Some native speakers think this sentence is wrong:
I've exercised for two months.
They say it's wrong because it means I've been exercising 24*7 nonstop for two months.
This reason, however, doesn't convince me completely.
Another similar sentence
I've worked for two months.
doesn't mean I've been working 24*7 nonstop for two months.
So, what's the real problem with it?