Taru Tervo

Constant Adaptation of Bone to Current Physical Activity Level in Men: A 12-Year Longitudinal Study

CONTEXT A high peak bone mineral density (BMD; grams per square centimeter) could reduce the risk of osteoporosis related fractures later in life. OBJECTIVE This 12-yr longitudinal study investigated whether a high BMD from previous high physical activity is maintained with reduced activity later in life. DESIGN This was a longitudinal study. PARTICIPANTS Three groups were investigated with a mean age of 17 yr at baseline; 51 athletes who stopped their active careers during follow-up (former athletes), 16 who were active throughout follow-up (active athletes), and 25 controls. MAIN OUTCOME MEASURES BMD of the femoral neck, total body, and lumbar spine were examined five times during the 12-yr follow-up period. RESULTS After adjustment for age, weight, and height, the former athletes were found to have higher BMD at all sites at every follow-up visit except the last one, when compared with controls (P < 0.05). The active athletes were found to have significantly higher BMD at all measured locations when compared with controls throughout the entire study (P < 0.05). From the first to the final follow-up visit, the former athletes were found to have lost more femoral neck BMD than both the active athletes (mean difference, 0.12 g/cm(2); P = 0.003) and controls (mean difference 0.08 g/cm(2); P = 0.02). CONCLUSION This study suggests that BMD constantly adapts to the present physical activity levels in young men. Thus, increased BMD due to previous high physical activity may not prevent osteoporosis in later years.

Reduced physical activity corresponds with greater bone loss at the trabecular than the cortical bone sites in men

Previous research has been inconclusive as to whether high peak bone mineral density (BMD, g/cm(2)) resulting from previous physical activity is retained with reduced activity later in life. The aim of this 12-year longitudinal study was to investigate the association between BMD loss and reduced physical activity (h/wk) at trabecular and cortical bone sites in men. Three groups with a mean age of 17 years at baseline were investigated: i) 51 athletes who discontinued their active careers during the follow-up period (former athletes), ii) 16 athletes who were active throughout the follow-up period (active athletes), and iii) 25 controls. BMD loss at the hip, spine, and pelvis (mainly trabecular bone) was compared to BMD loss at femur, humerus, and legs (mainly cortical bone) during a 12-year follow-up period. Across the total follow-up period in the total cohort, reduced physical activity was more strongly associated with changes at trabecular BMD sites, i.e. hip, spine, and pelvis (B=0.008-0.005 g/cm(2) per weekly hour physical activity (h), p<0.001), than at cortical bone sites, i.e. humerus, legs (B=0.002-0.003 g/cm(2)/h, p<0.05), and femur (p>0.05). At the final follow-up, former athletes showed higher BMD than controls only at the cortical bone sites of the humerus, legs, and femur (difference 0.05-0.10 g/cm(2), p<0.05). In conclusion, this study indicates that predominantly trabecular bone is lost with reduced physical activity levels in young men. Benefits were still evident at the more cortical sites eight years after the discontinuation of an active sports career.

Effects of badminton and ice hockey on bone mass in young males: A 12-year follow-up

The purpose of the present study was to investigate the influence of different types of weight bearing physical activity on bone mineral density (BMD, g/cm(2)) and evaluate any residual benefits after the active sports career. Beginning at 17 years of age, BMD was measured 5 times, during 12 years, in 19 badminton players, 48 ice hockey players, and 25 controls. During the active career, badminton players gained significantly more BMD compared to ice hockey players at all sites: in their femoral neck (mean difference (Delta) 0.06 g/cm(2), p=0.04), humerus (Delta 0.06 g/cm(2), p=0.01), lumbar spine (Delta 0.08 g/cm(2), p=0.01), and their legs (Delta 0.05 g/cm(2), p=0.003), after adjusting for age at baseline, changes in weight, height, and active years. BMD gains in badminton players were higher also compared to in controls at all sites (Delta 0.06-0.17 g/cm(2), p<0.01 for all). Eleven badminton players and 37 ice hockey players stopped their active career a mean of 6 years before the final follow-up. Both these groups lost significantly more BMD at the femoral neck and lumbar spine compared to the control group (Delta 0.05-0.12 g/cm(2), p<0.05 for all). At the final follow-up, badminton players had significantly higher BMD of the femoral neck, humerus, lumbar spine, and legs (Delta 0.08-0.20 g/cm(2), p<0.01 for all) than both ice hockey players and controls. In summary, the present study may suggest that badminton is a more osteogenic sport compared to ice hockey. The BMD benefits from previous training were partially sustained with reduced activity.

The Effect of Physical Activity on Bone Accrual, Osteoporosis and Fracture Prevention

Background: Physical activity has been recommended for the prevention and even treatment of osteoporosis because it potentially can increase bone mass and strength during childhood and adolescence and reduce the risk of falling in older populations. However, few reports have systematically investigated the effect of physical activity on bone in men and women of different ages. Purpose: The goal of this study was to review the literature relating to the effect of physical activity on bone mineral density in men and women of various ages. Method: This review systematically evaluates the evidence for the effect of physical activity on bone mineral density. Cochrane and Medline databases were searched for relevant articles, and the selected articles were evaluated. Results: The review found evidence to support the effectiveness of weight bearing physical activity on bone accrual during childhood and adolescence. The effect of weight bearing physical activity was site-specific. In contrast, the role of physical activity in adulthood is primarily geared toward maintaining bone mineral density. The evidence for a protective effect of physical activity on bone is not as solid as that for younger individuals. Conclusions: The effect of weight bearing physical activity is seen in sites that are exposed to loading. There also seems to be a continuous adaptive response in bone to loading. Additional randomized, controlled studies are needed to evaluate the effect of physical activity in the elderly.

Science of floorball: a systematic review.

Background The purpose of this study was to comprehensively review the scientific research on floorball at the competitive and recreational levels according to field of study. Methods Full articles containing original data on floorball that had been published in English in peer-reviewed journals were considered for inclusion. Results Of 75 articles screened, 19 were included in this systematic review. One article each was identified in the fields of sports management and sports psychology, and the remaining 17 articles were in the field of sports medicine. Injury epidemiology in floorball players was the most thoroughly examined topic of research. To date, no research has been performed on the incidence of floorball-related injury, or any aspect of the sport, in children and adolescents. Conclusion Collaborative research among sports science disciplines is needed to identify strategies to reduce the incidence of injury and enhance the performance of licensed floorball players. Despite the increasing popularity of floorball in recent years, surprisingly little research has examined this sport.

Association between Self-Perceived Health, Physical Activity, and BMD in Aging Men and Women

Background: Osteoporosis is a skeletal disease that affects one out of every two women and one out of every five men. The clinical significance of this disease lies in the associated increased risk ...