Health is a private app for one person. It reads that person's Google Health activity and fitness data when their assistant asks. The only Google permission it requests is activity and fitness, read-only. The readings it can request are daily step totals and exercise session summaries for one to seven completed days.
Health does not request heart rate, location, profile, or any write permission. It has no public sign-up. It does not keep a database of health readings.
The privacy notice explains access, storage, sharing, and deletion. Its single owner operates it.