In reply to loz01: To build up, you need to train the 3 types of strength- endurance, power endurance, and power. For endurance, create a footloop so you can do high numbers of reps, do pyramids for example. Power endurance, standard chins, as well as mix in some lock offs- Full lock for 3 sec, 90degrees for 3 secs, slightly bent arms (dont fully straighten) for 3 secs and repeat. For pure power, get some weight on your harness and build up slowly. For goodness sake WARM UP (run, press ups, skipping) or risk majorly screwing elbows. There is alot of info on the web.