The Loess Regression Relationship Between Age and BMI for both Sydney World Masters Games Athletes and the Australian National Population
Thousands of masters athletes participate
quadrennially in the World Masters Games (WMG), yet this cohort
of athletes remains proportionately under-investigated. Due to a
growing global obesity pandemic in context of benefits of physical
activity across the lifespan, the BMI trends for this unique population
was of particular interest. The nexus between health, physical
activity and aging is complex and has raised much interest in recent
times due to the realization that a multifaceted approach is necessary
in order to counteract the obesity pandemic. By investigating age
based trends within a population adhering to competitive sport at
older ages, further insight might be gleaned to assist in understanding
one of many factors influencing this relationship.BMI was derived
using data gathered on a total of 6,071 masters athletes (51.9% male,
48.1% female) aged 25 to 91 years ( =51.5, s =±9.7), competing at
the Sydney World Masters Games (2009). Using linear and loess
regression it was demonstrated that the usual tendency for prevalence
of higher BMI increasing with age was reversed in the sample. This
trend in reversal was repeated for both male and female only sub-sets
of the sample participants, indicating the possibility of improved
prevalence of BMI with increasing age for both the sample as a
whole and these individual sub-groups.This evidence of improved
classification in one index of health (reduced BMI) for masters
athletes (when compared to the general population) implies there are
either improved levels of this index of health with aging due to
adherence to sport or possibly the reduced BMI is advantageous and
contributes to this cohort adhering (or being attracted) to masters
sport at older ages.
 Sydney 2009 World Masters Games Committee. (2009). Sydney 2009
World Masters Games Final Report.
 Sawyer, K., & Sceppa, C. (2010). Cardiovascular disease - Review-
Impact of aerobic physical activity on cardiovascular and
noncardiovascular outcomes: is anyone too old to exercise? Aging
Health, 6(2), 251-260.
 Williamson, J., & Pahor, M. (2010). Evidence Regarding the Benefits of
Physical Exercise Archives of Internal Medicine, 170(2), 124-125.
 Ryan, A. (2010). Review exercise in aging: it-s important role in
mortality, obesity and insulin resistance. Aging Health, 6(5), 551-563.
 Kenyon, C. (2010). The genetics of aging. Nature 464, 504-512.
 King, A., & Guralnik, J. (2010). Maximizing the potential of an aging
population. The Journal of the American Medical Association, 304(17)
 Doherty, T. (2003). Aging and sarcopenia. Journal of Applied
Physiology, 95(4) 1717-1727.
 Garabed, E. (2008). Adolphe Quetelet (1796-1874)ÔÇöthe average man
and indices of obesity. Nephrology Dialysis Transplantation, 23, 47-51
 Walsh, J., Climstein, M., Heazlewood, I.T., Burke, S., Kettunen, J.,
Adams, K., & DeBeliso, M. (2011). Body mass index for Australian
athletes participating at the World Masters Games. World Academy of
Science Engineering and Technology (WASET) Journal, 7(77), 1119-
 World Health Organisation (2002). The world health report 2002 -
Reducing Risks, Promoting Healthy Life, 4, 60.
 Australian Bureau of Statistics (2010). National health survey: summary
of results, 2007-2008 (Reissue).
 Sui, X., LaMonte, M., Laditka, J., Hardin, J., Chase, N., Hooker, S. &
Blair, N. (2007). Cardiorespiratory fitness and adiposity as mortality
predictors in older adults. Journal of the American Medical Association,
 Australian Institute of Health and Welfare 2008. Australia-s health 2008.
Cat. no. AUS 99. Canberra: Australian Institute of Health and Welfare
 Begg, S., Vos, T., Barker, B., Stevenson, C., Stanley, L., & Lopez, A.
(2007). The burden of disease and injury in Australia 2003. PHE 82.
Canberra: Australian Institute of Health and Welfare.
 Cleveland, W. & Loader, C. (1995). Smoothing by local regression:
Principles and Methods (Technical report). Murray Hill, NJ: A&T Bell