For Garmin athletes & sleep optimizers

Optimize your Evening.
Maximize your Recovery.

SAYA turns your raw Garmin data into actionable evening routines — showing you exact correlations between habits and real recovery — get ready for peak performance!

Join the waitlist — you'll get your invite plus occasional product updates. No spam, unsubscribe anytime. Privacy

SAYA home dashboard with Readiness score plus Evening, Sleep and Recovery rings and a heart-rate chart SAYA HRV trend chart across the night with an alcohol marker SAYA sleep detail screen with timing, duration, deep/REM cards and a hypnogram SAYA sleep pattern chart showing bedtime consistency over 30 days SAYA correlation screen listing positive drivers and negative impactors for sleep score SAYA correlation detail screen with a scatter plot and trend-over-time chart SAYA evening routine tracking form for logging a meal
Effects of evening habits at one glance Influence of evening habits on recovery Sleep details and targets Identify Pattern Learn what affects your sleep the most Correlation Details Easy Habit Tracking

How it works

Three steps to peak recovery.

01 Garmin integration

Unlocks your Garmin data

Runs automatically in the background. SAYA transforms your raw heart rate and HRV metrics into actionable evening insights.

02 Evening routine

Master your wind-down

Learn how evening body load delays your recovery. Optimize dinner timing, late stress, and habits for lower eRHR.

03 Readiness

Be ready for tomorrow

Build an evidence-backed evening routine that reliably boosts your overnight HRV and morning readiness.

One night with SAYA

Scroll through a real night.

Everything below is live data from one SAYA athlete's Garmin — real curves, real scores, real patterns. Nothing staged.

18:30 · The evening begins

Evening tracking

Log your evening in seconds.

No forms. No journaling guilt. Tap your dinner, wind-down and what kept you wired — done in seconds. Every tap fuels your personal experiment.

Under the hood: meals scored on timing, size & processing (NOVA); wind-down and arousals each scored — one Evening Score.
This evening 21:30
Dinner18:30
Carb
Protein
Balanced
Veggie
CARBS
PROTEIN
FAT
FIBER
NOVA
1 2 3 4
Wind-down
Reading Stretching Breathwork Yoga
Extent
Moderate
Arousals
Social media Mental stress Late work Argument
Intensity
Mild
Blue light · medium
  • Dinner logged
  • Wind-down logged
  • Arousals logged
Evening Score86
22:40 · The last hour before sleep

Evening resting heart rate

One number predicts your night.

Evening resting heart rate — a strong predictor of sleep quality. Read straight from your Garmin, no button pressed. Lower it with easy habits → deeper sleep, better recovery.

This real evening: a late run, dinner at 20:00 and one drink lifted the resting rate to 51 bpm — +6 above the 45 baseline, likely disrupting the first half of the night, and recovery with it.
Evening
51 bpm
+6 bpm
resting window · 20:30–22:30 øRHR 45 bpm 16:30 22:49
  • Caffeine — 2 coffees earlier still linger into the evening
  • Training — your run pushes heart rate to 147 bpm
  • Cool-down — the body takes ~2 h to settle back down
  • Dinner · Digestion — 20:00, then ~2.5 h to digest
  • Alcohol — one drink delays overnight recovery
  • Wind-down — 15 min of stretching before bed

Heart rate settles to 51 bpm in the last 2 h before sleep — +6 above your 45 average.

02:00 · Deep in the night

HRV-Incline analysis

Catch the stress you take to bed.

Take physical strain to bed, and your body has to process that load before real recovery begins. HRV-Incline catches this hidden debt in your first hours of sleep and traces it back to your evening.

One real night, replayed above: HRV climbed from a stressed 25 to a 66 ms plateau — a +40 ms incline over 3.7 h before the body reached deep recovery.
HRV
66 ms
3.7 h · +40 ms
ø 66 ms 23:36 05:41
  • Digestion — dinner still being processed as sleep begins
  • Alcohol — one nightcap still fading as sleep begins
  • Incline — HRV needed 3.7 h to climb +40 ms before recovery settled

HRV-Incline Delta: +40 ms · Incline duration: 3.7 h. The steeper and longer that climb, the more recovery it costs.

