Runners need strength, including the upper body, abdomen, and lower body. Strength keeps you going longer, faster, and . . . stronger. You need arm strength to push you along, chest and abdominal strength to carry you when you're tired, upper leg strength to climb hills, and lower leg and foot strength to push off on each stride. Both short distance sprints and longer distance races (mile, 5K, 10K, 10M, marathon, ultras) require strength. Many runners ignore strength-building exercises, to their detriment. I'm certain one factor that's kept me going all these years is that I've been lifting weights since I was 14.

You can buy dumbbells or disk weights, or fill a couple of plastic jugs with water or sand. A gallon of water weighs about 8 pounds.

Here are 18 strength-building exercises you can do at home.

1. Forward Swing. Stand upright with a weight in each hand. Alternately swing each arm from the center line forward, emulating a running stride.

2. Reverse Swing. From the same position, alternately swing each arm from the center line backwards. This arm swing is more efficient for faster running.

3. Upright Fly. Stand with your arms at your side. Bring the weight up with your arms fully extended. That's harder, yes? Work on it until it isn't harder.

4. Chest Fly. Stand with your arms fully extended. Bring the weight toward your chest. That's hard, too.

5. Waist Curl. Stand with your elbow tucked into your waist. Bend your arms slowly toward your chest, one at a time. After the two harder fly exercises, the curl is actually fun.

6. Military Press. Stand with the weights at shoulder height. Raise one at a time or both as high as you can. Since strength is built by contracting or extending a muscle against resistance, stretch into the sky to increase the strength- building effect.

7. Overhead Curl. Stand with the weights overhead. Curl your arms backwards and forwards. You can go all the way from behind your neck to between your legs. Go slowly, keeping the trajectory under control.

8. Bench Press Without a Bench. Lie on your back with the weights at your shoulders. Lift the weights high. Stretch into the lift.

9. Lying Flying. Lie on your back with your arms extended. Lift the weight a little above the floor and explore your range of motion from high above your head to near your knees, all in the plane of your body.

10. Bent-leg Sit-ups. Lie on your back, feet together and flat on the floor, knees up, back flat. With the weight on your chest, raise your head and chest about 30 degrees -- not all the way. Relax. Repeat 25 to 100 times. Now bring your knees to your chest and do 25 to 100 more. Now extend your legs and point your feet toward the ceiling and do 25 to 100 more.

11. Oblique Sit-ups. Put your legs down, back in sit-up position. Raise your head and chest about 10 degrees. Twist to the right; re-center; twist to the left; re-center; and repeat 25 to 100 times.

12. Squats. For runners, perhaps the best strength exercise of all. Stand with legs spread wide. Balance the weights on your shoulders. Scrunch straight down towards the floor. Rise up. You should feel the burn in your thighs. Repeat 10 to 20 times until fatigued.

13. Lunges. Stand upright with one foot a long stride in front of the other. Balance the weights on your shoulders. Strain forwards. Strain backwards, shifting all the weight from front to back. Repeat 10 to 20 times until fatigued.

14. Splits. Stand in the squats position, upright, legs apart, weights on your shoulders. Lean all the way to the right, stretching the tendons on the insides of your legs. Re-center. Lean all the way left. Re-center. Repeat 10 to 20 times until fatigued.

15. Toe Raises. Stand upright with the weights on your shoulders. Raise your whole body from your toes. Repeat 10 to 20 times. The first few repeats are easy, but they get progressively harder.

16. Dips. Use two banisters or other fixed supports at arm level. Support yourself with two arms. Now let yourself drop and pull yourself up. Your resistance is your body weight. If you can find bars high enough so you can lift yourself clear off the ground and dip, even better.

17. Chin-ups, Pull-ups, Clasp-ups. I have a chin-up bar at home, don't you? Put both hands around the bar and enclose it with your thumb. Raise your whole body from the floor until your chin is level with the bar. Drop down and do it again. With your hands pointed away from you, it's a chin-up; with your hands pointing toward you, it's a pull-up; with your hands together and the bar in the middle between both thumbs, it's a clasp-up.

18. Push-ups. Back on the floor, face down. Put your hands directly under your shoulders. Touch toes to the floor. Push up in one smooth motion, with a straight line from your nose to your toes. Repeat until fatigued.

Note the three classes of weight-lifting workouts.

1. Doing large numbers of repeats with light weights and not much break is essentially an "aerobic" workout.

2. Doing two or three sets of 10 repeats at each station is a "toning" workout.

3. Doing three repeats of the most you can possibly lift, then adding a rack like Bruce Willis in "Unbreakable" until you can lift no more, is a "catabolic" or "breakdown" workout. Body- builders do breakdown workouts about once a week and take 72 hours to recover afterwards. After aerobic and toning workouts, most runners need 48 hours of recovery--every two days. The statement "No Pain, No Gain" is literally true. The pain of a strengthening workout means you are pushing your muscles to their maximum. Don't go beyond the point of pain; find the edge where you can work uncomfortably but acceptably. Then take a full two days to recover before lifting again. The recovery process makes you stronger.