for adults sits around seven to nine hours, with many athletes in hard training feeling better at the upper end. Treat that as context rather than a target to enforce — the useful comparison is against what that individual normally gets.

Are sleep stage measurements from a watch accurate?

They are estimates inferred from movement and heart rate rather than direct measurements, so treat them as directional. Duration and consistency are the numbers solid enough to coach on.

Should I look at sleep score or sleep hours?

Hours, plus consistency. The composite score can be a useful glance for the athlete, but it hides which component moved and the component is what you would actually act on.