A recent study has shown that afternoon baths just twice a week produce a moderate but persistent lift to mood apparently similar to the affect of physical exercise. That doesn't mean you can ignore the exercise but perhaps fit in a couple of baths too.
This has long been one of my recommendations working with clients with depression and other mood disorders. It works but I'd assumed it was more to do with the calming and sensory effects of the hot water, quiet time and perhaps a spot of lavender oil. However the study (reported by Clare Wilson in October's edition of the New Scientist) suggested that this method could work because it raises body temperature in the afternoon and therefore helps to restore the normal circadian rhythm of temperature, which is often disturbed in people with depression. We are coming to realise more how our circadian rhythms affects our mental and physical wellbeing. Watch out for some more findings on this subject matter very soon!