Your Targeted Exercise Guide for Osteoporosis Prevention
Honest Health News: Osteoporosis, or "porous bone," characterized by low bone mass and structural deterioration of bone tissue, is known to increase 40+ million Americans' risk of fractures, falls, and premature mortality. Readers learned the nuances of preventative nutrition in Part I, "What You Don’t Know about Calcium and Osteoporosis Prevention," but preventative exercise is considered perhaps even more important. How can we prevent osteoporosis using the most proven, scientific, and targeted exercise practices?
JP: Your two exercise objectives should be to strengthen your bones overall and to target the bones in the areas most prone to fracture.
1. To strengthen your bones overall, you’ll want to do regular weight-bearing aerobic activity plus weight training. Regular physical activity may help prevent fractures by preserving bone"Building muscle is one of the most effective means of preventing falls."mass and/or by reducing the incidence of injurious falls. And building muscle is likely one of the most effective means of reducing falls and fracture incidence, because it positively affects multiple risk factors for fracture, such as low bone mineral density and slow walking speed. In short, by building your muscle mass, you’ll also reduce your risks of falling.
2. To bolster the bones in the most vulnerable fracture sites—the spine, hip, and wrist—use targeted strength-training exercises.
How Aerobics Builds Bone
HHN: Why exactly does aerobic exercise help in osteoporosis prevention?
JP: Our bone is living tissue—in a state of constant turnover: Some bone cells (osteoclasts) are breaking down old, weak bone, while other bone cells (osteoblasts) are building strong, new bone. In this bone remodeling process, old bone is constantly being replaced with new cells to strengthen it.
Bone strengthening can also happen when both ground-reaction forces (the force with which your body weight hits the ground) and mechanical forces act on the bone."When bone feels a repeated force, it increases bone mass to become stronger and better tolerate the strong muscle contractions."Muscles are attached to bones, so when a muscle contracts, the force it generates gets transmitted to its attached bone, bending that bone. When the bone feels a repeated force, it responds by increasing bone mass so as to become stronger and better tolerate the strong muscle contractions.
In short, appropriate exercise stimulates the bone remodeling process to maintain bone strength and offset bone loss.
HHN: For osteoporosis prevention you’ve specified "weight-bearing" aerobic activity, as opposed to aerobics in general. Why?
JP: Some of the first evidence that weight-bearing exercise was important to the human skeleton came from observations of bone loss in astronauts. When astronauts went into space, they lost bone rapidly-at a rate of about 1% per month, 12−24 times faster than the usual bone-loss rate from aging.
When we are upright, the invisible force of gravity puts stress on our bones, which helps them maintain mass. But when that force is removed, through space travel, or more commonly immobilization (as when a leg is in a cast), or long periods of bed rest (resulting from prolonged illness) or inactivity, we can lose bone mass.
Similarly, exercises such as swimming and cycling, when our body weight is supported by the water or the bike"Many male master cyclists had low bone mineral density and a high fracture risk."rather than gravity, don’t appear to strengthen our bones. One 7-year study of competitive male master cyclists found that many of them had low bone mineral density and a high fracture risk. Another study showed Tour de France bikers having 10% less bone mineral density in the lumbar spine, 14% less in the hip, and 17% less in the Wards' triangle (within the femur).
Aerobic Workouts That Work
HHN: Which weight-bearing aerobic exercises are best for reducing osteoporosis risk overall?
JP: Many weight-bearing aerobic exercises have been shown to positively affect bone, among them fast walking (>5 mph), jogging,"Fast walking, jogging, stair climbing, dance, and jumping rope positively affect bone."stair climbing/stepping, aerobic dance, and jumping rope. Other common weight-bearing activities, such as elliptical training, cross country skiing, and hiking, haven’t yet been studied for bone mineral density effects.
Keep in mind that what exercise is best for someone else may not be best for you. Stay safe by choosing exercises appropriate for your health, muscle strength, and bone/joint integrity. (Note: If you have been diagnosed with osteoporosis, be sure to read to the very end of this article.)
