The authors’ aim was to examine the prevalence of (daily) dietary-supplement (DS) use among elite adolescent athletes and to differentiate use by different types of DS according to their function. Data were analyzed for associations between users of these DS types, sociodemographic, sport-specific characteristics, and opinion on the need for DS. In addition, sources of supply and information were examined. In the framework of the GOAL Study, 1,138 German elite adolescent athletes (14–18 yr) answered questions about DS. The data were analyzed to identify groups at risk for using DS after a classification by supplemental function. Of the young athletes, 91.1% reported DS use during the previous month. (Daily) DS use was significantly associated with sex, kind of sport, and the weekly duration of sporting activity. Furthermore, some athletes were required to use DS by their sporting organization. DS use was more likely in these athletes than in those whose sporting organizations had no such requirement. Overall, DS with short- and long-term supplemental function were mostly associated with the use of magnesium. However, DS with medium-term muscle-building function played an important role among daily users. The main source of information about DS was coaches; main source of supply was parents. Professional education is urgently needed, as 9 out of 10 athletes used DS, and strong positive opinions toward the use of DS were present, particularly in the DS users.
Katharina Diehl, Ansgar Thiel, Stephan Zipfel, Jochen Mayer, Alexia Schnell and Sven Schneider
Tara K. Scanlan, Paul J. Carpenter, Jeffery P. Simons, Greg W. Schmidt and Bruce Keeler
This article introduces a sport-specific theoretical model of commitment. Sport commitment is defined as a psychological state representing the desire or resolve to continue sport participation. The Sport Commitment Model proposes that sport commitment is determined by sport enjoyment, involvement alternatives, personal investments, social constraints, and involvement opportunities. Greater sport enjoyment, personal investments, social constraints, involvement opportunities, and less attractive involvement alternatives are predicted to lead to higher levels of sport commitment. Constitutive definitions were established for each of the model's components, and questionnaire items were developed. Results from the first empirical test of the model conducted with girls (n = 95) and boys (n = 83) participating in a Little League program showed that the questionnaire items formed reliable scales. Correlational analyses demonstrated that several predictors were related to sport commitment as hypothesized. Stepwise regression findings revealed that sport enjoyment and personal investments were the dominant predictors of commitment for this sample. Together, these two model components accounted for 58% of the sport commitment variance.
Jeffrey J. Martin, Brigid Byrd, Michele Lewis Watts and Maana Dent
The purpose of the current study was to predict both general and sport-specific quality of life using measures of grit, hardiness, and resilience. Seventy-five adults (74 men, 1 woman) who are wheelchair basketball athletes participated in the current study. Twenty-six percent of the variance in life satisfaction was accounted for. Both hardiness and resilience accounted for meaningful variance, as indicated by their significant beta weights. Twenty-two percent of the variance in sport engagement was predicted; resilience and grit accounted for meaningful variance, as indicated by their significant beta weight. The regression results indicate that athletes reporting the highest levels of grit and resilience tended to also be the most engaged in their sport, and athletes with high levels of hardiness and resilience reported the highest quality of life. The descriptive results support an affirmation model of disability for the current sample of wheelchair athletes in that they reported moderate to strong levels of resiliency, grit, hardiness, sport engagement, and a high quality of life.
Thomas Paulson and Victoria Goosey-Tolfrey
Despite the growing interest in Paralympic sport, the evidence base for supporting elite wheelchair sport performance remains in its infancy when compared with able-bodied (AB) sport. Subsequently, current practice is often based on theory adapted from AB guidelines, with a heavy reliance on anecdotal evidence and practitioner experience. Many principles in training prescription and performance monitoring with wheelchair athletes are directly transferable from AB practice, including the periodization and tapering of athlete loads around competition, yet considerations for the physiological consequences of an athlete’s impairment and the interface between athlete and equipment are vital when targeting interventions to optimize in-competition performance. Researchers and practitioners are faced with the challenge of identifying and implementing reliable protocols that detect small but meaningful changes in impairment-specific physical capacities and on-court performance. Technologies to profile both linear and rotational on-court performance are an essential component of sport-science support to understand sport-specific movement profiles and prescribe training intensities. In addition, an individualized approach to the prescription of athlete training and optimization of the “wheelchair–user interface” is required, accounting for an athlete’s anthropometrics, sports classification, and positional role on court. In addition to enhancing physical capacities, interventions must focus on the integration of the athlete and his or her equipment, as well as techniques for limiting environmental influence on performance. Taken together, the optimization of wheelchair sport performance requires a multidisciplinary approach based on the individual requirements of each athlete.
