Performance trade-offs and individual quality in decathletes

Abstract

Many constraints of organismal design at the cell and organ level, including muscle fiber types, musculoskeletal gearing and controlsurface geometry, are believed to cause performance trade-offs at the whole-organism level. Contrary to this expectation, positive correlations between diverse athletic performances are frequently found in vertebrates. Recently, it has been proposed that trade-offs between athletic performances in humans are masked by variation in individual quality and that underlying trade-offs are revealed by adjusting the correlations to 'control' quality. We argue that quality is made up of both intrinsic components, due to the causal mapping between morpho-physiological traits and performance, and extrinsic components, due to variation in training intensity, diet and pathogens. Only the extrinsic component should be controlled. We also show that previous methods to estimate 'quality-free' correlations perform poorly. We show that Wright's factor analysis recovers the correct quality-free correlation matrix and use this method to estimate quality-free correlations among the 10 events of the decathlon using a dataset of male college athletes. We found positive correlations between all decathlon events, which supports an axis that segregates 'good athletes' from 'bad athletes'. Estimates of quality-free correlations are mostly very small (<0.1), suggesting large, quality-free independence between events. Because quality must include both intrinsic and extrinsic components, the physiological significance of these adjusted correlations remains obscure. Regardless, the underlying architecture of the functional systems and the physiological explanation of both the un-adjusted and adjusted correlations remain to be discovered.

Performance trade-offs and ageing in the ‘world's greatest athletes’

“…It has been suggested that performance trade-offs emerge as expected after statistically adjusting for among-individual variation in 'quality' [15,19]. However, recent work has shown that performance trade-offs are not always detected when 'quality'-in whatever ambiguous form it can take-is accounted for [16]. Here, we showed the severity of the bias in correlations based on personal bests values [23,38], which calls into question the relevance of the debate on the need to control for 'quality' [15,16,19].…”

“…The difference in figure 1a versus figure 1b shows the extent of the bias introduced by using personal best values. Note, however, that there is a positive correlation between n trial and the athletes average score (decathlon: r 634 ¼ 0.68; heptathlon: r 731 ¼ 0.67), such that controlling for n trial may also partially control for 'quality' [15,16]. In decathletes, all r ind .…”

“…Yet, like many studies on non-human animals [11][12][13][14], performance trade-offs have proven hard to detect in decathletes. Indeed, past studies report mostly positive or non-significant correlations among performances in the 10 events of the decathlon [15][16][17][18]. How can we explain these counterintuitive results [15][16][17][18]?…”

From operculum and body tail movements to different coupling of physical activity and respiratory frequency in farmed gilthead sea bream and European sea bass. Insights on aquaculture biosensing

“…Traits related to locomotor performance and metabolism are subjected to natural selection as they are often coupled with important behaviors, such as predator evasion, prey capture, reproduction, migration and dominance (Boel et al, 2014;Seebacher et al, 2013;Walker et al, 2005;Wilson et al, 2013). Moreover, an organism may specialize in one trial at the cost of the other, in which case the trade-off between antagonistic traits evolve causing phenotypic differentiation (Herrel et al, 2009;Heitz, 2014;Walker and Caddigan, 2015;Zhang et al, 2017). In fish, a good example is the trade-off between endurance capacity and sprint speed (Langerhans, 2009;Oufiero et al, 2011), and fish species with "active" lifestyle often have higher rates of dispersal in comparison to sedentary species (Réale et al, 2010;Careau and Garland, 2012).…”

Partitioning the metabolic scope: the importance of anaerobic metabolism and implications for the oxygen- and capacity-limited thermal tolerance (OCLTT) hypothesis

“…Performance trade-offs often play important roles in relation to phenotypic variation found between individuals ( Oufiero et al , 2011 ; Seebacher and Walter, 2012 ; Svendsen et al , 2015 ) and may take place when two antagonistic traits cannot be optimized simultaneously because of conflicting demands on the same capacity ( Priede, 1985 ; Roff and Fairbairn, 2007 ; Svendsen et al , 2015 ), such as the oxygen budget ( Farrell, 2007 ; Altimiras et al , 2008 ). This implies that excellence in one trait comes at the cost of performance in a different trait ( Vanhooydonck et al , 2014 ; Walker and Caddigan, 2015 ), which is classically exemplified by the conflicting relationship between sprinters and endurance athletes ( Reidy et al , 2000 ; Van Damme et al , 2002 ; Marras et al , 2013 ). To date, evidence of the corresponding locomotory trade-off in fishes remains inconclusive, with some studies finding support ( Reidy et al , 2000 ; Ojanguren and Braña, 2003 ; Langerhans, 2009 ; Oufiero et al , 2011 ; Ellerby and Gerry, 2011 ; Yan et al, 2012) , whereas others have not ( Claireaux et al , 2007 ; Oufiero and Garland, 2009 ; Seebacher and Walter, 2012 ; Marras et al , 2013 ).…”