HHN: For bone impact, you specified "fast" walking, at a minimum of a 5 mile/hour pace. Why? Does slower walking have no effect?
JP: The key to aerobic bone-building is to maximize the ground reaction forces, or the force with which your body weight hits the ground. For this reason, aerobic training must be intense enough to put high forces on our skeletons.
To get there, the research shows it’s most effective to exercise at a rate of 60% - 85% VO2 max (the maximum rate your body consumes oxygen), which generally translates"The key to aerobic bone-building is to maximize the force with which your body weight hits the ground."(depending on your age and the energy expended) into about 76% - 92% of maximal heart rate (number of heartbeats per minute when your heart is working at its maximum, approximately 220 minus your age). If this approach is too detailed for you to apply, no worries. Here’s an easier way: Self-assess your exercise. It should be "vigorous," which the American College of Sports Medicine (ACSM) defines as "somewhat hard to very hard" for you.
In contrast, "moderate" exercise, a self-assessment of "fairly light to somewhat hard," does not provide enough force on our skeletons. When researchers compared two groups of formerly sedentary women aged 50 — 75, those who exercised at moderate intensity for 225+ minutes/week and those who participated in an ongoing stretching program, after a year’s time no significant differences in bone mineral content or density emerged. (The exercisers had, however, lost more weight.)
Now, when it comes to walking, if you’re already a walker, that’s great, keep it up. Large survey"Walking at a moderate pace does not affect bone mass—probably because the skeleton doesn’t view walking as a new challenge."studies show that women who walk regularly are less likely to get fractures than inactive women. However, the research also shows that walking at a moderate pace, such as at 3 miles an hour, does not affect bone mass—probably because the skeleton doesn’t view walking as a new challenge, since most of us walk during our day.
How, then, do you challenge the skeleton enough to increase bone mass while enjoying your walk? You don’t have to maintain a speedy pace throughout. If you’re in good enough physical condition, two very good approaches are to add bursts of very fast walking and to walk briskly up hills. During these spurts, self-assess: Is this vigorous? Does this feel "somewhat hard to very hard"?
Try to engage in these vigorous bursts for at least 1 hour a week, as recommended by the Healthy People’s 2010 Public Health Initiative and the American College of Sports Medicine.
HHN: What kinds of positive effects can people expect from these weight-bearing exercises?
JP: Positive effects range from slowing bone loss to gaining up to 3% bone mass. The average benefit across studies of pre- and postmenopausal women is a 1% gain in bone mass, which, if maintained over time, may significantly reduce fracture risk.
BEST Combo Training for Bone-Building
HHN: You’ve also highlighted the importance of resistance training in osteoporosis prevention. What do we know about best overall practices for bone-building?
JP: We know from the 1995 — 2001 Bone Estrogen Strength Training (BEST) study out of the University of Arizona that the right combination of weight-bearing and progressive resistance exercises can build bone."We know from the Bone Estrogen Strength Training (BEST) study that the right combination of weight-bearing and progressive resistance exercises can build bone."The researchers randomly placed 266 sedentary women into either a control group or an exercise group. The exercisers performed specific weight-bearing and weightlifting exercises 3 times/week, and progressively increased the amount of weight lifted over time (year one under researcher supervision, the next 3 years on their own). Meanwhile, all the women received calcium citrate supplements (800 mg daily in divided doses).
At the study’s end, the exercise group had significant improvements in bone mineral density, and specifically at the skeletal sites most at risk for fractures.
HHN: What was the BEST bone-building regimen?
JP: Here are 2 core elements:
Aerobics: 20 minutes per session, 3 times a week. Participants either walked with a weighted vest or did a circuit of skipping, jogging, jumping, and hopping. Then everyone did step-climbing, either on a machine or on stairs.
