In no way is the upperbody as important, as strengthening both
The Posterior & Anterior Chain. Emphasis should be placed here when it comes to strength training. The Posterior Chain consists of the (Hamstrings, Glutes, Hips, Legs, Lower back/Erector spinae), “A strong man is strong on the back of his body.” The Anterior Chain consists of the (Abdominal muscles, the Illiopsoas, Hip flexors and the Rectus Femoris). Front & back of the core/lowerbody.
When it comes to an upperbody workout, I feel too many people perform way too many exercises, too much volume, when a lot of time could be saved. (Although in no way is any respect lost)
A good upperbody workout will be based around one compound exercise, either: 1. Bench press or 2. Floor press or 3. Indoor Arm cycle. A compound exercise is one exercise that is literally going to hit all the muscles in the upperbody.
Then all you need is 2-3 additional strengthening exercises something for the upperback/lats (One-Arm Dumbell Rows?) and shoulders/deltiods/chest (Upright Rows/Press-Ups?) Yes, this would be only 3 or 4 exercises for the whole workout (2-5 sets per exercise/5-12 reps per set). No strength endurance sets/reps here.
Don't ever forget the core of the body. Not in a million years. That is where real power is generated.
An upperbody routine may look a little something like this:
Bench press: (Shoulders/deltiods/chest): (3-5 sets x 8-12 reps)
Upright Rows: (Shoulders/deltiods/traps/abs) (x-5 sets x 12 reps)
Push-Ups: (Shoulders/triceps/deltiods (x-5 sets x 30+ reps)
One-Arm Dumbell Rows: (Upperback/Lats) (x-4 sets x 8 reps)
I hope your not getting any images of what a bodybuilder looks like. Far from it. Your not going to kill yourself, just work hard enough for your body to register a new stimulus.
Upperbody doesn't take preference over strengthening the Posterior chain or The Anterior Chain. Gains in great strength can't come via just cycling & running alone.
Use
http://www.youtube.com/ &
http://www.exrx.net/Lists/Directory.html for exercise instruction.