One-time purchase · No subscriptions

Time Every Interval. Track Every Lift. Know What Works.

The precision timer and training analytics platform for lifters who already know how to train. Rest timing, weight tracking, and performance insights — without the subscription.

No workout videos. No AI coach. Just data that respects your intelligence.

1-5+
Minutes Precision
100%
Offline Ready
Workouts

Get started with a 14-day free trial.

Dashboard 1D 7D 1M 3M 4 SESSIONS 12k VOLUME # 28 SETS STRAIN SCORE 14.5 Recovery EFFECTIVE VOLUME 8.4k kg Weights 0/15 Pull Day A Complete Example Program 🗓️ Mon, 29 Dec TODAY'S TRAINING 0kg Effective • 0 Hard Sets Heaviest Set Sets Completed 0 Difficulty Moderate Ready to start... 03:00 Rest Timer Workout QUICK PRESETS CLASSIC 20/10 BEGINNER 30/15 ADVANCED 40/20 WORK TIME 20 SEC + 5s 2m REST TIME 10 SEC + 5s 2m ROUNDS 8 4 20 START WORKOUT Sports 🏀 Basketball 4 timers 🏉 Rugby 3 timers ⚽️ Soccer 3 timers 🏈 Football 4 timers 🏒 Hockey 🤽‍♂️ Polo
Business Model
No Monthly Fees
Privacy
100% On-Device*
*iCloud sync via Apple. We never see your data.
Live Activity
Lock Screen Timer
Log Sets
One-Tap Entry
Intervals
Fully Custom
Alerts
Sound & Flash
Sports
Shot Clocks
Match Timer
Period Tracking

Built for How You Actually Train

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.

Unified Timer & Logging

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.

Full Weight Tracking

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.

Quick Start or Schedule

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.

Multi-Workout Programs

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.

iCloud Sync

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.

Make It Yours

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.

Mark What Matters

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.

AI-Friendly Integration

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.

Beyond Volume. Beyond Guesswork.

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.

Effective Volume

Warm-up sets excluded automatically. See only the work that counts toward growth — not the sets that just get you ready.

Strain Score

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.

Muscle Heatmap

See where your training focus actually lands. Primary muscles get full credit. Secondary muscles get partial. Spot imbalances before they become problems.

Training Density

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.

One Timer.
Endless Workouts.

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.

Rest Between Sets
HIIT Intervals
Shot Clocks
Circuit Training
Boxing Rounds
Tabata
Endurance Blocks
Custom Protocols
3:00
Strength Rest
0:30
HIIT Work
24:00
Shot Clock
3:00
Boxing Round

The Complete Coach-Athlete Loop

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.

1. Build Programs

Coaches create programs using the Program Builder or JSON files. Include workouts, exercises, sets, rest periods, and progression schemes. Distribute via file sharing.

2. Athletes Import

Athletes receive a program file and import it instantly. All workouts, exercises, and progression details load straight into Intrvl. Ready to train in seconds.

3. Train & Track

Athletes follow the plan, log every set with precision timing, and Intrvl calculates Effective Volume, Strain Score, and muscle distribution automatically. All on-device.

4. Send Data Back

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.

How it works

Set your rest targets

Pick evidence-based rest windows that match your training goals — strength, hypertrophy, or endurance.

Log and classify

Enter weight and reps. Mark warm-ups and failure sets. Intrvl handles the math.

Time your rest

Start the timer, lift, let Intrvl keep rests honest. Every timed rest feeds your density analytics.

Review and progress

Check Effective Volume, Strain Score, and muscle distribution. Train hard. Recover smart. Repeat.

Built for Lifters Who Know What They're Doing

Intrvl isn't for everyone. It's for intermediate and advanced lifters who:

  • Already know how to perform their exercises
  • Follow structured programs (or build their own)
  • Understand that rest periods are a training variable
  • Want data, not hand-holding
  • Are tired of subscriptions for basic tracking

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.

One Purchase. Forever Yours. All Analytics Included.

No premium tier for "advanced" features. No monthly fee for your own data. Every feature — including full training analytics — is included in one payment.

One-Time Payment
$
24.99

14-day free trial · Then pay once, own it forever · $24.99 USD

  • Unlimited workouts and programs
  • Full weight and progress tracking
  • Strain Score and Effective Volume analytics
  • Muscle strain distribution tracking
  • Multi-use interval timers
  • iCloud sync and backup
  • Import and edit programs
  • Multiple themes and customisation
  • Works completely offline
  • No ads, ever
Start Your Free Trial

Rest Period = Training Variable

Research shows different rest periods drive different training outcomes. Slide to explore the spectrum.

30s 5min+
2:00
Rest Period
📈 Hypertrophy
🔥 Endurance
30–90 seconds

High metabolic stress. Builds work capacity, lactate tolerance, and conditioning.

📈 Hypertrophy
1–3 minutes

Balanced recovery. Maintains volume across sets to maximize muscle growth stimulus.

💪 Strength
3–5+ minutes

Full recovery. Every rep performed at maximum force output with optimal technique.

💡 Intrvl lets you set precise rest periods for each exercise, automatically adapting to your training goals. No guesswork—just science-backed recovery.

Beyond Rest: The Strain Equation

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.

What lifters say

Real athletes using Intrvl to stay on pace, lift heavier, and never miss the next set.

BH
Brendon H.
Lifter

"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."

BO
Britta O.
New lifter

"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?"

MJ
Marcus J.
College athlete

"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."

From the blog

Intrvl app icon with version 2.7 in neon blue and pink gradient
Product 6 min read

Intrvl 2.7: Coach Data, Program Builder & New Analytics

Share training data with your coach. Build programs on the web. Import and export custom exercises. Plus a new analytics dashboard, muscle group filters, and timer fixes.

Get started on mobile

Available soon on the App Store. Google Play planned.

📱 App Store

Get started with a 14-day free trial.