Do this sequence three times a week, with one rest day between.
Squat Pyramid with Shoulder Press-Ups
For squat form, see the Back Squat test. For press-ups, hold dumbbells at your shoulders, then press straight up over your head. Do ten squats, followed immediately by ten press-ups. Then do nine squats followed by nine press-ups, and so on, until you get to one. Err on the light side with the weights; both moves should start easy but be very tough by the end.
Do ten pull-ups, then nine, then eight, and so on, until you get to one, resting a minute between each set. Once you reach exhaustion, have a buddy boost you by lifting your feet slightly so you can complete the set.
Hauling a heavy pack uphill, clanging your mountain bike down rough singletrack, carving a super-G turn on an icy slope strength is about controlling your body and managing the forces that come to bear on it. But make strength training a focus only after you've developed flexibility, core stability, and long-range power. It's the armor you put on last. (Note: If you're new to lifting, have a trainer run you through these tests and get you started on any of the Remedial Training exercises.)
a. Bench Press
On a horizontal bench, lower the bar to your sternum and lift all the way back up. The goal is to press 85 percent of your body weight ten times with perfect form (no back arching or chest bouncing).
b. Back Squat
Using a free-weight squat rack, load the bar with the most weight you can handle while maintaining perfect squat form (as a starting point, try lifting 50 percent of your body weight). Support the bar across your upper back, an inch or two above the tops of your shoulder blades. Place your feet shoulder width apart, with your knees above your toes, and look forward. Lower by easing your butt back, while keeping your lower back arched, not rounded. Continue lowering until your thighs pass parallel. Stand back up. You pass if you can lift 100 percent of your body weight ten times, with perfect form.
Using an overhand grip, hands placed a little more than shoulder width apart, pull yourself up until the bar is at the base of your neck really, that far. Repeat. If you complete 15 without releasing the bar, you pass.