Purpose: To compare between-tests changes in submaximal exercise heart rate (HRex, 3 min, 12 km/h) and the speed associated with 4 mmol/L of blood lactate (V4mmol) in soccer players to get insight into their level of agreement and respective sensitivity to changes in players’ fitness. Methods: A total of 19 elite professional players (23  y) performed 2 to 3 graded incremental treadmill tests (3-min stages interspersed with 1 min of passive recovery, starting speed 8 km/h, increment 2 km/h until exhaustion or 18 km/h if exhaustion was not reached before) over 1.5 seasons. The correlation between the changes in HRex and V4mmol was examined. Individual changes in the 2 variables were compared (>2 × typical error considered “clear”). Results: The changes in HRex and V4mmol were largely correlated (r = .82; 90% confidence interval, .65–.91). In more than 90% of the cases, when a clear individual change in HRex was observed, it was associated with a similar clear change in V4mmol (the same direction, improvement, or impairment of fitness) and conversely. Conclusions: When it comes to testing players submaximally, the present results suggest that practitioners can use HRex or V4mmol interchangeably with confidence. However, in comparison with a field-based standardized warm-up run (3–4 min, all players together), the value of a multistage incremental test with repeated blood lactate samplings is questionable for a monitoring purpose given its time, labor, cost, and poorer player buy-in.
Martin Buchheit, Ben M. Simpson and Mathieu Lacome
Jac Orie, Nico Hofman, Laurentius A. Meerhoff and Arno Knobbe
At the Olympic level, optimally distributing training intensity is crucial for maximizing performance. Purpose: The authors evaluated the effect of training-intensity distribution on anaerobic power as a substitute for 1500-m speed-skating performance in the 4 y leading up to an Olympic gold medal. Methods: During the preparation phase of the speed-skating season, anaerobic power was recorded periodically (n = 15) using the mean power (in watts) with a 30-s Wingate test. For each training session in the 4 wk prior to each Wingate test, the volume (in hours), training type (specific, simulation, nonspecific, and strength training), and the rating of perceived exertion (RPE; CR-10) were recorded. Results: Compared with the 8 lowest, the 7 highest-scoring tests were preceded by a significantly (P < .01) higher volume of strength training. Furthermore, the RPE distribution of the number of nonspecific training sessions was significantly different (P < .01). Significant (P < .05) correlations highlighted that a larger nonspecific training volume in the lower intensities RPE 2 (r = .735) and 3 (r = .592) was associated positively and the medium intensities RPE 4 (r = −.750) and 5 (r = −.579) negatively with Wingate performance. Conclusion: For the subject, the best results were attained with a high volume of strength training and the bulk of nonspecific training at RPE 2 and 3, and specifically not at the adjoining RPE 4 and 5. These findings are surprising given the aerobic nature of training at RPE 2 and 3 and the importance of anaerobic capacity in this middle-distance event.
Fabio Bertapelli, Stamatis Agiovlasitis, Robert W. Motl, Roberto A. Soares, Marcos M. de Barros-Filho, Wilson D. do Amaral-Junior and Gil Guerra-Junior
The purpose of this study was to develop and cross-validate an equation for estimating percentage body fat (%BF) from body mass index and other potential independent variables among young persons with intellectual disability. Participants were 128 persons with intellectual disability (62 women; age 16–24 years) split between development (n = 98) and cross-validation (n = 30) samples. Dual-energy X-ray absorptiometry served as the reference method for %BF. An equation including 1/body mass index and sex (0 = male; 1 = female) was highly accurate in estimating %BF (p < .001; R 2 = .82; standard error of estimate = 5.22%). Mean absolute and root mean square errors were small (3.1% and 3.9%, respectively). A Bland–Altman plot indicated nearly zero mean difference between actual and predicted %BF with modest 95% confidence intervals. The prediction equation was %BF = 56.708 − (729.200 × [1/body mass index]) + (12.134 × sex). Health care professionals may use the prediction equation for monitoring %BF among young people with intellectual disability.
Chung-Ju Huang, Hsin-Yu Tu, Ming-Chun Hsueh, Yi-Hsiang Chiu, Mei-Yao Huang and Chien-Chih Chou
This study examined the effects of acute aerobic exercise on sustained attention and discriminatory ability of children with and without learning disabilities (LD). Fifty-one children with LD and 49 typically developing children were randomly assigned to exercise or control groups. The participants in the exercise groups performed a 30-min session of moderate-intensity aerobic exercise, whereas the control groups watched a running/exercise-related video. Neuropsychological tasks, the Daueraufmerksamkeit sustained attention test, and the determination tests were assessed before and after each treatment. Exercise significantly benefited performance in sustained attention and discriminatory ability, particularly in higher accuracy rate and shorter reaction time. In addition, the LD exercise group demonstrated greater improvement than the typically developing exercise group. The findings suggest that the acute aerobic exercise influenced the sustained attention and the discriminatory function in children with LD by enhancing regulation of mental states and allocation of attentional resources.
