# Strength IO: Workout Tracker — Intelligent strength training > Adaptive strength training that personalizes workouts based on real-time recovery and activity data. (iPhone/iPad app by Crimson IO LLC.) - Source: https://appshunter.io/ios/app/strength-io-workout-tracker/id6776702706 (this page in markdown: same URL + `.md`) - Developer: [Crimson IO LLC](https://appshunter.io/developer/1864406504) - Category: Health & Fitness - Price: Free with in-app purchases - Rating: 5.00/5 from 1 App Store ratings - Age rating: 4+ - Requires: iOS 26.4 · 32 MB - Languages: American English - Released: 2026-07-12 - Data updated: 2026-08-16 - Monetization: freemium - User reviews in markdown: https://appshunter.io/ios/app/strength-io-workout-tracker/id6776702706/reviews.md ## What is Strength IO? Everything in. Your session out. Strength IO reads everything you do — your lifts, the runs, rides, and games you log in other apps, and your recovery signals from Apple Health — and builds the strength session your body can handle today. Heavier when you're fresh. Lighter when you're not. It doesn't just count your sets. It computes. WHAT IT DOES • Adaptive training — Every weight is anchored to your real effort and per-muscle recovery, set by set. Fresh muscles get pushed; taxed ones get volume pulled back, never forced. • Your whole week counts — Logged a long run in Strava, a ride on Peloton, a game in Apple Fitness? Strength IO reads it through Apple Health and adjusts today's lifting. No double-logging. • Readiness from seven signals — HRV, sleep, resting heart rate, respiratory rate, blood oxygen, wrist temperature, and heart-rate recovery combine into one daily readiness estimate — not a single number from a single source. • Training load — Your last 7 days are weighed against your last 28, so you can see at a glance whether you're ramping up too fast, holding steady, or backing off. One plain-language read — from well below to well above your usual — over a simple recent-vs-baseline chart. Build instead of break down. • Smart volume — Each muscle's weekly volume is kept inside its effective range: enough to grow, never junk sets. • Athlete Profile — The whole athlete in one place. A Strength Score for every muscle you train, rolled up by push, pull, and legs and scored from your own best lifts — so a cable row counts as much as a barbell. On the cardio side: your VO₂max against age- and sex-based norms, resting heart rate and heart-rate recovery alongside, and an efficiency trend for whether the same pace is costing your heart less. It's all tracked over time, so a plateau reads as a flat line and progress as a rising one. • Private by default — The coaching runs on your device. Your data stays yours. BUILT FOR The multi-sport lifter. If you train 3–4 times a week, wear an Apple Watch, and also run, ride, or play — Strength IO reads all of it. STRENGTH IO PRO Strength IO starts with a free trial — the full app, nothing held back. After the trial, a monthly or yearly subscription keeps everything unlocked. Subscriptions renew automatically unless cancelled at least 24 hours before the end of the period. Manage or cancel anytime in your App Store account settings. Terms: https://strengthio.app/terms Privacy: https://strengthio.app/privacy iPhone & Apple Watch. Estimates based on your data. Not medical advice. https://www.apple.com/legal/internet-services/itunes/dev/stdeula/ https://strengthio.app/privacy ## Key features - Adaptive training based on per-muscle recovery - Integrates with Apple Health for activity logging - Readiness score from seven health signals - Training load analysis (7-day vs. 28-day) - Smart weekly volume tracking - Comprehensive athlete profile with strength and cardio scores - Private by default, on-device coaching ## Pricing and in-app purchases Base price: Free. **Subscriptions** | Subscription | Price | Period | | --- | --- | --- | | Strength IO Pro | $9.99 | per month | | Strength IO Pro | $59.99 | per year | ## Frequently asked questions about Strength IO ### What is Strength IO? Strength IO is an intelligent strength training app that personalizes your workouts based on your body's recovery signals and logged activities from other apps. It aims to help you train smarter by adjusting intensity and volume to prevent overtraining and optimize muscle growth. ### How does Strength IO determine workout intensity? Strength IO uses seven key health signals, including HRV, sleep, resting heart rate, and more, to estimate your daily readiness. It then anchors your workout weights to your real effort and per-muscle recovery, making sessions heavier when you're fresh and lighter when you're not. ### Does Strength IO work with other fitness apps? Yes, Strength IO integrates with Apple Health to read your logged activities from other apps like Strava, Peloton, and Apple Fitness. This allows it to adjust your lifting sessions without requiring you to double-log your workouts. ### What kind of data does Strength IO track for athlete profiles? Strength IO builds a comprehensive athlete profile that includes a Strength Score for every muscle group, rolled up by push, pull, and legs. It also tracks VO₂max, resting heart rate, heart-rate recovery, and cardio efficiency trends over time. ### Is Strength IO private? Yes, Strength IO is private by default. The coaching and analysis run on your device, ensuring that your personal data stays with you. ### What are the subscription options for Strength IO Pro? Strength IO offers a free trial of the full app. After the trial, you can choose a monthly subscription for $9.99 or a yearly subscription for $59.99 to keep all features unlocked. Both plans include a 7-day free trial. ### How do I cancel my Strength IO Pro subscription? Subscriptions renew automatically unless cancelled at least 24 hours before the end of the current period. You can manage or cancel your subscription anytime through your App Store account settings. ### What devices is Strength IO available on? Strength IO is available for iPhone and Apple Watch, providing a seamless experience for tracking your workouts and recovery. ## Version history (last 5 releases) ### 1.08 — 2026-08-11 Introducing Siri Intents. Just ask Siri to start a Strength IO workout and you ready to go ### 1.07 — 2026-08-11 Bug fixes ### 1.06 — 2026-08-07 Bug fixes ### 1.03 — 2026-07-22 Bug fixes ### 1.02 — 2026-07-19 Bug Fixes ## More apps by Crimson IO LLC - [Portional](https://appshunter.io/ios/app/portional/id6757086849) - [Dayrift: Countdown Timer](https://appshunter.io/ios/app/dayrift-countdown-timer/id6757203118) - [Bedhead: Sleep Tracker](https://appshunter.io/ios/app/bedhead-sleep-tracker/id6758223469) - [Fit Guild](https://appshunter.io/ios/app/fit-guild/id6761586456) - [Snack: Calorie & Macro Tracker](https://appshunter.io/ios/app/snack-calorie-and-macro-tracker/id6788543910) All apps by Crimson IO LLC: https://appshunter.io/developer/1864406504 --- *Data collected daily from the US App Store and indexed by [AppsHunter](https://appshunter.io/). User reviews are verbatim App Store reviews. Ratings, prices and chart positions refresh continuously; this snapshot is from 2026-08-16.*