Heart-rate training · iPhone & Apple Watch
Train by heart rate. Know before you start whether today's session will land.
HealthStars builds your plan from your own VO₂ category, body composition and training history — then scores your readiness against sleep, stress, fuel and the weather you're actually running in. Hard days go where they count.
Requires iPhone. Live heart rate and session control on Apple Watch.
Fitness
Move your VO₂ max, tracked session to session.
Blood pressure
Train toward a systolic target with your clinician's number.
HbA1c
Interval work aimed at a glycemic target you set once.
Weight loss
A rate of change, and the date it gets you there.
Readiness
A score before the session, not a verdict after it.
Every planned workout is scored against what your body brought to it: last night's sleep, stress, nutrition, hydration, medication adherence, the session's own intensity, and the temperature, humidity and altitude you'll be running in. You get one number — and the exact factors holding it down.
Sleep is the largest drag today. Shift the sprint block, or run it at reduced intensity.
What's holding it down
Share of shortfall
Example breakdown from one logged session
The progression
The plan walks you up the zones, in order.
Three modalities, prescribed in weeks. Where you enter depends on your VO₂ category, body-fat range, current training level and lifestyle score — so a conditioned runner skips the base weeks entirely, and a sedentary one doesn't get handed sprints in week one.
MICT
Stage 1 · Zone 2–3 · Continuous
Moderate continuous running that builds the aerobic base your intervals will spend. Prescribed in weeks — zero of them if your base is already there.
HIIT
Stage 2 · Zone 4 · Intervals
Hard efforts with measured recovery between them. Duration and target heart rates come out of your own numbers, not a generic template.
SIT
Stage 3 · Zone 5 · Sprints
All-out sprint intervals, the sharp end of the plan. It opens only once your conditioning — and the day's readiness — supports it.
Live event
Cooldown × HealthStars Max Heart Rate Challenge
A club championship across the Cooldown run club network. Pick the club you represent when you sign up. Your score is the time you hold above 95% of your max heart rate; your best attempt each week counts for your club, and a club's weekly score is the sum of its top scores. Six regular-season weeks decide the eight playoff clubs, then three weeks of head-to-head playoffs crown one national champion.
Weeks 1–6
$250Each playoff club
Clubs earn standings points against their region every week. A club's best five weeks count, and the top two in each region make the playoffs.
Week 7
+$500Each Regional Champion
The two qualifiers in each of the Northwest, Northeast, Southwest and Southeast meet head to head.
Week 8
+$1,000North and South Champions
Northwest meets Northeast, and Southwest meets Southeast.
Week 9
+$4,000National Champion
North against South for the national title: $5,750 in all to the champion club.
Warm up, or it doesn't count
An attempt is scored only once the warm-up is done, you've reached 80% of max HR, and the session comes back compliant. It protects you, and it keeps the board honest.
Ties break on quality
Same time in zone? Tie breaker: lower SIT score, then greater distance in your max zone.
Every runner counts
Your club scores its best results each week, and empty places count as zero, so turning out more runners matters as much as a few fast ones.
Prizes are awarded to clubs from a $10,000 purse
Around the training
The parts that keep you coming back.
Clubs
Train with people
Join a club, take a role, watch the standings move. The weekly window is better with someone else in it.
Goal ETA
A date, not a hope
From your actual rate of change, the app projects when you reach your target — and moves the date when your rate moves.
Referrals
Bring a training partner
Invite someone in and it's tracked to your account, so the people you train with count for something.
Train your heart
Your next run already has a target. Go find it.
Set one goal, log one session, and the plan starts adapting to the athlete you actually are today.
iPhone · Apple Watch