Does Exercise Really Build Bones?

Osteoporosis literally means “porous bone”, a disease where bone becomes so fragile it is easily broken, especially after a fall. Almost every one of us is at risk for osteoporosis, while some are of a higher risk. Regardless of our age, gender or race, we are all on the osteoporosis continuum. From the moment we are born, our bodies have been building up bones, which is the internal infrastructure that is expected to support our body for the rest of our lives. However, bones usually reach their peak density in the mid to late 20s, which will then inevitable begins to decline.

While genetics has the limiting factors which determines the degree and speed with which bones deteriorates, all of us are born with certain inherited tendencies that we cannot control. Osteoporosis is a silent disease which will greatly affect and decrease our quality of life, is it possible then to take a more active approach in our lifestyle so that we can prevent these inevitable losses?

We know with certainty that our lifestyle plays a vital role in this process. For instance, we know that smoking, along with unhealthy diet, significantly influences our bone density. We also realise that people who are active in childhood and continue to exercise in their adult years have thicker and stronger bones. The question we are interested to find out is whether we can actually “grow” new bones by engaging in exercise which begun in adulthood?

It was only until recent years, with the advances in modern technology and scientific research that sports scientists are able to show with objectivity and scientific rigor, exercise can make a difference, in particular weight bearing exercises. If you have osteoporosis, engaging in exercise may be able to reduce bone loss or even to put an end to further loss of bone. Simply preventing further decline in bone loss will reduces your risk of fractures and dramatically improves your osteoporosis profile. It has been shown that in some cases, it may even be possible for exercise; especially resistance training and weight bearing exercise, to create new bones, perhaps as much as 6%.

There are numerous health benefits of exercise other than building strong bone and preventing bone loss. Exercise can also improve your stability, reflexes, and coordination, thus reducing the risk of fall and injury. Together with a regular and well designed exercise regime you can even build up the muscle and flexibility to catch and protect yourself even if you do fall. The importance of these skills cannot be emphasis enough for someone who, when diagnosed with osteoporosis, live in constant fear and threat of fracture.

The incidence of hip fracture, which is very often due to osteoporosis (Kerri Winters-Stone, 2005), in Asia has raised two to three folds during the past 30 years. This statistics shows that it will become a major health challenge for the region in the near future as the senior population is increasing.

Being engaged with any exercise program does not denote that you can stop taking the medications that have been prescribed to you by your doctor for osteoporosis. But unlike any medicine, exercise is the only way to make your body stronger, more agile, improved stability, and faster to react to obstacles in your surrounding that might cause you to lose your balance and fall. These are perhaps the most compelling reasons to start an exercise routine if you have osteoporosis.

While we mention about the benefits of exercise for osteoporosis, it need to be understood that in order to achieve the reversal of bone loss, exercise must be of a certain type and level of intensity, and must be appropriate for your fitness level and fracture risk. Contrary to popular belief, walking alone does not help to prevent osteoporosis, nor will it build bone, except in the beginning phases of being totally idle to being a walker. If you have been living a sedentary lifestyle, walking will improve your bone strength initially, and this is definitely the exercise to begin your exercise program. However, after a period of time, there is no further benefit from walking alone once your body has adapt to the training intensity.

Let’s examine why. We need to understand that bone is living tissue and that it responds to intensity, not duration. Meaning to say, it responds to a force greater than it is used to, and not a repetition of the same amount of force. Thus, walking, like all weight bearing activities (running, jogging, Tai Chi, dancing etc), transfer a certain amount of body weight to bones over and over again. Initially, bone responds by improving its architecture, and after a period of time, however, the bone would have adapts to this level of activity and will no longer finds the same amount of exercise a sufficient stimulus for growth.

Strength training, which also known as weight is training or resistance training, has the ability to progressively and continually challenge or overload bones. It doesn’t matter if you are using dumbbells, machines, wrist weights, tubing or manual resistance from a partner, since your body has no preference and it doesn’t discriminate. Thus, when you increase the weight of a dumbbell you use for an exercise, or change to thicker tubing with greater resistance, you “surprise” the bone and force it to adapt to this new stress. Bone then responds by producing more osteoblasts, cells that fill in bone cavities, and bone density improves.

While this may trigger you to go for heavy weight right away, being cautious is still priority as you will not want to end up getting injured before seeing the benefits of your bone growing stronger. Always begin an exercise at a level that is commensurate with your capabilities, and make sure you are able to complete the motion comfortably without any extra weight before adding resistance. Next, be conscious of your health and medical profile. If you have any injuries, arthritis or joint deterioration, a hip replacement, shoulder, back or knee pain, your exercise program needs to be designed in consultation with your personal coach or medical doctor. If you are suffering from either heart disease or hypertension, it might also indicate your need to avoid strenuous weight training. You need to bear in mind that certain medications that make you dizzy put you at increased risk of injury (from falling down or dropping a weight) and should influence your exercise choice.

While most of the osteoporosis research focused on the effects of strength training or aerobics, my many years as fitness professional and senior Tai Chi coach inform me that they are not enough. Looking around gyms I see many men and women who are approaching their senior years flinging their bodies that reflect their hard work, where instead of looking physically great, they instead have stooped, stiff and misaligned posture. Their shoulders are often rounded forward; their walk is without fluidity and not biomechanically aligned.

