Mainstay Safety and Limitations

Mainstay is an AI fitness coach. It plans training, tracks workouts, and adapts to your recovery data. It is a tool for generally healthy adults who train, and it has real limits. Please read this page before you rely on it.

Who Mainstay is not for

You must be 18 or older to use Mainstay. It is only for adults.

Do not use Mainstay for your training if any of the following applies, unless a physician has reviewed your situation and cleared you to train (beta testers: the Beta Program Agreement excludes these situations entirely, even with clearance):

You are recovering from an active injury or in rehabilitation. Mainstay plans training for healthy movement. It is not a rehab program and cannot supervise one.
You are pregnant. Training during pregnancy should be planned with your physician, not with this app.
You have a significant medical condition, including but not limited to heart disease, high blood pressure, respiratory conditions, diabetes, or any condition your physician monitors, and you have not received physician signoff to follow a self-directed exercise program.

If in doubt, ask your physician first. Bring them your planned training if it helps the conversation.

What the AI can and cannot do

Mainstay's coaching is generated by an AI using the training history, recovery data, and goals you provide. That means:

It cannot see you. It has no camera and no eyes on your form. It cannot tell whether your squat is safe, your back is rounding, or a weight is too heavy for you today. Form is your responsibility, and a qualified in-person coach is the right tool for learning it.
It can make mistakes. AI-generated plans and answers can be wrong, generic, or a poor fit for your situation. Treat every recommendation as a suggestion to evaluate, not an instruction to obey.
It only knows what you tell it and what your device measures. If your data is incomplete or wrong, the plan will be too.
It is fitness guidance, not medical advice. Nothing in Mainstay is a diagnosis, treatment, or a promise of results.
People check its work, but not in real time. The Mainstay team reviews coach conversations and generated workouts to find and fix mistakes (see the Privacy Policy). That review happens after the fact. Nobody is watching your workout as it happens, so the decision to do or skip an exercise is always yours.

Stop if it hurts

Pain is information. During any workout:

Stop the exercise immediately if you feel sharp pain, joint pain, chest pain, dizziness, unusual shortness of breath, or anything that feels wrong.
Do not train through pain because the plan says there are sets left. Skip or swap the exercise in the app; the plan adapts.
If a movement hurts every time you do it, stop programming it and talk to a physician or physical therapist.

Emergencies

Mainstay cannot detect or respond to a medical emergency. If you experience chest pain, fainting, a suspected serious injury, or any other emergency, stop and call your local emergency services (911 in the United States) immediately. Do not use the app or the coach chat to seek help in an emergency.

Questions

Questions about this page: support@mainstay.fit. See also our Terms of Service, including the assumption of risk and release in Section 4, our Privacy Policy, and our Support page.