There is no doubt about this. I think that’s how I dropped to such a low BF% a couple of weeks ago, viz., working in my engine shop day after day, eight plus hours a day, plus driving there and back. Crawling around in a caged race car all the while ratcheting nuts and bolts or stripping wire and pinning connectors is like doing serious fucking yoga. Absolutely exhausting. I bet it put me in serious ketosis.