We are following a dangerous trend. I recently attended an emotionally disturbing and thought-provoking lecture at the University of British Columbia, Vancouver, Canada on the effects of physical inactivity on the occurrence, prevention and management of skeletal fragility and osteoporosis. This fabulous yet alarming lecture, titled Is Anybody Out There Listening, was given by one of Canada’s leading authorities on osteoporosis, Professor Don Bailey, Ph.D. from University of Saskatchewan. Dr. Bailey presented an impressive review of research literature highlighting the urgent need to address the decreasing physical activity patterns of many children in the western world and its effects on future skeletal health. In addition to his scientific review, Dr. Bailey exposed the dysfunctional bureaucratic processes that are crippling the campaign to generate a more active youth population. Below is a brief overview of the recent scientific literature including the growing and menacing trend of physical inactivity sweeping western culture.
Bailey D. Is Anyone Out There Listening? Can Med Assoc J. November 2000.
The purpose of this article was to provide answers to the question of whether the physical activity patterns of many children in the Western world today predisposes them to a greater risk of skeletal fragility and osteoporosis.
Dr. Bailey reports that:
Young bone has a far greater capacity to adapt to changes in the mechanical environment than mature bone.
Prevention of skeletal fragility depends not only on reducing bone mineral loss, but maximizing bone mineral storage during the adolescent growing years.
Measuring peak bone mass development in the early adult years is an excellent predictor of future bone mineral content and fracture risk.
Approximately 25 percent of all adult bone is laid-down during the two critical adolescence years of peak bone growth; this bone surge is equal to the amount of bone loss during the ages of 50 to 80 years.
At least 90 percent of all adult bone mineral content (for life!) is achieved by the end of adolescence.
Within ones individual genetic limits weight-bearing physical activity represents the best opportunity for optimal bone mineral content.
Studies which measured the differences in the limbs of racquet athletes and children with diseases that cause the child to favor one leg more than the other have shown a significant increase in bone mineral content of the preferred or mechanically loaded limb.
Parfitt stated that anyone who remains a couch potato throughout adolescence, will grow bones only strong enough to handle the stresses of a sedentary existence. If much stronger bones are needed for more aggressive activities, it is likely too late to do anything about it.
Here’s the Irony
Dr. Bailey states that the evidence for mechanical loading of the skeleton is not new, in fact, there has been a large volume of research as early as Galileo, which has suggested this the importance of weight-bearing and enhanced bone growth. Montoye et al. put forward this message 25 years ago with urgent proactive recommendations for change. The result, children of today are less active than past generations. In support of these findings, it can be said that we as a society are skeletal casualties of our own technology.
Why are we so slow to respond to this body of evidence?
Researchers postulate the following theories:
The world-wide trend towards urbanization (and less space) reduces the opportunities and accessibility for physical activity.
Television, computers, remote controls, are obvious influencing variables.
Robinson reported children between the ages of two to 17 years spend more than three years of their lives watching television; this does not include all the extra time spent playing video games, watching videos or using a computer.
Bailey reports that schools are dismantling children play stations for fear of incurring injury lawsuits.
Governments are reducing the funds allotted to recreation and physical activity organizations, despite all recent scientific evidence indicating the benefits of exercise.
This physical and economical crisis has also been reported by the US Surgeon General (1996) report on the impact of physical activity on health. Here are a brief synopsis of the studies findings:
- Over 60 percent of the U.S. population is not consistently active.
- Approximately 25 percent of the U.S. population is completely sedentary.
- The participation in physical activity in the U.S. is still declining during adolescence, despite the 12 year effort of several caring organizations.
- Health care costs continue to increase.
- It is predicted that the adolescents of today will have to bear this financial medical burden.
Wanted: Strong Visionaries
The Surgeon General’s 1996 report on health and physical activity, suggests a strong need for leadership to help develop a high-profile physical activity campaign involving all levels of society: personal, family, community, school, organizational, national and political. Strong Visionary leadership is needed to reverse this regressing trend of physical lethargy and inactivity. The following suggestions were given to those in leadership positions:
Fitness and health care professionals (HCP) need to not only encourage a healthier lifestyle, but also act as role models
Families need to weave physical activity into their daily lives
Corporations and small businesses need to recognize their role and responsibility in offsetting this dangerous trend of stagnation and, in turn, promote work-site physical activity
Community planners and leaders need to re-examine whether enough resources and funding exist to maintain/develop playgrounds, community centres., etc. (e.g. $600,000 has been allotted to the REMOVAL of playgrounds on school properties due to liability and lawsuit issues)
School boards need to recognize the powerful impact they have on our future; however, with the understanding that immediate action is needed, starting with a reintroduction of a comprehensive physical activity curriculum
Media and entertainment industries need to use their vast creative abilities to associate an atmosphere of excitement and glamour with physical activity.
