The precision timer and training analytics platform for lifters who already know how to train. Rest timing, weight tracking, and performance insights — $39.99/year or $79.99 lifetime.
No workout videos. No AI coach. Just data that respects your intelligence.
Get started with a 7-day free trial.
One unified experience that keeps you in the zone. No switching screens, no fumbling between apps—just start your timer, log your set, and keep moving.
Start your rest timer, complete your set, enter weight and reps—all in one place. No mode switching, no friction. The timer lives right where you need it, keeping you in flow throughout your entire session.
Track every rep, every kilogram, every personal record. See your Effective Volume on the dashboard — warm-ups excluded so you see work that counts. Monitor progress across exercises and watch your gains compound over time. All your training data stays on your device.
Training spontaneously? Drop a workout into today's session instantly. Following a structured program? Schedule workouts to specific dates. Intrvl adapts to your training style—plan ahead or go with the flow.
Import complete training programs with multiple workouts. Build multi-week progression blocks, assign sessions to specific dates, and follow structured plans from start to finish. Perfect for serious training cycles.
Optionally backup your programs, schedules, and workout history to iCloud. Seamlessly continue your training across all your devices with automatic synchronisation. Your data, your way, always accessible.
Choose from multiple themes to match your style. Import and edit programs with full control. Customise colours, tweak exercises, and build a training environment that feels right for you.
Tag warm-up sets with one tap. Mark failure sets to track intensity. Intrvl uses these inputs to calculate Strain Score and Effective Volume automatically.
Generate custom programs with ChatGPT, Claude, or any LLM. Our open llms.txt schema lets AI create valid, importable JSON files. Ask your AI to build your perfect program — then import it instantly.
Most apps count Weight × Reps and call it progress. But a 100kg Squat creates far more fatigue than a 100kg Curl. Intrvl measures what your training actually costs — so you can train hard and recover smart.
Warm-up sets excluded automatically. See only the work that counts toward growth — not the sets that just get you ready.
Our proprietary metric weighs exercises by muscle group size and intensity. Legs and back cost more than arms. Failure sets cost more than straight sets. Now you can see the true systemic load.
See where your training focus actually lands. Primary muscles get full credit. Secondary muscles get partial. Spot imbalances before they become problems.
Using the timer isn't just about discipline — it unlocks density analytics. See your volume-per-minute, average rest times, and work capacity trends.
All calculations happen on your device. Your training data never leaves your phone.
Intrvl isn't just for rest periods between sets. Use it for high-intensity training intervals, circuit workouts, sport-specific timers like basketball shot clocks, boxing rounds, Tabata protocols, and more. Whatever your sport or training style, Intrvl keeps you on pace.
Coaches build programs, athletes import them, train with precision tracking, then send performance data back. A complete feedback loop with no servers, no accounts, and no middlemen. Your data, your control.
Coaches create programs using the Program Builder or JSON files. Include workouts, exercises, sets, rest periods, and progression schemes. Distribute via file sharing.
Athletes receive a program file and import it instantly. All workouts, exercises, and progression details load straight into Intrvl. Ready to train in seconds.
Athletes follow the plan, log every set with precision timing, and Intrvl calculates Effective Volume, Strain Score, and muscle distribution automatically. All on-device.
Athletes export their training history as structured JSON and share it with their coach. Coaches review performance in the Analytics dashboard to adjust programming. The loop is complete.
Pick evidence-based rest windows that match your training goals — strength, hypertrophy, or endurance.
Enter weight and reps. Mark warm-ups and failure sets. Intrvl handles the math.
Start the timer, lift, let Intrvl keep rests honest. Every timed rest feeds your density analytics.
Check Effective Volume, Strain Score, and muscle distribution. Train hard. Recover smart. Repeat.
Intrvl isn't for everyone. It's for intermediate and advanced lifters who:
If you're looking for workout videos, AI-generated programs, or gamified challenges — there are plenty of apps for that. Intrvl is the precision tool for people who take training seriously.
Every feature included — Effective Volume, Strain Score, Volume Analytics. No premium tier.
7-day free trial · Then $39.99/yr · Cancel anytime · ~$0.77/week
Pay once · Family Sharing included
Research shows different rest periods drive different training outcomes. Slide to explore the spectrum.
Not all volume is created equal. Research shows compound movements involving large muscle groups create significantly more systemic fatigue than isolation exercises. A set of heavy squats doesn't just fatigue your quads — it taxes your entire nervous system.
Intrvl's Strain Score accounts for this reality. We weight exercises by the muscle groups involved, apply multipliers for failure sets, and exclude warm-ups from fatigue calculations. The result: a single number that tells you how hard your session actually hit your system.
Real athletes using Intrvl to stay on pace, lift heavier, and never miss the next set.
"Love this app. It's exactly what I needed — clean, simple, and the development just keeps getting better. Finally something built for people who actually lift."
"I'm newer to lifting and this helps me remember what I did last time. No more guessing — I just look at my numbers and add weight. That's the whole point, right?"
"Between practice and games, I need to know if I'm recovering enough. The timer keeps me honest and the tracking shows me I'm actually progressing."
Volume Analytics is now a dedicated screen. Persistent session snapshots make every calculation faster. History Export v1.1 ships structured volume data for coach workflows. Plus updated pricing — $39.99/year or $79.99 lifetime.
A volume analytics drill-down, a simplified main menu, and an updated history export that includes volume window comparisons for coaches.
Without data, you can't distinguish between working harder and getting stronger. Here's why guessing about progression keeps you stuck.
Available soon on the App Store. Google Play planned.
Get started with a 7-day free trial.
