RunIntensity vs Laktic Pace Calculator

Your 40 miles this week hit like 55. RunIntensity is the running app that knows the difference. Distance and pace don't tell you how hard a week really was. A hilly run in the heat or a tempo on tired legs costs more than the mileage suggests. RunIntensity scores every run in Stress-Adjusted Miles (SAM), a five-factor training load model built from heart rate, terrain, surface, cumulative fatigue and conditions. Your weekly mileage becomes a weekly training load you can plan around. TWO NUMBERS, ONE ANSWER EVERY MORNING RunIntensity reads what your watch already writes to Apple Health and scores two things separately, 0–100: • Recovery — heart, nervous system and sleep. HRV, sleep and resting heart rate against your own baseline. Snaps back overnight. • Freshness — muscles, tendons and joints. How much of your recent training your legs have absorbed. Drops with a hard session, climbs back over hours or days. Then one call: Ready, Steady or Recover. Ready only when both are high; Steady when one system is still catching up; Recover when rest is the workout. Recovered isn't the same as healed — this is the app that knows when you're overdoing it. KNOW WHAT TO DO TODAY Your verdict, today's workout, your weekly training load budget and a one-tap start. Widgets, Siri ("What's my readiness?") and Control Center keep it one glance away. FREE FOR EVERY RUNNER • Stress-Adjusted Miles — the real cost of every run • Recovery, Freshness and a daily Ready / Steady / Recover verdict • Weekly SAM budget with mid-week pacing tips • 26-week training load charts • Training planner with periodized phases and race milestones • Personal records and trophies • Shoe mileage tracking • Body soreness tracker — spot patterns before you overdo it • The peer-reviewed research behind every number WORKS WITH ANY WATCH Apple Watch, Garmin, COROS, Polar and more — any run that syncs to Apple Health flows in automatically, duplicates merged. No manual logging. APPLE WATCH APP • Workouts from your wrist with live heart rate, pace and distance • Race Pace interval timer with custom segments and repeats • Complications and Watch widgets with Recovery, Freshness and today's verdict • Live Activity on the Dynamic Island during workouts FRIENDS & THE BOARD — FREE See how your friends are training: readiness, training load, workouts, reactions, weekly leaderboards, head-to-head challenges and streaks. COACH BRADY — YOUR AI RUNNING COACH ($19.99/year, 7-day free trial) An AI running coach that has actually read your training. Every answer is grounded in your readiness, training load and workout history. Coach Brady plans workouts onto your calendar, sends weekly reviews and tracks your goals. Includes the web coach dashboard. COACH MODE — FOR COACHES ($39.99/year) Everything in Coach Brady plus unlimited athletes and groups, side-by-side readiness and load comparisons, assigned plans and push notifications when athletes sync. Coach Brady and Coach Mode require Sign in with Apple and an auto-renewable subscription. PRIVACY FIRST Core calculations happen on your device. RunIntensity reads Apple Health but never writes to it, and syncs only what you choose to share. No ads. No analytics SDKs. No tracking. A training tool, not a medical device. REQUIREMENTS iOS 17.0 or later; watchOS 10.0 or later for the Watch app (optional). Sign in with Apple for Friends, Coach Brady and Coach Mode. SUBSCRIPTION TERMS Coach Brady and Coach Mode are auto-renewable yearly subscriptions charged to your Apple ID at confirmation and renewed automatically unless cancelled at least 24 hours before the end of the period. Manage or cancel in Settings > Apple ID > Subscriptions. Terms of Use (EULA): https://www.apple.com/legal/internet-services/itunes/dev/stdeula/ Privacy Policy: https://www.zerodi.net/runintensity-privacy

Today's threshold paces, adjusted for the heat. Enter a race PR, track or road, and get LT1, Sub-T and LT2 ranges slowed for the temperature and dew point at your track, now or at practice time. Coaches: add your roster, write a note, and share the board as a card. Enter a 5000m, 3200m, 3000m, 1600m, mile or 1500m PR, or a 5 mile, 10K, half marathon or marathon PR, and the app computes the Track and Road Performance training zones: Easy, Long Run, Steady, and the three threshold zones LT1, Sub-T and LT2, with race-pace rows for road distances. Miles or kilometres, your choice. Get today's temperature and dew point for your location, pick a practice time for that hour's forecast, search a city or ZIP, or type the numbers yourself, and every pace is slowed by the heat penalty. The adjustment is scaled by rep length. Short threshold reps with recovery build less heat load than continuous running, so 1–3 minute reps take half the penalty, 4–6 minute reps three-quarters, and 7–10 minute reps and continuous runs the full amount. Within each threshold zone, short reps sit at the fast end of the range, medium reps in the middle, and long reps at the slow end. Every pace shows the per-mile range and the seconds-per-400 m split, so it goes straight to the track. For coaches: keep a roster of athletes on your phone and build a workout board for today's conditions. Pick a zone and rep length and see every athlete's heat-adjusted range, fastest first, filtered by group. Write a note on the board and share it as a card, along with today's paces, the heat, a new PR or a finished session. Log a session: type your reps and see hit, hot or cold against today's band. Export the roster as a file, import one from an assistant coach, or copy a share link that opens the same roster in the web version. How the heat model works: heat score = temperature °F + dew point °F. At 100 or below there is no adjustment. The penalty rises to 10% at 180. Above 180 the app tells you running is not recommended and shows paces at the cap for reference only. Privacy: your location is used only to fetch the weather and the town name. Athlete names and PRs stay on your device unless you export or share them; share cards are drawn by our server from the numbers on screen and are not stored. Sign-in is optional. No tracking, no ads. Training guidance, not medical advice. Use judgment in extreme conditions. Pace engine: Track and Road Performance. Weather data by Open-Meteo.