Does anybody have suggestions on ways of improving my upper-body strength for a pull-up test? Right now my record is a bit uneven, since on my best day I may be able to do three consecutive pull-ups while on a bad day I can barely manage one--whereas I'd like to be able to consistently do five, and preferably after a reasonably short timeframe (is three months realistic?) If I can get there it'd probably go a long way towards addressing the imbalance between my upper body and its rather more well-developed counterpart below the waist.

Anyway, it seems like I've been creeping my way steadily towards my fitness goals. When I read that the US Marine fitness test calls for a three-mile run in 28 minutes, I thought that'd be a pretty difficult standard to match since I was used to thinking that I ran a lap on the athletic track (400 m) in three minutes and thus it'd take me 36 minutes to do 4.8 km (12 laps). But then I recorded the time I needed to run the first 12 out of the 25 laps (10 km) I do every weekend and got 31 minutes--only 3 minutes slower than the Marines' standard. It shouldn't have surprised me considering how much I had improved my speed and endurance within the last few months, but still it's pretty encouraging to know that I only have one-thirds of the ground left to cover.