The search for an early biomarker of exercise-induced performance decrement related to muscle damage is an ongoing topic of interest by exercise physiologists, and cell-free DNA (cfDNA) in the plasma is one of the most investigated recently. Small quantities of cfDNA are found both in healthy
Michely V. Andreatta, Victor M. Curty, João Victor S. Coutinho, Miguel Ângelo A. Santos, Paula F. Vassallo, Nuno F. de Sousa and Valério G. Barauna
Mark Evans, Peter Tierney, Nicola Gray, Greg Hawe, Maria Macken and Brendan Egan
An important determinant of success in team sports is repeated sprint performance (RSP; Girard et al., 2011 ). RSP involves maximal or near-maximal short-duration sprints repeated in succession with brief recovery periods. Fatigue manifests as a sprint performance decrement (S dec ; %) over time
Anne Delextrat, Sinead Mackessy, Luis Arceo-Rendon, Aaron Scanlan, Roger Ramsbottom and Julio Calleja-Gonzalez
jump mat (Ergojump; Globus Inc., Treviso, Italy) was used to record jump height (cm) for every circuit. The jump performed was a countermovement jump with the hands on hips ( Buchheit, 2010 ). Finally, sprint and jump performance decrements (PDs) were calculated using the following equations ( Glaister
André Klostermann, Ralf Kredel and Ernst-Joachim Hossner
To date, despite a large body of evidence in favor of the advantage of an effect-related focus of attention compared with a movement-related focus of attention in motor control and learning, the role of vision in this context remains unclear. Therefore, in a golf-putting study, the relation between attentional focus and gaze behavior (in particular, quiet eye, or QE) was investigated. First, the advantage of an effect-related focus, as well as of a long QE duration, could be replicated. Furthermore, in the online-demanding task of golf putting, high performance was associated with later QE offsets. Most decisively, an interaction between attentional focus and gaze behavior was revealed in such a way that the efficiency of the QE selectively manifested under movement-related focus instructions. As these findings suggest neither additive effects nor a causal chain, an alternative hypothesis is introduced explaining positive QE effects by the inhibition of not-to-be parameterized movement variants.
Manuel D. Quinones and Peter W.R. Lemon
Hydrothermally modified non-genetically modified organisms corn starch (HMS) ingestion may enhance endurance exercise performance via sparing carbohydrate oxidation. To determine whether similar effects occur with high-intensity intermittent exercise, we investigated the effects of HMS ingestion prior to and at halftime on soccer skill performance and repeated sprint ability during the later stages of a simulated soccer match. In total, 11 male university varsity soccer players (height = 177.7 ± 6.8 cm, body mass = 77.3 ± 7.9 kg, age = 22 ± 3 years, body fat = 12.8 ± 4.9%, and maximal oxygen uptake = 57.1 ± 3.9 ml·kg BM−1·min−1) completed the match with HMS (8% carbohydrate containing a total of 0.7 g·kg BM−1·hr−1; 2.8 kcal·kg BM−1·hr−1) or isoenergetic dextrose. Blood glucose was lower (p < .001) with HMS at 15 min (5.3 vs. 7.7 mmol/L) and 30 min (5.6 vs. 8.3 mmol/L) following ingestion, there were no treatment differences in blood lactate, and the respiratory exchange ratio was lower with HMS at 15 min (0.84 vs. 0.86, p = .003); 30 min (0.83 vs. 0.85, p = .004); and 45 min (0.83 vs. 0.85, p = .007) of the first half. Repeated sprint performance was similar for both treatments (p > .05). Soccer dribbling time was slower with isoenergetic dextrose versus baseline (15.63 vs. 14.43 s, p < .05) but not so with HMS (15.04 vs. 14.43 s, p > .05). Furthermore, during the passing test, penalty time was reduced (4.27 vs. 7.73 s, p = .004) with HMS. During situations where glycogen availability is expected to become limiting, HMS ingestion prematch and at halftime could attenuate the decline in skill performance often seen late in contests.
Alexander S.D. Gamble, Jessica L. Bigg, Tyler F. Vermeulen, Stephanie M. Boville, Greg S. Eskedjian, Sebastian Jannas-Vela, Jamie Whitfield, Matthew S. Palmer and Lawrence L. Spriet
Ice hockey is a fast, intense, and highly tactile sport, especially as skill levels increase. Past research has shown skill and decision-making performance decrements in “stop-and-go” sports, such as basketball, soccer, and ice hockey, in players who become mildly dehydrated and lose as little as
Sabrina Skorski, Iñigo Mujika, Laurent Bosquet, Romain Meeusen, Aaron J. Coutts and Tim Meyer
performance decrement as well as their time course to recover. 11 Metabolic Recovery The elevated energy expenditure caused by training and competition reduces substrate availability, which can decrease performance capacity. In high-intensity exercise, any decrease in substrate availability has the potential
Jenny H. Conviser, Amanda Schlitzer Tierney and Riley Nickols
severity of EDs are underestimated, especially when the athlete is performing well, creating a false sense of health and wellness. In addition, athletes will characteristically work hard to meet the demands of the sport and mask any emerging performance deficiencies. Performance decrements and medical
Anne Krendl, Izzy Gainsburg and Nalini Ambady
Although the effects of negative stereotypes and observer pressure on athletic performance have been well researched, the effects of positive stereotypes on performance, particularly in the presence of observers, is not known. In the current study, White males watched a video either depicting Whites basketball players as the best free throwers in the NBA (positive stereotype), Black basketball players as the best free throwers in the NBA (negative stereotype), or a neutral sports video (control). Participants then shot a set of free throws, during which half the participants were also videotaped (observer condition), whereas the other half were not (no observer condition). Results demonstrated that positive stereotypes improved free throw performance, but only in the no observer condition. Interestingly, observer pressure interacted with the positive stereotype to lead to performance decrements. In the negative stereotype condition, performance decrements were observed both in the observer and no observer conditions.
Jon Law, Rich Masters, Steven R. Bray, Frank Eves and Isabella Bardswell
Butler and Baumeister (1998) suggested that performance decrement of a difficult skill-based task occurring only in the presence of a supportive audience could be explained by “a cautious performance style” (p. 1226). A potential alternative explanation stems from Masters’ (1992) contention that skill failure under pressure occurs when performers attempt to control motor performance using explicit knowledge. It was proposed that a skill acquired with minimal metaknowledge (i.e., a limited explicit knowledge base) would remain robust regardless of audience type. To test this hypothesis, a table tennis shot was learned with either a greater or a lesser bank of explicit task knowledge. Performance was subsequently assessed in the presence of observation-only audiences, supportive audiences, and adversarial audiences. Consistent with hypotheses, supportive audiences induced performance decrement in the explicit-learning group only. It was argued that supportive audiences engender higher levels of internally focused attention than do adversarial or observation-only audiences, increasing the chance of disruption to skill execution when performance characteristics involve a large amount of explicit processing.