- [JSON representation](https://developers.google.com/health/reference/rest/v4beta/AltitudeRollupValue#SCHEMA_REPRESENTATION)

Represents the result of the rollup of the user's altitude.

| JSON representation |
|---|
| ``` { "gainMillimetersSum": string } ``` |

| Fields ||
|---|---|
| `gainMillimetersSum` | `string (https://developers.google.com/discovery/v1/type-format format)` Sum of the altitude gain in millimeters. |