Body Battery
Recovery & Readiness0–100
Target80–100 after a full night's sleep
A fuel-tank reading for your body — how much energy you have left right now.
Target80–100 after a full night's sleep
Coach Icarus Reference
What every number actually means
Plain language for every metric we track — what it is, why it matters, and what a good number looks like. No jargon, no PhD required.
42metricsUpdated for 2026 season
Recovery & Readiness
4How recovered your body is and whether you're ready to train hard.
HRV Status
Recovery & Readiness
TargetBalanced
A three-level signal — Balanced, Unbalanced, or Low — describing the overall trend of your heart rate variability.
TargetBalanced
Training Readiness
Recovery & Readiness0–100
Target70–100 for hard sessions
A composite score that answers the question: 'Am I ready to train hard today?'
Target70–100 for hard sessions
Net Energy (Body Battery)
Recovery & Readinesspoints
TargetNeutral to positive most days
The difference between how much your Body Battery charged and how much it drained over 24 hours.
TargetNeutral to positive most days
Heart & Cardiovascular
6Heart health, cardiovascular stress, and aerobic fitness markers.
Heart Rate Variability (HRV)
Heart & Cardiovascularms (milliseconds)
TargetHighly personal — focus on your own trend, not someone else's number
The tiny variation in time between each heartbeat — and a powerful window into your nervous system's recovery state.
TargetHighly personal — focus on your own trend, not someone else's number
Resting Heart Rate (RHR)
Heart & Cardiovascularbpm (beats per minute)
TargetTypically 40–60 bpm for active adults; lower is generally better
How many times your heart beats per minute when you're completely at rest — a classic marker of cardiovascular fitness.
TargetTypically 40–60 bpm for active adults; lower is generally better
Stress Score
Heart & Cardiovascular0–100
TargetBelow 50 for most of the day; high scores during workouts are expected
A measure of physiological stress — how much your nervous system is working at any given moment.
TargetBelow 50 for most of the day; high scores during workouts are expected
VO2 Max
Heart & Cardiovascularml/kg/min
Target45–55 ml/kg/min is solid for recreational runners; 55+ is competitive; elite runners often exceed 70
Your aerobic engine size — the maximum rate at which your body can use oxygen during exercise.
Target45–55 ml/kg/min is solid for recreational runners; 55+ is competitive; elite runners often exceed 70
Fitness Age
Heart & Cardiovascularyears
TargetBelow your chronological age is the goal
The age that your VO2 Max corresponds to, according to population research — your biological fitness clock.
TargetBelow your chronological age is the goal
Heart Rate Zones (Zone 1–5)
Heart & Cardiovascularbpm
TargetMost easy runs should stay in Zone 1–2
Five intensity buckets based on heart rate — from easy recovery to all-out effort.
TargetMost easy runs should stay in Zone 1–2
Sleep
6Quality, duration, and what actually happened during the night.
Sleep Score
Sleep0–100
Target80+ is the target; consistent 90+ is elite recovery
A single number summarizing how restorative last night's sleep actually was.
Target80+ is the target; consistent 90+ is elite recovery
Sleep Duration
Sleephours
Target7–9 hours for most adults; 8–10 for athletes in heavy training
Total time spent asleep — not just time in bed.
Target7–9 hours for most adults; 8–10 for athletes in heavy training
Sleep Efficiency
Sleeppercentage (%)
Target85% or higher
The percentage of time you spent in bed that you were actually asleep — not tossing, turning, or awake.
Target85% or higher
Deep Sleep
Sleeppercentage of total sleep (%)
Target13–23% of total sleep (roughly 60–90 minutes per night)
The deepest, most physically restorative phase of sleep — when your body does its real repair work.
Target13–23% of total sleep (roughly 60–90 minutes per night)
REM Sleep
Sleeppercentage of total sleep (%)
Target20–25% of total sleep (roughly 90–120 minutes per night)
The dream stage of sleep — where your brain processes emotions, stress, and skills learned during the day.
Target20–25% of total sleep (roughly 90–120 minutes per night)
Light Sleep
Sleeppercentage of total sleep (%)
Target50–60% of total sleep is typical
The transitional sleep phase — important but less restorative than deep or REM.
Target50–60% of total sleep is typical
Training Load & Fitness
5How much training stress you've accumulated and how fitness is trending.
Training Load (TRIMP)
Training Load & Fitnessarbitrary units (AU)
TargetVaries by individual; the trend over time matters more than the absolute value
A measure of how much stress a single workout placed on your body, combining duration and intensity.
TargetVaries by individual; the trend over time matters more than the absolute value
CTL — Chronic Training Load (Fitness)
Training Load & Fitnessarbitrary units (AU)
TargetGrowing slowly, 5–8 points per week is a healthy build rate
Your long-term fitness baseline — built slowly over months of consistent training.
TargetGrowing slowly, 5–8 points per week is a healthy build rate
ATL — Acute Training Load (Fatigue)
Training Load & Fitnessarbitrary units (AU)
TargetSlightly above CTL during training blocks; drops during taper
Your short-term fatigue — how tired you've made yourself in the past 7 days.
TargetSlightly above CTL during training blocks; drops during taper
TSB — Training Stress Balance (Form)
Training Load & Fitnessarbitrary units (AU)
Target+5 to +25 for race day; training typically keeps you between –10 and –30
The gap between fitness and fatigue — your 'form' or readiness to race.
