Asked by: Daisy Joy, Brecon
A 2017 study at Loughborough University did indeed find that a hot bath increases your metabolic rate slightly. As your core temperature rises, your heart has to pump harder to send warm blood to your skin in an attempt to stay cool, and your body also uses energy manufacturing special ‘heat-shock’ proteins that try to reduce damage
to your cells from the higher temperatures.
It’s a pretty slow way to shed the pounds, though. An hour in a hot bath burns an extra 61kcal compared with just sitting down. That’s less than the calories in one digestive biscuit. If you spend that hour doing anything remotely active, you’ll burn more calories. Go for a walk, and you’ll burn the same amount in 15 minutes.