Sexercise! Research reveals how many calories different positions burn - with standing up landing first place at 350 calories and 'lazy' spooning ranking last
http://www.dailymail.co.uk/femail/article-7533699/How-calories-burn-sex-revealed.html
...for zz's benefit, there were no statistics on how many calories ya burn if you are alone when ya have sex.

Liberals are like a "Slinky". Totally useless, but somehow ya can't help but smile when you see one tumble down a flight of stairs!