If a relaxing soak in the tub sounds like the perfect way to cap off a rough day, you’re right – as long as you don’t overdo it. Go ahead and dim the lights, grab a glass of wine and play some light music, but keep an eye on the clock. According to a new study, the optimum length of time to spend in the bath is just 22 minutes. Anything longer than that could actually leave you feeling dehydrated. In fact, many health professionals recommend getting out of the tub before 30 minutes.