Progress is programmed.
Mainstay is a personalized AI coach that builds a periodized program around your goal, schedule, equipment, and training history, then adjusts it from what you lift and how you recover. $24.99 a month, not $200.
What the coach actually does
Personal coaching built around your long-term goal, adjusted to the week you're actually having. The mechanics: periodized programming that responds to your logged training and daily readiness while keeping the long-term plan intact.
Programming with a spine
Blocks that build and unload on schedule. Prescriptions like 4 × 6-8 at a target RPE, progressed off what you actually lifted. A random generator starts over every day; your training shouldn't.
mesocycles · volume landmarks · RPE · deloads
Readiness that changes the plan
Sleep, HRV, and resting heart rate feed a readiness model each morning. A rough night can pull volume back; solid recovery keeps your planned progression on track. You see why the plan changed, in plain language.
A coach that knows your history
Ask to swap a lift, push a session, or explain a prescription. The coach answers from your actual training history and readiness, not from a script, and tells you why.
your lifts · your logs · your recovery
Progress you can see
Strength curves from your logged sets, PRs when they happen, estimated maxes that move because you moved them. History reads like a training journal kept by someone meticulous.
estimated 1RM trend · PRs · streaks · tonnage
Built for the working set
Keep the next set, target, rest timer, and last performance in view on iPhone. With Apple Watch, log from your wrist and leave the phone in your bag.
Personal-trainer quality coaching, at a fraction of the price.
The kind of programming and attention you'd pay a coach hundreds a month for, at $24.99.
No ads, no selling your data, no "free" tier funded by either. The product costs money because you are the customer, not the inventory.
Asked and answered
Do I need an Apple Watch?
No. An iPhone is all you need, and everything works phone-only. If you have an Apple Watch, Mainstay puts it to good use: your workout opens on your wrist, sets log without touching your phone, and heart rate feeds into your recovery picture. Great with it, complete without it.
Is there an Android version?
Not yet. Mainstay is iPhone-only at launch; that focus is what lets it build deeply around Apple Health and Apple Watch. No Android date is promised.
Do I need a full gym?
No. During setup you tell Mainstay what equipment you have, and it builds your plan and exercise swaps around it. A full gym gives it more options, but it is not required.
What does the beta cost?
Nothing. The price is honest feedback: train normally for two weeks and tell us what worked and what nearly made you quit. Testers who complete the beta get their first year for $149.99 (renews at the public $199.99/yr).
What happens to my health data?
With your permission, Mainstay reads sleep, heart rate, and workout data from Apple Health to coach you, and that is the only thing it is used for. Nothing is sold, nothing is used for advertising, and GPS routes are never uploaded to our servers; they stay in Apple Health under your control. The privacy policy is written in plain English.
Is this medical advice?
No. Mainstay is AI coaching software, not a doctor or a certified trainer, and its recommendations can contain errors. Talk to a physician before starting a new program, and read the safety and limitations page before you train.
Can I quit the beta or delete my data?
Anytime, no questions. Delete your account from inside the app and your server-side data is permanently removed. The beta involves no payment, so there is nothing to cancel.
Who is behind this?
One founder who lifts, plus the coach he wanted to exist. Applications, invites, and support all come from the same person. Operated by ALC SFR LLC, d/b/a Mainstay.
Apply for the beta
Looking for experienced lifters: 2+ years training, 3+ sessions a week, iPhone required, Apple Watch a plus.
If that is not you yet, apply anyway and you will go on the list for later waves.
Before applying, read the Terms of Service, Privacy Policy, and Beta Program Agreement.