Re: Mortality in former Olympic athletes: retrospective cohort analysis
We read with interest the recent paper by Zwiers et al (1). Rugby was alluded to as one of the disciplines which appear to predispose top athletes to a higher mortality due to repeated body collisions and high physical contact. Recent developments in rugby have seen augmented player size, shuddering hits and a corresponding increase in injury rate (2, 3).
We have recently completed a study exploring the physical characteristics of 95 modern-day professional rugby union and rugby league players (age 25.9±4.3 years) of the highest standard in the UK. These sportsmen have physiques unlike any other. At first glance, body mass index (29.5±2.9 kg.m-2) would suggest overweight or obesity, but on examination of DXA reports, these men have low levels of body fat (%BF: 17.7±4.1), substantial lean mass (78.1±8.1 kg), and their bones are far denser than average (total body Z-score: 3.6±1.2). The question we ask is why would these men be at risk of greater mortality due to repeated collisions? Doesn’t the musculoskeletal system respond and adapt to the loads it is exposed to? This is all highly documented in Frost’s Mechanostat seminal model (4) and has formed the basis of countless exercise intervention studies. Perhaps rugby-related trauma regularly exceeds the operational strain threshold of the body and adverse effects on biological and physiological systems have not yet been identified. Could aging be accelerated? Cervical spine degeneration and osteoarthritis is frequently reported in professional rugby players (5, 6).
Zwiers and colleagues’ important findings should provide the impetus for research into the hidden risk factors for increased mortality risk in this unique population. As the group rightly points out, professionalism in sport has resulted in a substantially greater physicality than the early 1900’s. This is particularly true for both codes of rugby, with professional players often referred to as ‘superhuman’, and a media emphasis increasingly placed on the size of the players and the impacts of the ‘hits’. Whilst gladiatorial and entertaining to watch, these athletes are not machines, nor are superhuman. The risk factors for their apparent high mortality risk warrant timely investigation.
1. Zwiers R, Zantvoord FWA, Engelaer FM, et al. Mortality in former Olympic athletes: retrospective cohort analysis. BMJ 2012. 345:e7456 doi: 10.1136/bmj.e7456
2. Kaplan KM, Goodwillie A, Strauss EJ, Rosen JE. Rugby injuries: A review of concepts and current literature. Bull NYU Hosp Joint Dis 2008. 66:2:86-93
3. English rugby premiership training and injury audit steering group. England rugby premiership training and injury audit 2010-2011 Rugby Football Union 2011
4. Frost HM. Bone ‘mass’ and the ‘mechanostat’: A proposal. The Anatom Rec 219:1:1-9
5. Castinel BH, Adam P, Milburn PD et al. Epidemiology of cervical spine abnormalities in asymptomatic adult professional rugby union players using static and dynamic MRI protocols 2002-2006. BJSM 2010. 44:194-199
6. Molloy MG, Molloy CB. Contact sport and osteoarthritis. BJSM 2011. 45:275-277