Tiago Duarte, Diane M. Culver and Kyle Paquette
The purpose of this paper is to delineate how an intervention aimed at increasing the learning capability of Canadian wheelchair curling coaches was framed by a systems convener in collaboration with stakeholders from different levels. Social learning theory, in particular a landscape of practice perspective, provides the conceptual framework. The methodology was collaborative inquiry with people from across the landscape to delineate the intervention strategies through cycles of reflection and action. The participants included parasport coaches, researchers, and Curling Canada technical leaders. Based on preintervention findings, the intervention was driven by (a) the use of technology to overcome barriers and the implementation of learning activities at competitions, (b) the use of a collective learning map to promote meaningful learning, (c) the involvement of the sport organization leadership to promote the participation of influential people, and (d) a reflection of how subpar outcomes occurred when the systems convener failed to engage with the sport organization leadership. The discussion sheds light on the many roles of systems conveners and the importance of promoting strategic and enabling values. Sport organizations should engage a systems convener who can effectively align learning goals with the available resources and the strategic mission of the organization.
Giuseppe delli Paoli, Denise van de Laarschot, Edith C.H. Friesema, Remco Verkaik, Antonia Giacco, Rosalba Senese, Pascal P. Arp, P. Mila Jhamai, Stefano M. Pagnotta, Linda Broer, André G. Uitterlinden, Antonia Lanni, M. Carola Zillikens and Pieter de Lange
Fasting enhances the beneficial metabolic outcomes of exercise; however, it is unknown whether body composition is favorably modified on the short term. A baseline–follow-up study was carried out to assess the effect of an established protocol involving short-term combined exercise with fasting on body composition. One hundred seven recreationally exercising males underwent a 10-day intervention across 15 fitness centers in the Netherlands involving a 3-day gradual decrease of food intake, a 3-day period with extremely low caloric intake, and a gradual 4-day increase to initial caloric intake, with daily 30-min submaximal cycling. Using dual-energy X-ray absorptiometry analysis, all subjects substantially lost total body mass (−3.9 ± 1.9 kg; p < .001) and fat mass (−3.3 ± 1.3 kg; p < .001). Average lean mass was lost (−0.6 ± 1.5 kg; p < .001), but lean mass as a percentage of total body mass was not reduced. The authors observed a loss of −3.9 ± 1.9% android fat over total fat mass (p < .001), a loss of −2.2 ± 1.9% gynoid over total fat mass (p < .001), and reduced android/gynoid ratios (−0.05 ± 0.1; p < .001). Analyzing 15 preselected single-nucleotide polymorphisms in 13 metabolism-related genes revealed trending associations for thyroid state–related single-nucleotide polymorphisms rs225014 (deiodinase 2) and rs35767 (insulin-like growth factor1), and rs1053049 (PPARD). In conclusion, a short period of combined fasting and exercise leads to a substantial loss of body and fat mass without a loss of lean mass as a percentage of total mass.
Samuel J. Callaghan, Robert G. Lockie, Walter Yu, Warren A. Andrews, Robert F. Chipchase and Sophia Nimphius
Purpose: To investigate whether changes in delivery length (ie, short, good, and full) lead to alterations in whole-body biomechanical loading as determined by ground reaction force during front-foot contact of the delivery stride for pace bowlers. Current load-monitoring practices of pace bowling in cricket assume equivocal biomechanical loading as only the total number of deliveries are monitored irrespective of delivery length. Methods: A total of 16 male pace bowlers completed a 2-over spell at maximum intensity while targeting different delivery lengths (short, 7–10 m; good, 4–7 m; and full, 0–4 m from the batter’s stumps). In-ground force plates were used to determine discrete (vertical and braking force, impulse, and loading rates) and continuous front-foot contact ground reaction force. Repeated-measures analysis of variance (P < .05), effects size, and statistical parametrical mapping were used to determine differences between delivery lengths. Results: There were no significant differences between short, good, and full delivery lengths for the discrete and continuous kinetic variables investigated (P = .19–1.00), with trivial to small effect sizes. Conclusion: There were minimal differences in front-foot contact biomechanics for deliveries of different lengths (ie, short, good, and full). These data reinforce current pace bowling load-monitoring practices (ie, counting the number of deliveries), as changes in delivery length do not affect the whole-body biomechanical loading experienced by pace bowlers. This is of practical importance as it retains simplicity in load-monitoring practice that is used widely across different competition levels and ages.