Karen E. French and Jerry R. Thomas
This study examined the relationship of sport-specific knowledge to the development of children's skills in basketball. Two experiments were conducted. The first compared child expert and novice basketball players in two age leagues, 8-10 years and 11-12 years, on the individual components of basketball performance (control of the basketball, cognitive decisions, and motor execution) and on measures of basketball knowledge, dribbling skill, and shooting skill. Child expert players of both age groups possessed more shooting skill and more basketball knowledge. A canonical correlation analysis indicated that basketball knowledge was related to decision-making skill, whereas dribbling and shooting skill were related to the motor components of control and execution. Experiment 2 examined the changes in the individual components of performance, basketball knowledge, dribbling skill, and shooting skill from the beginning to the end of the season. Subjects improved in the cognitive decision-making and control components of performance across the course of the season, and basketball knowledge increased from the beginning to the end of the season. Only basketball knowledge was a significant predictor of the decision-making component at the end of the season. The overall results of Experiments 1 and 2 indicate that the development of the sport knowledge base plays a salient role in skilled sport performance of children.
Johanna M. Hurtubise, Cheryl Beech and Alison Macpherson
There is a lack of research on sex differences for severe injuries across a variety of sports at the collegiate level.
To compare differences in injury severity and concussion between sexes and collegiate sports.
Descriptive epidemiological study.
1,657 injuries were analyzed from collegiate teams at York University.
Data Collection and Analysis:
Injuries were assessed by a certified or student athletic therapist and were categorized based on degree of tissue and/or joint damage as either severe or nonsevere. Severe injuries included those with third degree damage, while all others were classified as nonsevere. Injury severity was compared between the sexes and across different sports using Pearson chisquare analysis. Logistic regression was used to assess the relative contribution of each covariate.
Males sustained 1,155 injuries, with 13.3% of them being severe, while females sustained only 502 injuries, 17.7% of which were severe. The odds of sustaining severe injuries among female athletes are 1.4 times the odds of male athletes (OR: 1.40, CI 1.05−1.86). Eleven percent of all female injuries were concussions—significantly more than males (χ2 = 11.03, p = .001). The odds of female athletes having a concussion are 1.9 times the odds of a male athlete (OR: 1.85, CI 1.28−2.67).
Based on our analysis, females are at an increased risk of sustaining a severe injury, particularly concussions. These findings highlight the need for future research into sex and sport-specific risk factors. This may provide information for health care professionals, coaches, and athletes for the proper prevention, on-field care, and treatment of sport injuries.
Peter M. Fowler, Rob Duffield, Donna Lu, Jeremy A. Hickmans and Tannath J. Scott
To examine the effects of 24-h travel west across 11 time zones on subjective jet-lag and wellness responses together with self-reported sleep and upper respiratory symptoms in 18 professional rugby league players.
Measures were obtained 1 or 2 d before (pretravel) and 2, 6, and 8 d after travel (post-2, post-6, and post-8) from Australia to the United Kingdom (UK) for the 2015 World Club Series.
Compared with pretravel, subjective jet-lag remained significantly elevated on post-8 (3.1 ± 2.3, P < .05, d > 0.90), although it was greatest on post-2 (4.1 ± 1.4). Self-reported sleep-onset times were significantly earlier on post-2 than at all other time points (P < .05, d > 0.90), and large effect sizes suggested that wake times were earlier on post-2 than on post-6 and post-8 (d > 0.90). Although significantly more upper respiratory symptoms were reported on post-6 than at pretravel (P < .05, d ˃ 0.90), no incidence of injury and negligible changes in wellness and muscle strength and range of motion (P > .05, d < 0.90) were evident after travel.
Results suggest that westward long-haul travel between Australia and the UK exacerbates subjective jet-lag and sleep responses, along with upper respiratory symptoms, in professional rugby league players. Of note, the increase in self-reported upper respiratory symptoms is a reminder that the demands of long-haul travel may be an additional concern in jet-lag for traveling athletes. However, due to the lack of sport-specific performance measures, it is still unclear whether international travel interferes with training to the extent that subsequent competition performance is impaired.
