Ok so my husband thinks it's crazy but I swear by it!
I call it the "Power Shower."
You get in, soak up the nice, warm/hot water for a few minutes. Then switch the water to cold, get a nice rush, and then back to warm/hot. This rejuvenates me completely and I love the way it makes me feel. In high school I always ended with the cold because it closes your pores and I didn't want zits, now I do it because it stimulates all my systems (immune, lymph....) and really gets me going and feeling energized.
But as a warning, tell whoever is in your house at the time what you are doing so that when they hear you scream they will know why! :)
Huge health benefits to Power Showers!
Check this out for the detials!