Strength-Training: 25 minutes per session, 3 times a week. Participants did 2 sets and 6−8 reps of these 6 large muscle-group exercises:
1. Back Extension (no equipment needed)
2. Lat Pull Down (see at-home version One Arm Lat Row below)
3. Leg Press (see at-home version Squat with Weights below)
4. One-Arm Military Press (see dumbbell-free version below)
5. Seated Row (see at-home semi-substitution Lat Row with Bands below)
They did some other strengthening and balancing exercises as well; for details, download a free PDF of the study.)
3 Bone-Building Hacks
HHN: With this protocol, the women were not doing many reps, only 2 sets of 6−8 reps. Why?
JP: Lauve Metcalfe, MS, FAWHP, CWC, who directed the intervention for the BEST research project, explains why: "Our effects were found in the 6 exercises you listed, and I must emphasize that the improvement in the bone and muscle was due to the strain rate on the bone/muscle group due to the heavy weights lifted. Our focus was lifting the heaviest weights possible, in good form, for 6−8 repetitions, 2 sets. Previous research focusing on strength training with postmenopausal women found that bone mass can be significantly increased by a regimen that uses high-load (heavy weight), low repetition (up to 8 reps) resistance exercises, in comparison to low-load (lighter weight), high-repetition (20 reps) exercises."
In short, the research shows that bone tissue responds best to these 3 hacks:1Relatively few repetitions (up to 8). With prolonged exercise, bone loses its mechano-sensitivity, or its ability to "hear" that you are still exercising, and to act accordingly.2New, progressively more challenging stimulations that maximize your bone’s continued responsiveness to your exercise. Thus, it’s important not to stick with comfortable light weights. Try to increase your weight/resistance load whenever you can do so gradually and safely.3Lots of rest in between sessions. When given enough rest, bone "gets the message" of new stimulation and begins to change in mass and strength—and a little increase in bone mass on the outer surface of the bone can have a huge impact on bone strength. This animal study showed that a 4-hour rest period almost doubled bone formation. One day’s rest is even better: After 24 hours, 98% of bone mechano-sensitivity returned.
Finally, consider this animal study (animals being the only way the research study can be controlled), in which researchers compared 3 ways of getting to 360 bone-exercise repeats/cycles: 1 a daily session of 360 cycles, 2. four daily sessions of 90 cycles, and 3. six daily sessions of 60 cycles. The two multiple-session regimens increased bone formation significantly more than the single session.
Bone-Building at Home
HHN: That really helps. Now, some of the particular strength-training exercises recommended—lat pull down, leg press, and seated row—are done on gym equipment. Are there alternatives, using inexpensive equipment, for readers who want to follow this regimen at home?
Lat Pull Down Substitute: One-Arm Lat Row1) Stand sideways to a chair and place your left hand on the chair back for support. Assume a staggered lunge position per above, with your left leg forward and your front knee bent over your ankle.
2) With your back straight, lean forward slightly from your hip. Hold a free weight (or weighted household object such as a water bottle) in your right hand. Your arm should be straight, directly below your shoulder, and your palm facing in.
3) Draw in your shoulder blade toward your spine. Now, while you exhale, bend your elbow to 90 degrees and pull the weight up to your waste.
4) Inhale as you slowly return to the start position.
Finish your reps, then switch sides and repeat.
Leg Press Substitute: Squat with Weights
1) Hold a free weight (or a household object such as a water bottle) in each hand, arms straight by your sides. Stand with your feet parallel, shoulder- width apart. Plant your heels on the floor and shift your weight back onto them so that you can lift your toes easily.
2) Inhale as you slowly bend your knees to 90 degrees, reaching back with your hips as if you were going to sit down. Allow your torso to lean forward, but keep your spine straight and your eyes forward. Pause briefly, then exhale and tighten your glutes as you push through your heels to return to the start position.
Seated Row (Partial) Substitute: Lat Row with Bands
1) Hold the band with your arms extended in front of you, palms facing in. Squeeze your shoulder blades down and together.
