Physical activity (PA) is thought to play an important role in preventing bone loss and osteoporosis in older people. However, the type of activity that is most effective in this regard remains unclear. Objectively measured PA using accelerometers is an accurate method for studying relationships between PA and bone and other outcomes. We recently used this approach in the Avon Longitudinal Study of Parents and Children (ALSPAC) to examine relationships between levels of vertical impacts associated with PA and hip bone mineral density (BMD). Interestingly, vertical impacts >4g, though rare, largely accounted for the relationship between habitual levels of PA and BMD in adolescents. However, in a subsequent pilot study where we used the same method to record PA levels in older people, no >4g impacts were observed. Therefore, to the extent that vertical impacts need to exceed a certain threshold in order to be bone protective, such a threshold is likely to be considerably lower in older people as compared with adolescents. Further studies aimed at identifying such a threshold in older people are planned, to provide a basis for selecting exercise regimes in older people which are most likely to be bone protective.
Keywords: impact loading, bone, physical activity, BMD, exercise
Citation: Tobias JH, Gould V, Brunton L, Deere K, Rittweger J, Lipperts M and Grimm B (2014) Physical activity and bone: may the force be with you. Front. Endocrinol. 5:20. doi: 10.3389/fendo.2014.00020
Received: 06 January 2014; Paper pending published: 22 January 2014;
Accepted: 13 February 2014; Published online: 03 March 2014.
Edited by:Mark Stuart Cooper, University of Birmingham, UK
Reviewed by:Mark Stuart Cooper, University of Birmingham, UK
Copyright: © 2014 Tobias, Gould, Brunton, Deere, Rittweger, Lipperts and Grimm. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) or licensor are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.
*Correspondence: Jonathan H. Tobias, Musculoskeletal Research Unit, University of Bristol School of Clinical Sciences, Avon Orthopaedic Centre, Southmead Hospital, Southmead Road, Bristol BS10 5NB, UK e-mail: firstname.lastname@example.org