Consider what you've asked of it without ever negotiating: the short nights, the skipped meals, the years of sitting in one position, the times you were ill and went in anyway.
It mostly complied. That's what this sentence is pointing at — not a body that looks a certain way, but one that has absorbed a fairly long list of demands and kept operating.
Gratitude toward it rings hollow without some reciprocity, though. Thanks plus continued overdraft is an odd combination.
Give it one thing back today. Water, a walk, an earlier night. A small repayment, actually made.