Threshold vs Stellar Intervals

The Norwegian running method, adapted to your life. Threshold builds a complete, periodized running plan around your goal, current fitness, training history, and weekly schedule. It applies the principles behind Norwegian threshold training while scaling the dose to your level. This is a connected training plan rather than the same week repeated. Your training moves through base, build, peak, taper, and transition phases, with progressive volume and recovery weeks built in. HOW IT WORKS Tell Threshold about your running background, race goal, available days, and current training. The app creates a multi-week plan with clear warm-ups, intervals, target paces, recoveries, and coaching notes. WHAT YOU GET Adaptive Training Plan Your next sessions and weeks respond to what you actually complete, the effort you report, schedule changes, and missed training. Norwegian Threshold Sessions Controlled threshold work inspired by the Norwegian Method, including double-threshold days when they fit your experience, volume, and recovery capacity. Precise Training Paces Training zones and targets use your race results and current fitness so every easy run, threshold session, and interval workout has a clear purpose. Progressive Training Weeks Volume and intensity develop across real phases. Recovery weeks and guardrails help keep changes measured when your training load increases. Log, Edit, and Adjust Record completed sessions, correct the details later, skip or move a workout, and continue into the next block without losing your history. Coach Chat Ask questions about the plan, report fatigue, and get answers grounded in your completed training and current week. Apple Health Import Connect Apple Health to import completed runs and relevant workout details into your training history. WHO IT IS FOR - Runners preparing for a 5K, 10K, half marathon, marathon, or longer race - Runners who want a structured plan without hiring a full-time coach - Experienced athletes who want to apply Norwegian threshold principles with a practical weekly schedule - Developing runners who need the method scaled to their current training ABOUT THE METHOD Norwegian threshold training centers on accumulating high-quality work near threshold while keeping intensity controlled enough to recover and repeat. Threshold turns those principles into a plan you can understand, complete, and adjust week by week. Threshold provides training guidance and is not medical advice. Privacy Policy: https://thethresholdapp.com/privacy Terms of Use: https://thethresholdapp.com/terms Support: https://thethresholdapp.com/support

Most Norwegian 4x4 timers count the clock. Stellar Intervals counts what matters: the time your heart is truly in the zone — and how fast it recovers afterward. THE PROBLEM WITH CLOCK-BASED 4x4 The Norwegian 4x4 protocol calls for four 4-minute intervals above ~85% of your max heart rate. But it takes time to climb into that zone — often 60 to 90 seconds. A standard timer counts that ramp-up as "work," so you get an uneven, watered-down dose every session. Two workouts that look identical on the clock can be completely different efforts. TRUE TIME IN ZONE Stellar Intervals fixes this with a heart-rate-gated timer. The interval clock starts only when you cross your 85% threshold — and pauses the instant you drop below it. No more junk time. Every session delivers a true 16 minutes of high-intensity stimulus. Repeatable, predictable, honest. A CLEAN SIGNAL: HEART-RATE RECOVERY Here's what true time in zone unlocks. Heart-rate recovery (HRR) — how many beats per minute your heart drops in the first minute after an interval — is one of the most studied markers of cardiovascular fitness. But it's only meaningful if the effort before it was consistent. Because Stellar Intervals standardizes every interval to the same load, your HRR becomes a clean, comparable number you can trust. Track it interval to interval and week to week, and watch your fitness improve in a metric measured from your own training. THE SCIENCE The Norwegian 4x4 protocol is the gold-standard interval method for improving VO2 max — and VO2 max is one of the strongest predictors of long-term health and longevity. Stellar Intervals helps you execute the protocol precisely and follow your progress through HRR, a marker researchers have long tied to heart health and aerobic fitness. FEATURES Heart-rate-gated timer — counts only true time in zone Auto-pause when you fall below 85% HRmax Per-interval heart-rate recovery (HRR) tracking Long-term HRR and time-in-zone trends Works with Apple Watch and Bluetooth chest straps Sport-agnostic: run, bike, row, ski, or elliptical Apple Health integration Clean, distraction-free workout screen HONEST BY DESIGN Stellar Intervals does not estimate or claim to measure your VO2 max — no app can do that accurately from your wrist. What we do measure, we measure for real: your true time in zone and your heart-rate recovery. Two numbers you can trust, both improving as you train. WHO IT'S FOR Runners, cyclists, and rowers chasing VO2 max gains. Longevity-minded people who already track HRV, sleep, and biomarkers. Anyone who wants their 4x4 done with precision instead of guesswork. Requires a heart rate source (Apple Watch, Apple Airpods Pro 3 or Bluetooth HR monitor). Start your first true interval today.