Target+5 to +25 for race day; training typically keeps you between –10 and –30
Load Balance (A:C Ratio)
Training Load & Fitnessratio
Target0.8 to 1.3 — the sweet spot
The ratio of acute (7-day) to chronic (28-day) training load — your injury risk indicator.
Target0.8 to 1.3 — the sweet spot
Activity & Performance
9Per-workout numbers describing how your run, ride, or session went.
Pace
Activity & Performancemin/km or min/mile
TargetHighly personal; focus on your own trend over time
How long it takes you to cover one kilometer or one mile — your speed in runner's language.
TargetHighly personal; focus on your own trend over time
Average Heart Rate
Activity & Performancebpm
TargetDepends on target zone; easy runs should average Zone 1–2
Your average heart rate across the entire workout.
TargetDepends on target zone; easy runs should average Zone 1–2
Cadence
Activity & Performancespm (steps per minute)
Target170–180+ spm is the commonly cited 'ideal' range
How many steps you take per minute — your running turnover rate.
Target170–180+ spm is the commonly cited 'ideal' range
Elevation Gain
Activity & Performancemeters or feet
TargetDepends on the goal; flat race prep vs. mountain trail are very different
Total vertical meters climbed during a workout.
TargetDepends on the goal; flat race prep vs. mountain trail are very different
Duration
Activity & Performanceminutes or hours
TargetMatches your training plan targets for each session
How long the workout lasted.
TargetMatches your training plan targets for each session
Distance
Activity & Performancekm or miles
TargetFollows your training plan's weekly target
Total ground covered during the activity.
TargetFollows your training plan's weekly target
RPE — Rate of Perceived Exertion
Activity & Performance1–10 scale
TargetEasy days: RPE 3–4; moderate sessions: 5–6; hard sessions: 7–8; races: 9–10
How hard a workout felt — rated by you, on a scale from 1 (barely moving) to 10 (everything you had).
TargetEasy days: RPE 3–4; moderate sessions: 5–6; hard sessions: 7–8; races: 9–10
Lap Splits
Activity & Performancepace or time per lap
TargetEven or slightly negative splits for most race distances
A breakdown of each segment of your workout — showing how your pace or effort varied.
TargetEven or slightly negative splits for most race distances
Power
Activity & Performancewatts (W)
TargetHighly individual; compare to your own FTP (Functional Threshold Power)
The rate at which you're doing mechanical work — a more precise measure of effort than heart rate or pace alone.
TargetHighly individual; compare to your own FTP (Functional Threshold Power)
Daily Activity
4Baseline movement and lifestyle metrics captured throughout your day.
Steps
Daily Activitysteps/day
Target7,000–10,000 steps/day is a commonly cited healthy target
Total number of steps taken throughout the day — your non-exercise movement baseline.
Target7,000–10,000 steps/day is a commonly cited healthy target
Floors Climbed
Daily Activityfloors
Target10+ floors/day
How many flights of stairs your Garmin detected you climbing.
Target10+ floors/day
Calories
Daily Activitykcal
TargetActive calories vary by training phase; focus on fueling appropriately to match expenditure
Total energy your body burned — split between resting metabolism and active movement.
TargetActive calories vary by training phase; focus on fueling appropriately to match expenditure
Active Time
Daily Activityminutes
Target30+ minutes most days
Minutes spent in moderate-to-vigorous movement throughout the day.
Target30+ minutes most days
AI Coaching Analysis
8Coach Icarus's composite scores that combine many signals into one picture.
Run Score
AI Coaching Analysis0–100
Target75+ is well-executed; 85+ is excellent
Coach Icarus's overall grade for a single workout — combining pacing, heart rate zones, and effort quality.
Target75+ is well-executed; 85+ is excellent
Aerobic Efficiency
AI Coaching Analysispercentage
Target80%+ means strong zone adherence
How well you stayed in your target heart rate zones — a measure of pacing discipline.
Target80%+ means strong zone adherence
Pacing Stability
AI Coaching Analysispercentage
Target85%+ for steady efforts; varies for interval sessions
How consistent your pace was throughout the run — were you steady or all over the place?
Target85%+ for steady efforts; varies for interval sessions
Effort vs. Plan
AI Coaching Analysisqualitative
TargetSpot On or Close for most sessions
How your actual effort compared to what your training plan called for — Spot On, Close, Drifted, or Missed.
TargetSpot On or Close for most sessions
Biomechanics Score
AI Coaching Analysispercentage
Target75%+ is good; 90%+ is excellent
Coach Icarus's AI assessment of your running mechanics — cadence, form consistency, and efficiency of movement.
Target75%+ is good; 90%+ is excellent
Physiology Score
AI Coaching Analysispercentage
Target75%+ indicates a physiologically clean effort
An AI assessment of how your heart rate, perceived effort, and cardiovascular response matched expectations for the session.
Target75%+ indicates a physiologically clean effort
Recovery Needed
AI Coaching Analysisqualitative: Low / Moderate / High
TargetVaries; high-intensity sessions naturally require more recovery than easy days
How much recovery time Coach Icarus estimates you'll need after a workout before you're ready to train hard again.
TargetVaries; high-intensity sessions naturally require more recovery than easy days
Time in Target Zone
AI Coaching Analysisminutes or percentage
Target80%+ in target zone for zone-specific sessions
How many minutes (and what percentage) of your run was spent in the heart rate zone your plan called for.
Target80%+ in target zone for zone-specific sessions