The tenseness and rigidity I witness are likely compensation for shoulders, necks, knees, or other body parts in pain. In brief, people are exercising with fervor and devotion, while often ignoring their musculoskeletal discomforts in order to improve their strength and cardiovascular fitness, and doing it in such a way that they end up looking old and causing more wear and tear to their joints unnecessary.

Yet there are people who practice Tai Chi where you will see them standing erect, who weave gracefully and confidently as they walk, who present the picture of health. Their youthful appearance, energy and ease of movement belie their real age (they look younger than what they actually are). Tai Chi is a full body workout that stretch and strengthen the body in a functional way as they engage the core (the muscles of the abdominals and back) muscles and also the stabilizing muscles, together with the other fine motor skills that trigger the toning of the different muscles around the body.

In Tai Chi classes, participants learn new and more efficient ways to move, evaporating chronic aches and pains, and exponentially increasing exercise ability, enhancing years of quality lifestyle. (see Optimal Postural Alignment using Tai Chi Principles

An excellent study showed tai chi slowed down the loss of bone mineral density approximately three fold. Another study indicated that people who practice tai chi regularly have higher bone mineral density and better flexibility, muscle strength and balance. Many studies have shown that tai chi reduces falls (Voukelatos Alexander et al., 2007). This is especially important because when people with osteoporosis fall they are more like to sustain a fracture. A fracture can be a very serious problem for example hip fractures have a mortality rate of approximately 50%. It also seriously affects your quality of life. Tai chi has also been shown to improve balance and strength so even if you fall, you have a lesser chance of serious injury (Mau-Roung et al., 2006).

Regardless of any health constraints you may have, just a little exercise can yield significant benefits. In addition to its positive effect on bone, exercise enriches your life by making your daily physical activities so much easier. Carrying groceries, cleaning the home, climbing the stairs, picking something up off the floor, or even getting out of a chair don’t need to be daunting propositions anymore. Improvement may be just around the corner. What you find difficulty today can become easy in a matter of weeks.

Bridging the science of research with practicality and addressing the authentic lives of people is what I wish to share in this article. That’s why, in addition to strength training and aerobics, your will find exercises from the realms of Tai Chi beneficial and contributes to a bone-building approach. When combined, they form a powerful fusion that just can’t be beat (Dianne Daniels, 2008)

References

ARTHUR E. CHAPMAN (2008) Biomechanical Analysis of Fundamental Human Movements, United States, Human Kinetics.

BIRKENHAGER-FRENKEL, D. (1988) Age-related changes in cancellous bone structure. Bone Mineral 4:197.

DIANNE DANIELS, M. A. (2008) Exercise for Osteoporosis, New York, London, Hatherleigh Press.

DING, M. (2000) Age variations in the properties of human tibial trabecular bone and cartilage. Acta Orthop Scand Suppl 292:1.

GRIMSHAW, P., LEES, A., FOWLER, N. & BURDEN, A. (2007) Sports & Exercise Biomechanics, New York, Taylor & Francis Group.

KENNEDY, C. A. & YOKE, M. M. (2004) Methods of Group Exercise Instruction.

KERRI WINTERS-STONE, P. (2005) Action Plan For Osteoporosis – Your guide to stronger, healthier bones, USA, Human Kinetics.

MAU-ROUNG, L., HEI-FEN, H., YI-WEI, W., SHU-HUI, C. & L, W. S. (2006) Community-Based Tai Chi and Its Effect on Injurious Falls, Balance, Gait, and Fear of Falling in Older People. PHYS THER, 86, 1181-1201.

MOSEKILDE, L. (2000) Age-related changes in bone mass, and strength – effects of loading, Z Rheumatol 59 Suppl 1:1.

RISSER, W. (1990) Bone density in eumenorrheic female college athletes. Med Sci Sports Exerc 22:570.

SNOW-HARTER, C. & MARCUS (1991) Exercise, bone mineral density, and osteoporosis. Exerc Sport Sci Rev 19:351.

STEIN, M., THOMAS, C., FEIK, S., WARK, JD & CLEMENT, J. (1998) Bone size and mechanics at the femoral diaphysis across age and sex. J Biomech 31:1101.

SUSAN, J. H. (2003) Basic Biomechanics, Fourth Edition

TANNO, M., HORIUCHI, T., NAKAJIMA, I., MAEDA, S., IGARASHI, M. & YAMADA, H. (2001) Age-related changes in cortical and trabecular bone mineral status. A quantitative CT study in lumbar vetebrae Acta Radiol 42:15.

VOUKELATOS ALEXANDER, M. P., CUMMING G ROBERT, P., LORD R STEPHEN, D. & RISSEL CHRIS, P. (2007) A Randomized, Controlled Trial of tai chi for the Prevention of Falls: The Central Sydney tai chi Trial. Journal of the American Geriatrics Society, 55, 1185-1191.

WOLF, S., KUTNER, N. & GREEN, R. (1993) The Atlanta FICSIT study: two exercise interventions to reduce frailty in elders. Journal of the American Geriatrics, 41, 329-332