Exercise of the week!

The humble chin up. I remember this being used as part of a fitness test in high school, back then I could barely do 1, now I'm performing 10 lots of 10 in one workout session!
It comes in 3 basic flavors and can be performed many different ways. Ultimately you have a chin ups, palms facing you. Pull ups, palms facing away but in the same position as a chin up. Or a neutral grip pull up, arms spread like a lat pull down, palms facing away.
You can vary this exercise so much much it's not funny. Weights between legs, slow it down, speed it up, add longer "hold times" at the top, the list goes on, just search the humble chin up on the web and you will no doubt stumble across another way to do it that you didn't know before.
The steps are easy!
1.grip your chin up bar in the desired fashion.
2. Pull yourself up from an arm extended position to a position with your chin (hence the name) up above the bar.
3. Hold and then lower yourself back down.
4. Repeat.

So go ahead and keep your chin up your back will love you for it, and you'll give your arms considerable strength which translates across to multiple other excercises.