It changes how confident today's suggestion is, and on a clearly low day it can suggest a lighter weight, never a heavier one; your logged sets set the weight.
Here is the whole rule. Your logged sets set the weight. On a day your signals read clearly low, Rhythm can suggest a lighter one, never a heavier one, and the number you lift is always yours to type. A symptom you log can ease a session too. Your cycle phase gives context and never sets a weight. If you would rather your wearable did not shape the suggestion, turn off “Fold wearable recovery data into Smart Targets” in Settings.
A recovery reading is a measurement of one night, not a verdict on a person — and a wrong verdict is not harmless. Being told your sleep was poor can make the session worse even when the sleep was fine. So Rhythm uses those signals to say how sure it is. When they read clearly low it can offer a lighter weight, never a heavier one, and the number on the bar stays tied to the thing it can actually see: what you lifted last time.
Every read in the app opens. Tap the day's suggestion and you get the reasons behind it in plain words. Tap the confidence line and you get what fed it. Tap the “adjusted today” pill on an exercise and you get what changed and why. There is no number in Rhythm you cannot open.
When the data is thin, Rhythm says so rather than filling the gap. A low reading is not a diagnosis, and nothing the app tells you about your recovery is medical advice. And when it suggests an easier day, it names something you can still do — the door stays open.