2) Exhale as you pull the band into the sides of your waist, keeping your elbows in close to your body. Inhale as you release back to start.
Note, however, that Seated Row is the one cited gym exercise from the BEST study without a comparable progressive weight-loading version you can do at home. Using Lat Row with Bands at home is better than not doing the exercise, but it isn’t the BEST routine for building bone.
Also, keep in mind that you can do the One-Arm Military Press without dumbbells. Just substitute a household item such as a water bottle or half gallon jug for the weight.
Why Multiple Exercises Matter
HHN: This is quite a range of exercises. In effect, you’re saying that walking, or another exercise people may like to do, is unlikely to target all of the most common fracture areas, right?
JP: That’s true. For example, studies of walking show it can increase bone mineral density (BMD) in the hip area, but not in the spine. Similarly, a review of jumping exercises found that jumping significantly increases bone mineral density in the hip, but not the spine.
Generally, lower body exercises, such as walking and jumping, will improve bone mass in the hip. Upper body strength-training exercises, such as military press and lat pulldown, will improve bone mass in the spine.
Therefore, your best preventative approach is to do a full range of weight-bearing exercises that target the different body areas.
HHN: Do we know for a fact that targeted exercise stimulates site-specific improvements in bone density—in contrast to weight loss, where you don’t have control over where the weight comes off?
JP: Yes, studies of athletes have shown site-specific improvements in bone density. One classic study"Researchers found significantly greater bone mineral density in tennis players' playing arm than in the other arm."compared the bone mineral density (BMD) in the playing arms of tennis players compared to their other arms and found significantly greater BMD and 20% greater arm tissue mass in the players' dominant playing arms. In contrast, there were no significant differences between arms in a control group of non-athletes.
The 3 Most Common Fractures
HHN: OK. So let’s focus on the most common osteoporosis-related fractures that might be avoided by preventative exercise.
JP: The 3 most common sites of osteoporotic fractures are:
1. Spine: 40% of fractures happen in the spine. They usually occur with minimal trauma from simple acts of daily life such as coughing, sneezing, lifting, and bending over. There may or may not be any pain. The vertebrae may be collapsed or compressed. A loss of height of more than 2″ is a clinical marker for this, as is the stooped posture often associated with osteoporosis.
2. Hip: 25% of fractures occur in the hip (typically in the femoral neck and trochanteric"Half of people who have a hip fracture lose the ability to walk independently, and 20% die within a year."regions; the term femoral neck relates to a hip area and not the human neck). Hip fractures typically result from a fall, but if the bone is weak enough, it can fracture spontaneously without any external event, what’s known as a "fragility fracture." Of the 3 most prevalent fractures, hip fractures are the most debilitating: 50% of people who experience one lose the ability to walk independently, 1/3 become totally dependent, and as many as 1/5 die within a year of a cause related either to the fall or to the surgery.
3. Wrist/Forearm: 15% of fractures occur in the forearm/wrist (the injured area is in the distal radius area of the forearm, but because the fracture is near the wrist joint, it often called a wrist fracture). It’s the most common fracture before the age of 75, often the result of an outstretched hand to break a fall.
Note, though, that randomized, controlled trials have not measured how effectively any targeted exercise reduces fractures in these and other areas. Such studies would be extremely challenging to conduct, in part because of the large sample size and long periods of observation required.
However, it is broadly accepted that targeted exercise has a specific loading effect on bone, and that we certainly can strengthen the areas vulnerable to fracture.
BEST Exercises for the Spine
HHN: What kinds of exercises can help strengthen each of the 3 most vulnerable areas? Let’s start with the spine.
JP: For the spine, the most effective protocols we know are the 4 upper body resistance exercises that worked in the BEST study:
1. One-Arm Military Press, using dumbbells or water bottles
2. Lat Pull Down, or One Arm Lat Row at home (described above)
3. Back Extension, no equipment needed
4. Seated Row. or, as a semi-substitute, Lat Row with Bands at home (described above)
Best Exercises for the Wrist
HHN: What are the best ways to strengthen bone density in the wrist area?
