The Nerd's Guide to Pull-ups

http://www.bbc.co.uk/dna/h2g2/A27636528

"Every time a muscle contracts and releases, it sends out, among other chemicals, the protein IGF-1, which travels across the blood-brain barrier into the brain. There, it stimulates the production of (among other chemicals) brain-derived neurotrophic factor (BDNF). BDNF happens to be essential for higher thought processes. Regular exercise leads to higher levels of BDNF, which causes nerve cells to start branching out and connecting in new ways; another way of saying the brain learns. So if you're having trouble wrapping your brain around relativity, pull-ups are a relatively good study strategy."

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"Pull-ups will be a great lesson in anatomy. The morning after your first workout you will not only discover which muscles you were using to exercise, but also what other mundane tasks those muscles perform each and every day. It will be painful but educational."

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Tip 6: If you aren't getting stronger between workouts, either you're not working out hard enough or you're working out too hard. You're a nerd — think of it as the trajectory of a parabola; you can plot an optimal workout with a bit of calculus.

If you're a high-intensity-workout person, resting every other day might not be rest enough. Taking off a week every five months or so will let your body finish repairing the tissue; you'll be surprised to find you gain strength by just surfing the Internet.