WHILE WE SIT AND TALK, work and breathe, architects are constantly at work in our bones. Consisting of bone-forming cells (osteoblasts) and bone-removal cells (osteoclasts), these construction engineers take part in what you might call the Battle of the Bone — a tug-of-war over your skeleton.
Simply put, the bone removers are winning. After you reach maturity they work faster, stealing up to 4 percent of your bone each year after menopause. Meanwhile, the bone formers manage to crank out new bone at only a 2 percent rate. The pluses and minuses don’t add up in our favor. And too often the results is osteoporosis, the bone-thinning disease that can lead to “spontaneous fractures.”
Enter a secret weapon to assist the bone-forming cells and help bring that equation back into balance: resistance training. We told you about it in our December 1990 article “Interior Bodybuilding.”
All-around physical activity can maintain and even increase bone mass. But what can resistance training do for your bones? Cutting-edge research is beginning to suggest that resistance esxercises — primarily those that target specific osteoporotic hot spots — may actually prevent bone loss and stimulate an increase in bone mass in those vulnerable areas. This is new territory, but here’s a lhint of what preliminary research indicates so far:
* In a recent study, pushing exercises using the forearm helped boost bone in that area in a group of 70-year-old osteoporotic women. The women pushed against a wall or clasped their hands together and pushed them against each other in three weekly workouts for five months. They experienced a 3.8 percent increase in bone in the distal radius (wrist), while the nonexercisers saw a decline of 1.9 percent (Calcified Tissue International, February 1987). “Even in a short period of time, they saw increases in an area of bone where many fractures occur,” says Sydney Lou Bonnick, M.D., director of osteoporosis services at the Cooper Clinic, in Dallas.
* In another study, this time of middle-aged women, exercise helped stave off bone loss that usually accompanies the middle years. The four-year study included use of light weights and resistance bands to strengthen the upper body. Ten of the 18 areas of bone mass measured showed significantly reduced bone loss among the xercisers. Projected over 20 years, the bone mass of the ulna (the forearm bone on the side of the little finger) normally would decline 25 percent. In the exercise group, that steep decline was projected to tilt up in a big way — slowing to just 5 percent (Calcified Tissue International, 1989, vol. 44, 312-21).
* Studies of the racket arms of tennis players show a much higher bone mass in that limb than the nonracket arm (Journal of the American Medical Association, vol. 244, no. 10). “The bone density is greater in that arm simply because it encounters more resistance,” says Kenneth H. Cooper, M.D., president and founder of the Institute for Aerobics Research. “Any resistance exercise targeting a bone tends to do that.”
Weight-bearing exercises like stair climbing and walking — targeting the lower limbs — have also caused significant increases in bone mass. Small increases in the spine have been shown to occur, even though the resistance exercises used didn;t target that crucial zone. These increases (less than 1 percent in a group of 34 women at Texas Woman’s University) may be considered insignificant in this 12-month study. But over a sustained period they could add up. Even more, gaining or maintaining bone mass means one simple yet monumental thing — you aren’t losing any. In that sense, it’s not insignificant that you’re slowing — even reversing — one of the so-called inevitables of aging.
Bone experts agree. “Exercise may be the greatest stimulator that bone ever gets, and may maintain and even increase your bone mass,” says Everett L. Smith, Ph.D., director of the biogerontology lab, department of preventive medicine, University of Wisconsin. “It may help maintain a younger bone — a younger bone that is more resistant to fracture.”
HOW TO HIT THE HOT SPOTS
For a full-on preventive attack against the onslaught of osteoporosis, we’ve asked the top researchers for a little advice on protecting crucial parts of the skeleton — the hips, spine and wrists. These areas are the most vulnerable and most common victims of osteoporotic fractures, with fractures of the hips and spine resulting in the most illness and death. Wrist fractures are obviously much less life-threatening, but are often painful and delibitating.
With the experts at hand, we’ve come up with an exercise program targeted at those flash points of fracture, to prevent these breaks from happening and bone from leaving home. (Remember, though, that exercise is not a substitute for other osteoporosis-prevention measures, such as a good diet and proper medical care.)
And don’t forget the main benefit of resistance training — it builds muscle. By boosting strength, you may reduce the risk of falling and the force of impact if you do. That alone may cut the risk of many osteoporotic fractures. So while you’re working the bone, you’re also creating and improving upon a fracture-proofing jacket of muscle — surrounding your skeleton and providing a cushion against falls.
Keep the spine in line. For the spine, back exercises are key. “For a beginner, a good thing to start off with are floor exercises or stretches in which you work at arching your back,” says Dr. Bonnick. They’re easy to learn and can be done anywhere with relative ease.
The next rung up the spine-protecting ladder might be back extensors. This calls for some mechanical assistance. “The back-extension machine, which is found in almost every health club, is probably the most underused machine and probably one of the most effective,” says Dr. Bonnick. Dr. Bonnick believes this machine may be the most important tool in tageting the vertebrae. Once you have mastered these exercises, you might feel confident enough to try a tougher one, the squat. “If you really want to stimulate the spine, you need an exercise that affects the whole structure,” says William Kraemer, Ph.D., director of research at the Center for Sports Medicine, Pennsylvania State University. “Squats improve upon bone mass by providing adequate loading on the spine and hip.” Squats are easier said than sweated. But if done slowly and carefully, they can be accomplished and t heir benefits reaped.
Assist your wrist. “Spine and hip fractures get most of the attention because they are the most devastating,” says dr. Bonnick. “But wrist fractures are extremely common and very painful.” Dr. Bonnick has her patients target that area with wrist curls. “I have them do two or three sets of wrist curls, with plenty of rest in between” she says. Rest is important with any exercise than requires a lot of gripping (this includes riding an exercise bike, for example). “Gripping for a long period of time without rest can boost blood pressure,” says Dr. Bonnick. When doing wrist curls, do two or three sets with no more than eight repetitions for each set.
Get hip to your hips. For this major target zone, squats can also help. But to get an even better bulls-eye on the bone, Dr. Bonnick advises hip flexion and extension, and hip adduction and abduction. These exercises call for stretch bands, pulleys or tubing. Health clubs usually have pulley machines that allow you to do a number of exercises that work the hip.