I am doing a super-set, high-volume, count-down upper body workout since the riding season is winding down. I am trying to prevent getting out of shape during the off season. Super sets are when you do opposing resistance exercises, one right after another. High volume means lots of reps. The count down method allows you to keep working even as the muscles get fatigued. It gets you pumped up in a short amount of time. I am doing this work out every other day and using my Total Gym on the alternate days in circuit training mode (12 exercises, no rest in between). Now that it's colder I only ride every second or third day.

The workout is like this:
18 chin ups, no rest, 36 push ups, 1 minute rest
16 pull ups, no rest, 32 push ups, 1 minute rest
14 chin ups, no rest, 28 push ups, 1 minute rest
12 pull ups, no rest, 24 push ups, 1 minute rest
10 chin ups, no rest, 20 push ups, 1 minute rest
10 chin ups, no rest, 20 push ups, 1 minute rest
8 pull ups, no rest, 16 push ups, 1 minute rest
6 chin ups, no rest, 12 push ups, 1 minute rest
6 pull ups, no rest, 12 push ups, 1 minute rest

100 total chin/pull ups, 200 total push ups

This is followed by hanging upside down with gravity boots and doing 20 fully inverted sit ups and fully inverted 24 side crunches.

Pull ups are hands wide, palms facing away, like lat pull downs. Chin ups are hands shoulder width, palms facing me, like biceps curls. The brief one minute rest between super sets allows the lactic acid to wash away and allows the muscle to reoxygenate, so you are not limited by lactic acid build up.

If you can't do this many pull ups, start at a lower number or do them on a Total Gym (at a fraction of your body weight).

I am seeing improvement. In about 10 days I went from 72/144 reps to 100/200 reps. As I get stronger I can start at an even higher number.