Chin-up

So I'm back from trip, and have a goal: I want to be able to do a chin-up by the end of the summer! Before leaving for California, I saw this column in a magazine that gives a run down on how/what to work out in order to be able to do a chin-up in 12 weeks, which is about the time I have left this summer!! The first task is to hold myself at chin level on a bar every day for as long a possible, taking a 1 minute break between each "rep", three times. The magazine says to do it until I can hold myself in that position for 30 seconds at a time, without undue effort (which they estimate will take about 3 weeks). When I read this, I thought the task would be easy... but the honest report on my first attempt is that I was barely able to hold myself in the appropriate position for 5 seconds at a time, and my arms were sore the next day. So starting today, I will try, everyday, to do my "reps". I hope that in 3 weeks time, I will be up to stuff in order to start on my next task!
Oh and p.s. I'll be starting to jog again soon, very soon hopefully!