I just don't think that Brooke could've done this. Exercise gives you endorphins. Endorphins make you happy. Happy people just don't shoot their husbands, they just don't.
The first time I ever heard the word Endorphins being used was believe it or not in Legally Blonde, the Hollywood flick with Reese Witherspoon as the airhead blonde and since that time it keeps popping up in magazines, journals and even in the bible, Cosmo.. So here goes as far as I know what that smart word means..
 What are Endorphins ?
A big part of our natural defenses against pain depends on physical activity and rest. Exercise stimulates the release of natural painkillers, called endorphins, improves circulation, limbers up your muscles and helps you sleep. Rest and sleep allow your body to heal from the traumas of the day and are vital for undoing tension headaches and increasing one's general pain resistance.
 Exercise Blocks out pain
 How much exercise?
 How to Get that Endorphin High
- Eat a Chile -- Chewing a hot pepper can release endorphins centrally and on the tongue
- Think Positive -- positive thinking can release endorphins that may actually ease pain even if a medication is physically ineffective!
- Work Out
- Have an Orgasm -- One has to run for an hour or do an equivalent amount of exercise for an endorphin high. Great sex has the same effect...and is a lot more fun too!
- Be moved, get pleasure from life -- viewing beautiful art, watching a touching dramatic scene or even listening to an inspiring piece of music can produce endorphins.
- Eat some chocolate -- eating chocolate actually has an impact on your brain that triggers an endorphin release.
- Get spooked -- when people watch scary movies, screech as they plummet down on a roller-coaster or try their hands at Extreme Sports, they actually experience a rush of endorphins.
- Get out into the sun -- researchers say that just knowing it's sunny outside can boost your endorphin production — and your mood.
- Laugh -- Whether it's a quick joke that tickles your funny bone or a long, hilarious romantic comedy, having a laugh produces endorphins that will increase your immune function and make you more resistant to disease.