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.

Authors:

• Joe Walsh
• Mike Climstein
• Ian Timothy Heazlewood
• Stephen Burke
• Jyrki Kettunen
• Kent Adams
• Mark DeBeliso

Keywords:

• Aging
• masters athlete
• Quetelet Index
• sport

References:

[1] Sydney 2009 World Masters Games Committee. (2009). Sydney 2009
World Masters Games Final Report.
[2] 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.
[3] Williamson, J., & Pahor, M. (2010). Evidence Regarding the Benefits of
Physical Exercise Archives of Internal Medicine, 170(2), 124-125.
[4] Ryan, A. (2010). Review exercise in aging: it-s important role in
mortality, obesity and insulin resistance. Aging Health, 6(5), 551-563.
[5] Kenyon, C. (2010). The genetics of aging. Nature 464, 504-512.
[6] King, A., & Guralnik, J. (2010). Maximizing the potential of an aging
population. The Journal of the American Medical Association, 304(17)
1954-1955.
[7] Doherty, T. (2003). Aging and sarcopenia. Journal of Applied
Physiology, 95(4) 1717-1727.
[8] Garabed, E. (2008). Adolphe Quetelet (1796-1874)ÔÇöthe average man
and indices of obesity. Nephrology Dialysis Transplantation, 23, 47-51
[9] 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-
1123.
[10] World Health Organisation (2002). The world health report 2002 -
Reducing Risks, Promoting Healthy Life, 4, 60.
[11] Australian Bureau of Statistics (2010). National health survey: summary
of results, 2007-2008 (Reissue).
[12] 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,
298(21), 2507-2516.
[13] Australian Institute of Health and Welfare 2008. Australia-s health 2008.
Cat. no. AUS 99. Canberra: Australian Institute of Health and Welfare
[14] 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.
[15] Cleveland, W. & Loader, C. (1995). Smoothing by local regression:
Principles and Methods (Technical report). Murray Hill, NJ: A&T Bell
Laboratories.