Support
We're here to help you get the most out of Strength IO.
Have a question, feature request, or found a bug? We'd love to hear from you.
support@strengthio.appFrequently asked questions
How does recovery tracking work?
Strength IO reads up to nine recovery signals from Apple Health — heart-rate variability, Recovery HRV on Apple Watch Series 12 and Ultra 4, sleep, resting heart rate, respiratory rate, blood oxygen, wrist temperature, active calories outside workouts and your resting daytime heart rate — alongside your training history, to estimate how recovered each of your muscle groups is. Recovery and readiness update automatically as new health data becomes available.
Do I need an Apple Watch?
No, an Apple Watch is not required. However, if you have one, Strength IO can access additional health metrics like HRV and provide live heart rate during workouts. The app works great with just iPhone health data too.
Is my data secure?
Yes. Your account, your profile and your workout data are stored on secure, encrypted servers and tied to your Strength IO account, and you sign in with Apple or email. Your workout data includes the heart rate saved with each set you log, and the status you set (sick, injured or on a break). Your profile includes your date of birth, sex, height, weight and body fat; while the Body switch in Sync Options is on, the latest weight, body fat and height in Apple Health update it. Your profile also keeps your phone model, app version and whether an Apple Watch is connected, to help us with support. The rest of your raw HealthKit data — individual heart-rate samples, sleep readings, HRV time-series — is processed on your device and never uploaded. The daily notes Strength IO writes about your readiness and training load are produced on your device. Our analytics and crash-reporting providers receive usage data, your subscription state and the plan you chose under a random account identifier — never your name, your health readings or your payment details, which stay with Apple. Our analytics provider also works out your approximate location (city, region and country) from your internet address. We never sell your data, never use advertising, and never send your data to any third-party AI. See our Privacy Policy for full details.
Does it really use my runs and rides from other apps?
Yes. Any workout that lands in Apple Health — a run in Strava, a ride in Apple Fitness, a class on Peloton — is read by Strength IO and factored into your recovery and readiness. A hard cardio day quietly tones down the next day's lifting intensity. You don't have to log anything in Strength IO for this to work.
How do I set up my equipment?
Tap My plan at the top of Today. The Equipment row lists every station at the gym you train at, and the Gym row lets you add more gyms (like "Home Gym" and "Commercial Gym") with different equipment. At the top of the equipment list you can also choose how bodyweight exercises are treated: the usual mix, only bodyweight (for a place with no equipment), or none at all. When generating workouts, Strength IO will only suggest exercises you can actually perform with your available equipment.
What is the volume target range?
Every muscle group has a minimum number of weekly sets needed to stimulate growth, and a maximum you can do while still recovering. Strength IO tracks your volume and shows whether you're below, within, or above this target range for each muscle group.
What happens to my data if I get a new phone?
Your workout history, PRs, and preferences are tied to your Strength IO account and backed up to our secure servers. Sign in on your new iPhone and everything restores automatically. Your Apple Watch stays in sync with your iPhone during workouts.
How accurate is the 1RM estimation?
Strength IO uses a validated submaximal-load formula to estimate your one-rep max from everyday working sets. It's most accurate for sets of ten reps or fewer and gives you a reliable benchmark without risky maximal attempts.