Your training data
stays yours.

Last updated: July 20, 2026

IntervalSync connects an athlete’s Intervals.icu training account to an AI assistant chosen by the athlete, currently including ChatGPT and Claude, through a private MCP URL. We use Intervals.icu access only to provide the connection and actions that the athlete authorizes.

What we store

We store account metadata, an encrypted Intervals.icu credential, a hash of the private MCP URL token, plan status, and a minimal interaction history containing the MCP tool name, a safe summary, outcome, and time. We do not retain returned training data, raw chat content, plaintext Intervals credentials, plaintext MCP tokens, workout instructions, wellness values, or any response data sent to a connected AI assistant.

How data is used

IntervalSync uses the credential solely to request the Intervals.icu data required by MCP tools an athlete invokes. Depending on the request, those tools can return athlete profile and sport-setting data; completed-activity summaries, intervals, and selected sensor streams; planned workouts; and wellness records. This information is returned to the connected AI-assistant conversation that invoked it; IntervalSync does not retain those returned records. We do not sell training data.

Read and write access policy

Free accounts are read-only and have one Intervals.icu data pull per UTC day. An active Pro subscription has unlimited reads and can use the currently supported, non-destructive, confirmation-gated write tools: create or update a planned workout on the athlete’s Intervals.icu calendar, and update selected wellness fields. The tool request must include an explicit confirmation after the athlete has reviewed the exact change. Every attempted write is recorded in the connection’s activity history without recording the workout instructions or wellness values.

OAuth sign-in asks for read permissions first. A signed-in Pro athlete must deliberately reconnect to grant full Intervals.icu access across activities, wellness, calendar, chats, workout library, and athlete settings. Each Pro permission is requested at the write level, which includes read access. The current MCP tool set does not yet upload completed activity files, modify chats or the workout library, delete Intervals.icu activities or calendar events, or change account settings; broader tools will be disclosed here before they are introduced. No write is made without a tool invocation from a connected AI assistant.

Third parties and billing

Intervals.icu processes the authenticated training requests. ChatGPT processes tool requests and responses under the user’s OpenAI relationship, and Claude processes them under the user’s Anthropic relationship when the athlete chooses Claude. Stripe processes subscription checkout and billing; IntervalSync does not receive card numbers. Use of the Intervals.icu API is also subject to Intervals.icu’s API terms. If a future IntervalSync product surface displays Garmin-sourced activity data, it will provide the applicable Garmin attribution.

Security and deletion

Intervals credentials are encrypted before storage. Athletes can disconnect a training connection or delete their IntervalSync account in Settings. Account deletion removes the IntervalSync account, credentials, private URL hashes, interaction history, sessions, and free-tier usage records. It does not delete, alter, or close the athlete’s Intervals.icu account or its activities. Stripe may retain payment records as required for billing and legal obligations.

Contact

For privacy questions or requests, contact the IntervalSync service operator through the support contact published with the product.