This actually seems kinda OK. Consent to train is payment for hosting that data. Find another health app/service with more preferable terms if you don't like it. My only beef is if they do an immediate delete without providing a reasonable method for users to export that data first, which is how it reads.
> Find another health app/service with more preferable terms if you don't like it
It never ceases to amaze me how many people defend the Darth Vader style of buying a product: "I am altering the deal; pray I don't alter it any further"
I assume it must be rooted in the just-world fallacy: "Clearly anyone affected must not have been careful enough or did something else wrong. Since I'm careful with my purchases, negative consequences couldn't happen to me."
Related reading: https://blog.codinghorror.com/they-have-to-be-monsters/