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Can economic principles inform player management?
Cost-benefit analysis is a term often heard in the world of economics. Businesses seek to maximise profits by comparing the costs and benefits of a proposed venture. Cost-benefit analysis is a valuable analytical technique that can also inform decisions in the clinical sports medicine setting.1 Specifically, cost-benefit analysis provides a useful framework to quantify the relationship between the ‘benefit’ of improved performance from a given training load, and the associated ‘cost’ of increased injury risk.
‘I Want You to Push Them to Breaking Point—Just Don't Break Them!’
Elite sport provides a starting point for any discussion relating to the costs and benefits of high workloads. Elite players are often exposed to year-long training and high match frequencies, with periods of a congested calendar, which sometimes increases injury risk.2–4 These competitive demands place physical stress on players, requiring well-developed physical qualities to avoid injury and illness, and to perform optimally. While proposing an economic analysis for evaluating costs and benefits in sports medicine may sound surprising, it is a process managers constantly (and intuitively) undergo on a daily basis. During training, managers/coaches may instruct sport science staff to introduce high training loads to promote maximal fitness gains (benefit) and develop ‘mental toughness’, but not to pass the ‘breaking point’ (cost). They want workloads prescribed with the largest benefit while maintaining the smallest cost.
Cost-benefit analysis can help decision-making in elite sport
The challenge for coaches/managers and clinicians (a term we use that includes strength and conditioning coaches/sport scientists) is to provide an adequate training stimulus to induce adaptations in physical qualities and performance, without unduly increasing the costs—increased injury risks.5 Both under-training and over-training substantially increase injury risk.6 ,7 Inappropriate training can also adversely impact performance; under-training results in an athlete being underprepared for competition, while over-training can lead to prolonged fatigue, depression, signs and symptoms of stress, lack of vigour and, of course, poor performance.8
Practical application: cost-benefit analysis in sport
How can cost-benefit analysis be applied in an elite sporting context (figure 1)? Using total distance and high-speed distance covered as our training load measures, we represent cost through injuries sustained, and the benefit through estimated maximal aerobic speed distance (ie, physical fitness). These data illustrate the expected cost and benefit associated with a given training load during a single preseason period, with the ideal outcome illustrated as low cost-benefit ratio.
For sport medicine staff, there are three major challenges to prescribing loads that optimise the cost-benefit ratio:
Multifactorial nature of costs and benefits
There are numerous factors to account for in determining the costs (eg, fatigue, risk of injury during activity and risk of subsequent injury) and benefits (eg, improved aerobic capacity, skill and performance) of a given workload. At times, certain factors may be deemed more crucial (eg, minimising injury risk during playoffs or maximising aerobic capacity during the preseason). Understanding the way training loads impact each of these parameters and the relative importance of each at specific times can encourage evidence-based decision-making.
Much like the stock market, the optimal cost-benefit ratio is a moving target. For example, a high training load may carry the cost of a very high-injury risk if it constitutes a ‘spike’ in workload (ie, a high acute:chronic workload ratio), while that same high training load can decrease injury risk if comparable with chronic workload (ie, the load-injury prevention paradox).7
Ideally, individual responses should be used in the cost-benefit framework. For instance, by identifying the players who respond/do not respond to high-intensity (or low-intensity) training, individual loads may be adapted to maximise benefits.
‘Undercooked’ or ‘Overdone’—balancing the risk and reward of training
Despite the complexity of analysing injury risk and performance improvements for various training loads, much progress has been made. Traditionally, it has been a purely philosophical question of how much injury risk a player and team are willing to bear in exchange for performance benefits. Conservative coaches tried avoiding injuries, potentially sacrificing performance in the process. Other coaches pushed players harder, accepting more frequent injuries as a consequence of higher training loads. However, as we continue to better understand how training loads predict injuries, and how individual responses to training vary, we combine philosophy with science to train smarter and harder. At least theoretically, there is a point on the training load equilibrium at which the trade-off between performance and injury risk results in the greatest overall benefit for teams. This point would involve minimal injury risk while simultaneously ensuring players are ready for the performance requirements of the game—the ideal cost-benefit ratio.
Contributors TJG developed the initial concept for the paper. HTG and TJG wrote the initial draft of the paper. JW provided feedback on several versions of the paper. All the authors share equal responsibility for the content of the paper.
Competing interests None declared.
Provenance and peer review Not commissioned; externally peer reviewed.