Your HRV Score Is Lying to You (Kind Of)

Open any Garmin, Oura, or Whoop app in the morning and there's a number waiting for you: your HRV. It's presented with enough confidence that it's easy to assume it's a precise verdict on how your day should go. It isn't quite that — but it also isn't nothing.

What HRV Actually Measures

Heart rate variability is the tiny, natural variation in the time between consecutive heartbeats. Counterintuitively, *more* variation is generally the good sign — it reflects a nervous system that can flexibly shift between "go" (sympathetic) and "rest and digest" (parasympathetic) states. Chronic stress, poor sleep, illness, alcohol, and accumulated training fatigue all tend to suppress it.

The key thing to understand: there's no universal "good" HRV number. Values vary hugely between individuals based on age, fitness, and even how a device measures it. What matters isn't the raw number — it's your own trend relative to your personal baseline.

How the Big Platforms Present It

• Garmin builds HRV into its Training Readiness score: it measures HRV overnight, compares it against your rolling baseline, and folds it into a single daily readiness number alongside sleep and training load.
• Whoop centers its entire platform around HRV and "Recovery" — a color-coded daily score (green/yellow/red) meant to guide same-day training intensity.
• Oura frames HRV alongside its Readiness Score, with a particular emphasis on overnight trend graphs rather than a single snapshot.

All three are measuring roughly the same underlying signal; they differ mainly in how much interpretation they layer on top of it.

The Practical Rule: Trend, Not Snapshot

A single low reading on one morning tells you very little — normal day-to-day variation, a late dinner, or a rough night's sleep can all move the number without meaning anything about your training capacity. What's genuinely useful is a *sustained* drop below your personal baseline over several consecutive days. That pattern is a more reliable signal that recovery is lagging behind training load — worth easing off before it turns into a harder crash.

Consistency in *how* you measure also matters more than people expect: take readings at the same time, in the same position (most platforms recommend overnight, sleeping HRV rather than a spot-check standing up), and avoid drawing conclusions from a single night after travel, alcohol, or illness — those will move HRV regardless of training status.

Where It Falls Short

HRV is one input, not a verdict. Rate of perceived exertion, how your legs actually feel in a warm-up, and simple session-to-session performance trends are all still worth trusting alongside — or sometimes over — a wearable's number. Treating a single "red" recovery score as a hard stop can be just as unhelpful as ignoring HRV altogether.

Daily Chore Take

For a hobby athlete training for a HYROX, a marathon, or a Gravel weekend, HRV is worth having on in the background — not as a daily command, but as an early warning system for the kind of accumulated fatigue that's hard to feel day-to-day but shows up clearly over a week. Watch the trend, not the number.

*This article discusses general wellness and training concepts and isn't medical advice. If you have concerns about your heart health, talk to a doctor.*