JP: All upper-body weight-training exercises in which you hold a weight or bar in your hands will transmit force through the wrists, which are supporting the resistance.
1. Push-ups are weight-bearing through the wrists and forearms.
2. Wrist curls also target these areas.
3. Plus there are flexible rubber bars that you can bend and twist to strengthen them, too.
Best Exercises for the Hip
HHN: And what are the best approaches to strengthening bone density in the hip?
JP: Weight-bearing aerobics, strength-training, and being generally physically active can all make a difference:
1. Jumping exercises significantly increased bone mineral density in the hip (per this review) and significantly improved hip bone mineral density in comparison to strengthening exercises (per this study). Of the jumping exercises, jumping rope has been studied the most.
2. Walking: A 6-month walking program significantly improved bone mineral density in the hip (per this review).
4. Leg Press, which also helped built bone in these areas in the BEST study. At home, substitute Squat with Weights per above.
5. General Physical Activity. There’s considerable evidence from epidemiologic studies that"Jumping exercises significantly increased bone mineral density in the hip."inactivity is a risk factor for hip fracture. People who report being physically active are 20% - 40% less likely to have hip fractures compared to those who report being sedentary. And those who engaged in exercise had 1.03% less hip-bone loss on average than those who didn’t (see this review).
Developing Habits, Dealing with Diagnosis
HHN: Is there anything else should readers know about osteoporosis prevention?
JP: First, don’t expect immediate results. Because the bone formation process takes about 6 months, it may be half a year or more before any new exercise regimen may improve bone mineral density.
Second, develop a regime that you will want to maintain throughout your life. Research shows that ongoing exercise is necessary to develop and maintain bone density gains; when the exercises are discontinued, any gains are lost.
Third, as part of your regimen, include exercise time with your kids and grandkids. Research"Childhood physical activity predicted total bone mineral content better than older adults' current activity levels."(here and here) shows that adolescence is the best time to build bone mass In this study, physical activity during childhood predicted total bone mineral content better than older adults' current activity levels. So, if you exercise with kids, everyone will benefit.
Fourth, once your routine becomes a habit, consider expanding it to include balance exercises. These will bolster your lower body’s stability, which has been shown to help with fall prevention.
Fifth, if you are diagnosed with either osteopenia (low bone density not yet osteoporotic) or osteoporosis, it’s vital to help yourself through exercise. In my experience, some people are so distressed by a diagnosis, they become paralyzed and afraid to exercise for fear of further damage, when the right exercises can be safe and effective.
Please be aware that some of the exercises I’ve discussed here will no longer be appropriate for you. Depending on your condition,"If you’re diagnosed with low bone density or osteoporosis, it’s vital to help yourself through exercise. Seek professional guidance."you can switch to low-impact, weight-bearing activities such as walking, marching in place, and/or using an elliptical machine. If your osteoporosis is severe, avoid any jarring movements with rotation (such as tennis or bowling), any activity that flexes the spine (such as crunches or toe touches), and any exercise that may increase the risk of falling. It’s prudent to seek professional guidance as to which exercises are best for you.
Finally, if you want to learn more, I recommend Dr. Kerri Winters-Stone's book, Action Plan for Osteoporosis, which discusses, among other topics, how to tailor an osteoporosis-prevention exercise program to your needs and abilities. Another fine option, which delves further into the BEST exercise protocol within the gym setting, is The BEST Exercise Program for Osteoporosis Prevention, created by 6 authors involved in the research study, including study director Lauve Metcalfe.
The ultimate goal of exercise for osteoporosis is to reduce the risk of falls and fractures. It is clear that strength not only helps conserve bone mass, but also maintains muscle mass and improves balance, both of which prevent falls.
It’s never too late to begin an exercise program that’s appropriate for your overall health, muscle strength, and bone/joint integrity. The sooner you do, the longer you will benefit.by