Does individual quality mask the detection of performance trade-offs? A test using analyses of human physical performance

Abstract

Why are performance trade-offs so rarely detected in animals when their underlying physiological basis seems so intuitive? One possibility is that individual variation in health, fitness, nutrition, development or genetics, or 'individual quality', makes some individuals better or worse performers across all motor tasks. If this is the case, then correcting for individual quality should reveal functional trade-offs that might otherwise be overlooked. We tested this idea by exploring trade-offs in maximum physical performance and motor skill function in semiprofessional soccer players. We assessed individual performance across five maximum 'athletic' tasks providing independent measures of power, stamina and speed, as well as five soccer-specific 'motor skill' tasks providing independent measures of foot control. We expected to find functional trade-offs between pairs of traits (e.g. endurance versus power/speed tasks or specialist-generalist performance) -but only after correcting for individual quality. Analyses of standardised raw data found positive associations among several pairs of traits, but no evidence of performance trade-offs. Indeed, peak performance across a single athletic task (degree of specialisation) was positively associated with performance averaged across all other athletic tasks (generalist). However, after accounting for an individual's overall quality, several functional trade-offs became evident. Within our qualitycorrected data, 1500 m-speed (endurance) was negatively associated with squat time (power), jump distance (power) and agility speedreflecting the expected speed-endurance trade-off; and degree of specialisation was negatively associated with average performance across tasks. Taken together, our data support the idea that individual variation in general quality can mask the detection of performance trade-offs at the whole-animal level. These results highlight the possibility that studies may spuriously conclude certain functional tradeoffs are unimportant or non-existent when analyses that account for variation in general quality may reveal their cryptic presence.

Skill not athleticism predicts individual variation in match performance of soccer players

“…Such topics include deception [32], senescence [33] and functional trade-offs [29,30]. Similarly, approaches to data analysis used by evolutionary biologists to study adaptation, multivariate trait evolution and adaptive landscapes can also contribute to advances in sports science.…”

Sprint sensitivity and locomotor trade-offs in green anole (Anolis carolinensis) lizards

“…Conversely, long relative limbs are favored in arboreal lizard species that occupy broad perches or terrestrial lizard species that live in open habitats with few obstacles (Losos and Sinervo, 1989;Bauwens et al, 1995). If there is one preferred microhabitat on which locomotion is maximized, as in Caribbean Anolis lizards (reviewed in Losos, 2009), then selection will favor performance specialization, and locomotor trade-offs may result across species (Vanhooydonck et al, 2001;Angilletta et al, 2003;Wilson et al, 2014). However, if many substrates are frequently used, then the phenotype may be a compromise, because fitness may depend on sufficient locomotion on a variety of substrates.…”

Effects of added drag on cetaceans : fishing gear entanglement and external tag attachment

“…Gear drag contributes to the immediate sublethal effects of entanglement: direct injury and physiological disturbances, such as stress and metabolic responses (Wilson et al, 2014a).…”

“…Entanglement in fishing gear remains a significant issue for marine animal species worldwide (Hofmeyr et al, 2006;Moore et al, 2009;van der Hoop et al, 2013a).While mortality is the simplest indicator of a negative entanglement outcome, the subtler sublethal effects in the form of stress response, metabolic disturbance, and behavioral impairment can and should be considered (Wilson et al, 2014a), especially in cetaceans, where mortality detection probabilities are remarkably low (Williams et al, 2011;Wells et al, 2014). The amount of drag imposed from entangling gear is a factor in defining entanglement JvdH proposed the project; DPN and MJM performed fieldwork; DPN, MT, MJM guided the analysis; JvdH processed and analyzed data; JvdH wrote the paper; JvdH, DPN, MJM, MT contributed to the manuscript.…”

“…Entrapment and injury in gear are most common for porpoise and dolphin species (Kuiken et al, 1994;; even with subsequent release, these types of interactions can result in sub-lethal impacts (Wilson et al, 2014a). Individuals are found with gear still attached, where gear has mostly been identified as monofilament and crab float lines (Wells et al, 1998;NOAA, 2008;Wells et al, 2008;Barco and Moore, 2010;.…”