Can you get the benefits of exercise from sitting in your hot tub? Researchers from Loughborough University studied 12 men (we know, we know) in an experiment to compare the benefits of having a long, hot bath versus an hour of cycling.
While technically one can burn significantly more calories (average 630) during a one hour cycle, there was also a decent energy expenditure while sitting in hot water (average of 140 calories). In essence, sitting in a hot bath resulted in the same caloric burn as seen during a short, brisk walk.
For more details on the story, check out http://www.startribune.com/the-hot-tub-diet-soaking-can-burn-as-many-calories-as-mild-exercise/418525993/