Daniel Gould, Linda Petlichkoff and Robert S. Weinberg
Two studies were conducted to examine antecedents of, relationships between, and temporal changes in the cognitive anxiety, somatic anxiety, and the self-confidence components of the Martens, Burton, Vealey, Bump, and Smith (1983) newly developed Competitive State Anxiety Inventory-2 (CSAI-2). In addition, the prediction that cognitive and somatic anxiety should differentially influence performance was examined. In Study 1, 37 elite intercollegiate wrestlers were administered the CSAI-2 immediately before two different competitions, whereas in Study 2, 63 female high school volleyball players completed the CSAI-2 on five different occasions (1 week, 48 hrs, 24 hrs, 2 hrs, and 20 min) prior to a major tournament. The results were analyzed using multiple regression, multivariate multiple regression, univariate and multivariate analyses of variance, and general linear model trend analysis techniques. The findings supported the scale development work of Martens and his colleagues by verifying that the CSAI-2 assesses three separate components of state anxiety. A number of other important findings also emerged. First, the prediction was confirmed that somatic anxiety increases during the time leading to competition, while cognitive anxiety and confidence remain constant. Second, CSAI-2 subscales were found to have different antecedents, although the precise predictions of Martens and his colleagues were not supported. Third, the prediction that cognitive anxiety would be a more powerful predictor of performance than somatic anxiety was only partially supported. Fourth, the prediction that precompetitive anxiety differences between experienced and inexperienced athletes initially found by Fenz (1975) result from somatic anxiety changes was not supported. It was concluded that the CSAI-2 shows much promise as a multidimensional sport-specific state anxiety inventory, although more research is needed to determine how and why specific antecedent factors influence various CSAI-2 components and to examine the predicted relationships between CSAI-2 components and performance.
Espen Tønnessen, Ida S. Svendsen, Bent R. Rønnestad, Jonny Hisdal, Thomas A. Haugen and Stephen Seiler
One year of training data from 8 elite orienteers were divided into a transition phase (TP), general preparatory phase (GPP), specific preparatory phase (SPP), and competition phase (CP). Average weekly training volume and frequency, hours at different intensities (zones 1–3), cross-training, running, orienteering, interval training, continuous training, and competition were calculated. Training volume was higher in GPP than TP, SPP, and CP (14.9 vs 9.7, 11.5, and 10.6 h/wk, P < .05). Training frequency was higher in GPP than TP (10 vs 7.5 sessions/wk, P < .05). Zone 1 training was higher in GPP than TP, SPP, and CP (11.3 vs 7.1, 8.3, and 7.7 h/wk, P < .05). Zone 3 training was higher in SPP and CP than in TP and GPP (0.9 and 1.1 vs 1.6 and 1.5 h/wk, P < .05). Cross-training was higher in GPP than SPP and CP (4.3 vs 0.8 h/wk, P < .05). Interval training was higher in GPP than TP, SPP, and CP (0.7 vs 0.3 h/wk, P < .05). High-intensity continuous training was higher in GPP than CP (0.9 vs 0.4 h/wk, P < .05), while competition was higher in SPP and CP than in TP and GPP (1.3 and 1.5 vs 0.6 and 0.3 h/wk, P < .01). In conclusion, these champion endurance athletes achieved a progressive reduction in total training volume from GPP to CP via a shortening of each individual session while the number of training sessions remained unchanged. This decrease in training volume was primarily due to a reduction in the number of hours of low-intensity, non-sport-specific cross-training.
Greg Henry, Brian Dawson, Brendan Lay and Warren Young
To study the validity of a video-based reactive agility test in Australian footballers.
15 higher performance, 15 lower performance, and 12 nonfootballers completed a light-based reactive agility test (LRAT), a video-based reactive agility test (VRAT), and a planned test (PLAN).
With skill groups pooled, agility time in PLAN (1346 ± 66 ms) was significantly faster (P = .001) than both reactive tests (VRAT = 1550 ± 102 ms; LRAT = 1572 ± 97 ms). In addition, decision time was significantly faster (P = .001; d = 0.8) in LRAT (278 ± 36 ms) than VRAT (311 ± 47 ms). The correlation in agility time between the two reactive tests (r = .75) was higher than between the planned and reactive tests (r = .41–.68). Higher performance players had faster agility and movement times on VRAT (agility, 130 ± 24 ms, d = 1.27, P = .004; movement, 69 ± 73 ms, d = 0.88, P = .1) and LRAT (agility, 95 ± 86 ms, d = 0.99, P = .08; movement, 79 ± 74 ms; d = 0.9; P = .08) than the nonfootballers. In addition, higher (55 ± 39 ms, d = 0.87, P = .05) and lower (40 ± 57 ms, d = 0.74, P = .18) performance groups exhibited somewhat faster agility time than nonfootballers on PLAN. Furthermore, higher performance players were somewhat faster than lower performance for agility time on the VRAT (63 ± 85 ms, d = 0.82, P = .16) and decision time on the LRAT (20 ± 39 ms, d = 0.66, P = .21), but there was little difference in PLAN agility time between these groups (15 ± 150 ms, d = 0.24, P = .8).
Differences in decision-making speed indicate that the sport-specific nature of the VRAT is not duplicated by a light-based stimulus. In addition, the VRAT is somewhat better able to discriminate different groups of Australian footballers than the LRAT. Collectively, this indicates that a video-based test is a more valid assessment tool for examining agility in Australian footballers.