What inputs go into a readiness score?

Most readiness scores combine four main signals: heart-rate variability (HRV), resting heart rate, sleep quality and duration, and recent training load. Each is compared to your personal baseline rather than to population averages.

How should I act on a low readiness score?

A low readiness score is a signal to reduce intensity or volume, prioritize sleep and recovery, and watch for trends over several days rather than reacting to a single number. It is informational and is not a medical diagnosis.

What Is a Readiness Score? HRV, Sleep & Training Load Explained

Q: What is a readiness score?

A readiness score is a single 0–100 number that estimates how recovered and prepared your body is to take on stress today. It is typically calculated by comparing today's heart-rate variability (HRV), resting heart rate, sleep, and recent training load against your own personal baseline.

What a readiness score actually measures

Rather than a medical diagnosis, a readiness score is a daily summary of recovery signals. The core idea is comparison against your baseline: today's data is weighed against your typical range, so the score reflects change relative to your normal rather than how you compare to anyone else. Because nervous-system recovery and population norms vary widely, individualized baselines tend to be more meaningful than fixed thresholds.

Heart-rate variability is one of the most studied inputs. A 2020 meta-analysis in Frontiers in Physiology reported that resting HRV is responsive to training and recovery status across athletic populations, which is part of why wearables lean on it so heavily. Expert consensus is that no single metric is decisive — readiness is most useful when it combines several signals and is read as a trend.

The four core inputs

Most readiness models, including the one in Reps, combine four recovery signals. Each is summarized below with a real-world source so you can dig deeper.

Autonomic balance

Heart-rate variability (HRV)

HRV is the beat-to-beat variation in your heart rhythm and reflects the balance of your autonomic nervous system. Higher HRV relative to your own baseline generally tracks with a more recovered, parasympathetic state, while a sustained drop can accompany accumulated stress or fatigue.

A 2019 systematic review in Sports Medicine found that HRV-guided training led to similar or better fitness outcomes than predefined plans in most studies reviewed. Sports Medicine (2019)

Recovery trend

Resting heart rate (RHR)

Resting heart rate is your heart rate at rest, usually measured overnight or on waking. An elevated RHR versus your normal range can accompany incomplete recovery, illness, or high stress, so it is most useful as a multi-day trend rather than a single reading.

Large cohort research links a lower resting heart rate with better cardiovascular fitness, making personal RHR trends a useful recovery signal. Journal of the American Heart Association

Restoration

Sleep

Both how long and how well you sleep shape next-day readiness. Deep and REM sleep support physical and cognitive recovery, so short or fragmented nights tend to pull a readiness score down.

The American Academy of Sleep Medicine and Sleep Research Society recommend adults regularly sleep 7 or more hours per night to support optimal health. AASM / Sleep Research Society consensus

Accumulated stress

Training load

Training load captures how much physical stress you have recently absorbed. Readiness models weigh recent hard sessions against your longer-term fitness, so a spike in load without enough recovery can lower your score the following day.

Sports-science research on the acute:chronic workload ratio associates rapid spikes in training load with higher injury risk, underscoring why load is part of readiness. British Journal of Sports Medicine

How to act on your readiness score

A score is only useful if it changes a decision. Exact bands differ between products, but the practical guidance below maps a typical 0–100 scale to how you might adjust a session. These are general training principles, not personalized prescriptions.

High (≈70–100)

A green light to pursue intensity. If your goals call for it, this is a reasonable day for harder intervals, heavier lifts, or longer sessions — while still listening to how you actually feel.

Moderate (≈40–69)

A signal to train with awareness. Consider keeping intensity moderate, trimming volume, or favoring technique and easy aerobic work over maximal efforts.

Low (≈0–39)

A nudge toward recovery. Prioritize sleep, hydration, and lighter movement, and treat a persistent low trend — not one off day — as the meaningful signal.

Read the trend, not the day

Any single morning can be skewed by a late meal, alcohol, travel, or a noisy measurement. Coaches and sports scientists generally advise watching a 3–7 day direction of travel and pairing the number with how you subjectively feel before making big changes to a plan.

Not medical advice

A readiness score is an informational wellness estimate, not a medical device or diagnosis. Individual physiology varies, and the relationships described here are general tendencies rather than guarantees. Consult a qualified healthcare or medical professional before making decisions about training, recovery, or any symptom — especially if a metric changes sharply or you feel unwell.

See your own readiness score

Reps is an AI recovery & training coach that turns your HRV, sleep, and training load into a daily readiness score and adaptive plan. If you already track HRV and sleep with Apple Health, Reps can turn that data into a daily score and a plan that adapts to it — no extra hardware required.

Download Reps on the App Store