Dr.ReproEndo said:

Pet owner bonus of training: my dog is also losing weight because we're walking 2-3x more than before.

Exercise transformation with training: went from barely able to walk a block to completing a half marathon last Saturday.

My fitness journey alongside GLP-1 therapy:

• Month 1-2: Walking 15 min/day
• Month 3-4: Walking 30-45 min, started bodyweight exercises
• Month 5-6: Joined a gym, started resistance training
• Month 7+: Running, lifting heavy, cycling for fun

The weight loss made movement possible. The movement made more weight loss possible. Virtuous cycle in action.

The figures, for anyone assembling their own picture. One practical note: write down what you did and when, before you need it. Reconstructing a timeline from memory three months later is how people end up unable to answer the one question that would have resolved it.

LabKate said:

Exercise transformation with training: went from barely able to walk a block to completing a half marathon last Saturday.

Adding the part of the answer the thread has not reached. There is a difference between no evidence and evidence of no effect, and this subject is one where the two get swapped freely in both directions.

Ask again with the specifics and you will get a better answer than this one.

A narrower follow-up, since the general answer is now clear:

How would you tell the difference between that and the alternative explanation?

OP back with an update, since a thread like this is useless without one.

Reporting back for the archive rather than for the thread: I did the narrow version of what was suggested, gave it the full interval, and it settled. Posting it because threads without a follow-up are half a thread.