Research article
Levels of Physical Activity That Predict Optimal Bone Mass in Adolescents: The HELENA Study

https://doi.org/10.1016/j.amepre.2011.03.001Get rights and content

Background

Physical activity is necessary for bone mass development in adolescence. There are few studies quantifying the associations between physical activity and bone mass in adolescents.

Purpose

To assess the relationship between moderate-to-vigorous physical activity (MVPA) and vigorous physical activity (VPA) and bone mass in adolescents.

Methods

Bone mass was measured by dual-energy X-ray absorptiometry and physical activity by accelerometers in 380 healthy Spanish adolescents (189 boys, aged 12.5–17.5 years) from the HELENA–CSS (2006–2007). Subjects were classified according to the recommended amount of MVPA (<60 minutes or ≥60 minutes of MVPA/day). Receiver operating characteristic curve analysis was applied to calculate the relationship between physical activity and bone mass.

Results

Less than 41 and 45 minutes of MVPA/day are associated with reduced bone mass at the trochanter and femoral neck. More than 78 minutes of MVPA/day is associated with increased bone mineral density (BMD) at the femoral neck. Regarding VPA, more than 28 minutes/day for the hip and intertrochanter and more than 32 minutes/day for the femoral neck are associated with increased BMD.

Conclusions

The recommended amount of physical activity (minutes/day) seems insufficient to guarantee increased bone mass. With some minutes of VPA/day, bone adaptations could be obtained at different bone sites.

Introduction

Osteoporosis is a common health problem. In fact, about 2.7 million of European men and women suffer an osteoporotic fracture every year,1 which is associated with high morbidity and mortality rates.2 The economic burden of osteoporosis in Europe is higher than any kind of cancer (except lung cancer) or chronic cardiorespiratory diseases2, 3 and represents a direct annual cost of $48 billion.1 To improve the outcome for osteoporosis sufferers, prevention remains the most important action in public health.

Acquiring a high bone mass during childhood and adolescence is a key determinant of adult skeletal health4 and it may decrease the risk of osteoporotic fractures by 50%.5, 6 Exercise has been associated with bone accretion showing an important osteogenic effect, mainly when high-impact and weight-bearing physical activity occur.7 Muscle mass is also a determinant of bone development.8 Intensive physical activity, for example, participation in sport, is associated with increased development of muscle mass during growth.8, 9 Therefore, exercise may indirectly increase bone mass by increasing lean mass. In terms of bone health, it is not only the amount of physical activity that is important but also the type of physical activity.

Physical Activity Guidelines for children and adolescents recommend (1) that young people should accumulate at least 60 minutes (up to several hours) of moderate-to-vigorous physical activity (MVPA) per day; and (2) at least 3 days per week this should include activities to improve bone health and muscle strength.10 To date, most studies assessed physical activity subjectively (i.e., using questionnaires), even when it has been shown that participants could under- or over-report physical activity in this population group,11, 12 which is an important issue. However, few studies have evaluated the association of objectively assessed physical activity and bone mass in adolescents. One study13 showed a positive association between total hip BMC and the time spent (minutes/day) in vigorous and total physical activity in Swiss boys aged 6–13 years; although another study14 of boys and girls aged 11 years from the United Kingdom showed a positive association between lower limbs' BMD and the time spent (minutes/day) in MVPA.

It is relevant to know whether current physical activity recommendations for adolescents are sufficient for healthy bone mass development, and this has not been studied yet. Therefore, the aim of this report is to analyze the relationships between MVPA and vigorous physical activity (VPA) and bone mass in different regions (whole body, pelvis, lumbar spine, and total hip) and subregions (trochanter, intertrochanter, and femoral neck).

Section snippets

Subjects

The HELENA (Healthy Lifestyle in Europe by Nutrition in Adolescence) project is funded by the European Union and includes a cross-sectional multicenter study (HELENA–CSS) that was performed in adolescents aged 12.5–17.5 years from ten European cities15 in 2006–2007. The general characteristics of the HELENA–CSS have been described in detail elsewhere.16 In this report, the only sample included is from the only city (Zaragoza) where bone mineral content (BMC) and bone mineral density (BMD) were

Results

Table 1 shows descriptive characteristics (M±SD) of the study sample. For boys, active adolescents had a significantly higher calcium intake and calcium intake/lean mass ratio and they spent more minutes on MVPA and VPA than non-active ones (all p<0.05). For girls, active adolescents were significantly taller and spent more minutes on MVPA and VPA, and they had significantly lower body mass and BMI than non-active ones (all p<0.05). Except for lumbar spine BMD in girls (p<0.05; Table 2),

Discussion

The findings of the present study indicate that (1) there are no BMC and BMD differences in most body regions among adolescents regardless of whether they meet the current physical activity recommendations or not, and (2) specific thresholds of physical activity are associated with reduced or increased bone mass groups.

This is the first study analyzing, in adolescents, whether meeting the current physical activity recommendations (60 minutes/day of MVPA) or not has any effect on BMC and BMD at

Conclusion

The recommended levels of physical activity seem to be insufficient stimulus to guarantee increased bone mass. With some minutes/day of VPA, bone adaptations could be obtained at the hip. Specifically, BMD adaptations are obtained with just 32 minutes/day of VPA at the femoral neck, which is of great importance because of its clinical relevance to osteoporosis. It could be of interest if future studies aim to measure not only the amount of physical activity but also the type and, therefore, get

References (37)

  • G. Vicente-Rodriguez et al.

    High femoral bone mineral density accretion in prepubertal soccer players

    Med Sci Sports Exerc

    (2004)
  • G. Vicente-Rodriguez et al.

    Artistic versus rhythmic gymnastics: effects on bone and muscle mass in young girls

    Int J Sports Med

    (2007)
  • Key guidelines for children and adolescents

  • M. Hagstromer et al.

    Concurrent validity of a modified version of the International Physical Activity Questionnaire (IPAQ-A) in European adolescents: the HELENA Study

    Int J Obes (Lond)

    (2008)
  • D.R. Bassett

    Validity and reliability issues in objective monitoring of physical activity

    Res Q Exerc Sport

    (2000)
  • S. Kriemler et al.

    Weight-bearing bones are more sensitive to physical exercise in boys than in girls during pre- and early puberty: a cross-sectional study

    Osteoporos Int

    (2008)
  • J.H. Tobias et al.

    Habitual levels of physical activity influence bone mass in 11-year-old children from the United Kingdom: findings from a large population-based cohort

    J Bone Miner Res

    (2007)
  • L.A. Moreno et al.

    Assessing, understanding and modifying nutritional status, eating habits and physical activity in European adolescents: the HELENA (Healthy Lifestyle in Europe by Nutrition in Adolescence) Study

    Public Health Nutr

    (2008)
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