Mark R. Noon, Emma L.J. Eyre, Matthew Ellis, Tony D. Myers, Rhys O. Morris, Peter D. Mundy, Ryan Penny and Neil D. Clarke
Purpose: To investigate the influence of recruitment age on retention and release across the development pathway and to explore the influence of anthropometric and physical characteristics on retention and release at different ages throughout the development pathway and the likelihood of obtaining a professional contract. Methods: Following receipt of ethics approval, a cross-sectional study tracking 4 cohorts of players over 5 years assessed 76 male youth football players (11–16 y) from an English football academy on 3 occasions annually in anthropometry, countermovement jump height, and linear (30 and 15 m) and multidirectional sprint time. Players were categorized based on their start and release date. Results: Starting early (ie, before U12) in an academy was a key indicator of obtaining a professional contract, representing 87% of the players signed. Bayesian regression models suggest that the majority of differences in physical characteristics between players that were released and retained are trivial, small, and/or uncertain. Players who attained a professional contract at 18 had slower 15- and 30-m sprint times at U13 to U15 (P > 0 = .87–.99), slower multidirectional sprint times at U14 (P > 0 = .99), and lower countermovement jump height at U13 to U16 (P > 0 = .88–.99) compared with players who did not gain a contract. Conclusion: Players recruited early have an increased likelihood of gaining a professional contract. Physical assessments lack utility when used in isolation as a talent-identification tool.
Marni J. Simpson, David G. Jenkins and Vincent G. Kelly
Purpose: To examine potential differences in internal and external workload variables between playing positions and between training drills and games within an elite netball team during training and competition. Methods: Nine elite female netballers were monitored during 15 games and all training sessions over 28 weeks. Workload variables assessed were relative PlayerLoad (PL per minute), accelerations, decelerations, jumps, changes of direction, high-intensity events, medium-intensity events, low-intensity events, PL in a forward direction, PL in a sideways direction, PL in a vertical direction, and summated heart-rate zones using heart-rate monitors and inertial measurement units. Results: Conditioning and match play during training were the only drills that matched or exceeded game workloads. Workloads during small-sided games were lower than game workloads for all variables. In games, goalkeeper, goal attack, and goal shooter had a greater frequency of jumps compared with other positions. Midcourt positions had a greater frequency of low-intensity events in a game. Conclusions: Workloads during small-sided games were lower than game workloads across all external and internal variables; therefore, netball staff should modify these small-sided games if they wish them to develop game-based qualities. Specific game workload variables indicate that there are differences within some positional groups; coaches need to be aware that positional groupings may fail to account for differences in workload between individual playing positions.
Ric Lovell, Sam Halley, Jason Siegler, Tony Wignell, Aaron J. Coutts and Tim Massard
Purpose: To examine the concurrent and construct validity of numerically blinded ratings of perceived exertion (RPEs). Methods: A total of 30 elite male youth soccer players (age 16.7 [0.5] y) were monitored during training and matches over a 17-wk in-season period. The players’ external loads were determined via raw 10-Hz global positioning system. Heart rate (HR) was collected continuously and expressed as Bannister and Edwards training impulses, and minutes >80% of the players predetermined the maximum HR by the Yo-Yo Intermittent Recovery Test Level 1. RPE was collected confidentially 10 to 15 min after training/matches using 2 methods: (1) a traditional verbal response to the 0 to 100 category-ratio “centiMax” scale (RPE) and (2) numerically blinded RPE centiMax scale (RPEblind) with the response selected manually via a 5 × 7-in tablet “slider.” The RPE and RPEblind were divided by 10 and multiplied by the duration to derive the sessional RPE. Linear mixed models compared ratings, and within-subject repeated-measures correlations assessed the sessional RPE versus HR and external load associations. Results: There were no differences between the RPE and RPEblind (0.19; 95% confidence intervals, −0.59 to 0.20 au, P = .326) or their session values (13.5; 95% confidence intervals, −17.0 to 44.0 au, P = .386), and the ratings were nearly perfectly correlated (r = .96). The associations between the sessional RPE versus HR and external load metrics were large to very large (r = .65–.81), with no differences between the RPE methods (P ≥ .50). The RPEblind also reduced verbal anchor clustering and integer bias by 11% and 50%, respectively. Conclusions: RPEblind demonstrated concurrent and construct validity versus the traditional method, and may be used in situations where practitioners have concerns regarding the authenticity of athlete ratings.