06:24 · Morning — the answers arrive

Personal correlations

See what actually moves your sleep.

Auto-metrics — evening resting heart rate, HRV-Incline, sleep timing & duration — analysed from day one, right after login. Habit links learn as you go: use more, learn more. Your positive drivers and negative impactors, side by side.

From 77 real nights: a regular bedtime lifts this athlete's Sleep Score by +26%, while high evening stress costs −13% (p < 0.01).
Sleep Score 71 nights · 90d

Positive drivers

Regular Bedtime+12%
Moderate · p<0.001n=70
Dinner Score+8%
Weak · n.s.n=38
Caffeine Cups+6%
Weak · n.s.n=38
Evening Score+6%
Moderate · p<0.05n=32

Negative impactors

Evening Stress-9%
Moderate · p<0.01n=64
Evening RHR-7%
Moderate · p<0.01n=67
Room Darkness-7%
Weak · n.s.n=38
Alcohol-5%
Strong · p<0.001n=38

Top vs. bottom quarter of your nights · Pearson r, two-tailed p

Correlation detail

The evidence behind every driver.

Every habit, its receipts: night-by-night scatter, trend, and the real stats — strength, effect size, significance, sample size. Check it yourself before you change a thing.

Dinner Score → Sleep Score: r = 0.40, +17% top-vs-bottom quarter, p < 0.05 across 36 nights — a real link.
Dinner Score → Sleep Score Scatter
668297577593 Dinner Score Sleep Score
r 0.65+14%p<0.01R² 42%n 15
Dinner Score → Sleep Score Trend
Jul 1Jul 18Jul 27
Sleep ScoreDinner Score
r 0.65+14%p<0.01R² 42%n 15
Evening RHR → Sleep Score Scatter
6682973676116 Evening RHR Sleep Score
r -0.33-7%p<0.01R² 11%n 67
Evening RHR → Sleep Score Trend
May 8Jun 15Jul 27
Sleep ScoreEvening RHR (inverted)
r -0.33-7%p<0.01R² 11%n 67

Patterns

Your rhythms, made visible.

Based on your sleep quality, SAYA finds your true ideal timings — bedtime, duration, wake, dinner timing and training timing. Reliably calculated, fully traceable. Spot the drift before it costs you.

Sleep Timing: this athlete's ideal window sits at 22:42 (22:27–22:57), with every night coloured by its Sleep Score.
Sleep Timing 30 nights
Sleep Timing Sleep Duration Wakeup Time +2 more patterns
20:0022:0000:0002:00Jun 27Jul 12Jul 27
Ideal 22:42 Ideal range
Sleep Score<7070–7980–8990–95>95

The science

Built on physiology, not vibes.

Every SAYA metric maps to a mechanism in your autonomic nervous system — and to methods used in sleep research.

  • Evening resting heart rate — how your pre-sleep hour forecasts the night.
  • The HRV-Incline — why a climbing curve after lights-out means recovery debt.
  • Chronotypes — the MCTQ mid-sleep method, measured instead of asked.
Read the science

From the research

“Your heart rate and its variability are a live window into the autonomic nervous system — the system that decides whether tonight is for repair or for vigilance.”

That window is what SAYA reads every evening — explained plainly, sourced properly, on the science page.

Reserve your spot on the waitlist.

SAYA is in private beta with a first group of Garmin athletes. Join now — invites go out in order, the moment the app is ready.

Your invite plus occasional updates. Unsubscribe anytime. Privacy

Not signing up? Tell us what matters anyway.

No email needed — 30 seconds, and it genuinely changes what we build first.

How valuable is each feature to you?
HRV-Incline Detects the stress you carry into sleep from your first hours of HRV.
Not valuable Very valuable
Evening resting HR (eRHR) Your whole evening distilled into one pre-sleep heart-rate number.
Not valuable Very valuable
Correlations Which of your habits actually move your Sleep Score — ranked over weeks.
Not valuable Very valuable
Patterns Your sleep-timing rhythms, each night coloured by its score.
Not valuable Very valuable

Get early access