Take Home Message
Recognize the urgency of this impending trend; realize the time for action and physical activity is NOW! We have the insight, the means and the power to make substantial changes to the infrastructure of our communities.
So… here’s my question for all fitness professionals and up-and-coming leaders: what role do you wish to play in our society’s future economic stability and health?
- Arlot, ME, Sornay-Rendu E, Garnero P, Vey-Marty B & Delmas PD.1997 Apparent pre and postmenopausal bone loss evaluated by DXA at different skeletal sites in women: The OFELY cohort. J Bone Miner Res 12:683-690
- Bailey DA, Faulkner RA, McKay HA. 1996 Growth, physical activity and bone mineral acquisition. Exercise and Sport Sciences Reviews, volume 24, J.O. Holloszy (Ed.). Baltimore: Williams and Wilkins, pp. 122-166.
- Bailey DA, Faulkner RA, Kimber K, Dzus A, Yong-Hing K. Altered loading patterns and femoral bone mineral density in children with unilateral Legg-Calvé-Perthes disease. Med Sci Sports Exerc. 29: 1395-1399, 1997
- Bailey DA, McKay HA, Mirwald RM, Crocker PE, Faulkner RA.1999: A six year longitudinal study of the relationship of physical activity to bone mineral accrual in growing children: The University of Saskatchewan Bone Mineral Accrual Study. J Bone Miner Res 14:1672-1679.
- Bailey DA, Martin AD, McKay HA, Whiting S & Mirwald R.2000 Calcium accretion in boys and girls during puberty: A longitudinal analysis. J Bone Miner Res. In Press
- Bonjour JP, Theintz G, Buchs B, Slosman D, Rizzoli R 1991 Critical years and stages of puberty for spinal and femoral bone mass accumulation during adolescence. J Clin Endocrinol Metab 73(3):555-563.
- Forwood M, Burr D. 1993 Physical activity and bone mass: exercise in futility? Bone Miner 21:89-112.
- Glastre C, Braillon P, David L, Cochat P, Meunier PJ, Delmas PD 1990 Measurement of bone mineral content of the lumbar spine by dual energy x-ray absorptiometry in normal children: correlations with growth parameters. J Clin Endocrinol Metab 70:1330-1333.
- Hui SL, Johnson CC, Mazess RB. 1985 Bone mass in normal children and young adults. Growth 49:34-43.
- Kannus PH, Haapasalo H, Sankelo M, Sievanen H, Pasanen M, Heinonen A, Oja P, Vuori I. 1995 Effect of starting age of physical activity on bone mass in the dominant arm of tennis and squash players. Ann. Intern. Med. 123:27-31, 1995.
- Melton LJ, Atkinson EJ, O’Fallon WM, Wahner HZ, Riggs BL 1993 Long-term fracture prediction by bone mineral assesses at different sites. J Bone Min Res 8:1227-1233.
- Montoye HJ, McCabe JF, Metzner HL, Garn SM. Physical activity and bone density. Human Biology 48:559-610, 1976.
- Parfitt AM. 1994 The two faces of growth: benefits and risks to bone integrity. Osteoporosis Int 4:382-398.
- Robinson TN. 1998 Does television cause childhood obesity? (editorial comment) JAMA 279:959-960.
- Theintz G, Buchs B, Rizzoli R, Slosman D, Clavien H, Sizonenko PC, Bonjour JP 1992 Longitudinal monitoring of bone mass accumulation in healthy adolescents: evidence for a marked reduction after 16 years of age at the levels of lumbar spine and femoral neck in female subjects. J Clin Endocrinol Metab 75(4):1060-5.
- U.S. Department of Health and Human Services 1996. Physical Activity and Health: A report of the Surgeon General. Atlanta GA: Centers for Disease Control and Prevention, National Center for Chronic Disease Prevention and Health Promotion.