Research shows that adventurous men and women have more testosterone (good for libido). You can amp up the intensity of your relationship by amping up the intensity of your activities.

That doesn't mean that you necessarily need to do something really risky, like skydive or punch out a paparazzi. But it does mean that adding a little element of risk to your typical Saturday to-do list will make you - and your relationship - feel a little more alive than usual.

Take a rock-climbing class, or book a white-water rafting trip. Not up for that? Riding a roller coaster will give you a quick shot, as will seeing a scary movie.