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- Caparrós, T., et al.
(author)
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The relationship of practice exposure and injury rate on game performance and season success in professional male basketball
- 2016
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In: Journal of Sports Science and Medicine. - 1303-2968. ; 15:3, s. 397-402
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Journal article (peer-reviewed)abstract
- The objectives of this study were to determine the relationship among game performance, injury rate, and practice exposure in a professional male basketball team. A retroospective analysis of prospective collected data was conducted over seven consecutive seasons (2007/2008 to 2013/2014). Data collection included sports performance during competition (statistical evaluation), injury rate, and total exposure (games and practices). Over the surveillance period, 162 injuries (91 practice; 71 matches) occurred over 32,668 hours of exposure (556 games and 2005 practices). There was a strong positive correlation between: 1) exposure (total number of practices and hours of exposure) and the total number of injuries (r = 0.77; p = 0.04); 2) exposure (total hours of exposure and total hours of practice exposure) and performance (total team ranking) (r = 0.77 and p = 0.04, and r = 0.8 and p = 0.03, respectively); and 3) total number of injuries and performance (total team ranking) (r = 0.84; p = 0.02). While increasing practice and competition time is related to greater team performance, it also increases the number of injuries. However, higher injury rates were not associated with worse overall team performance. Efforts to reduce high-risk activity during practice, optimally replaced with injury prevention training, might help to reduce injury risk. © Journal of Sports Science and Medicine.
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- Edvardsson, Arne, et al.
(author)
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Is a cognitive-behavioural biofeedback intervention useful to reduce injury risk in junior football players?
- 2012
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In: Journal of Sports Science and Medicine (JSSM). - Bursa, Turkey : Journal of Sports Science and Medicine. - 1303-2968. ; 11:2, s. 331-338
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Journal article (peer-reviewed)abstract
- Athletes participating in sport are exposed to a relatively high injury risk. Previous research has suggested that it could be possible to reduce sports injuries through psychological skills training. The purpose of this study was to examine the extent to which a cognitive behavioural biofeedback intervention could reduce the number of sports injuries in a sample of players in Swedish elite football high schools. Participants from four elite football high schools (16-19 years old) were divided into one experiment (n = 13) and one control group (n = 14). Participants were asked to complete three questionnaires to assess anxiety level (Sport Anxiety Scale), history of stressors (Life Event Scale for Collegiate Athletes) and coping skills (Athletic Coping Skills Inventory - 28) in a baseline measure. Mann-Whitney Utests showed no significant differences in pre-intervention scores based on the questionnaires. The experimental group participated in a nine-week intervention period consisting of seven sessions, including: somatic relaxation, thought stopping, emotions/problem focused coping, goal setting, biofeedback training as well as keeping a critical incident diary. A Mann-Whitney U test showed no significant difference between the control and experimental group U (n1 = 13, n2 = 14) = 51.00, p = 0.054. However, considering the small sample, the statistical power (0.05 for present study), to detect effects was low. The results of the study are discussed from a psychological perspective and proposals for future research are given. © Journal of Sports Science and Medicine.
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- Gerber, M, et al.
(author)
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Concerns regarding hair cortisol as a biomarker of chronic stress in exercise and sport science
- 2012
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In: Journal of Sports Science and Medicine. - 1303-2968. ; 11, s. 571-581
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Research review (peer-reviewed)abstract
- Hair cortisol has the potential to fill the methodological void of long-term cortisol assessment while becoming a widely accepted measure in biopsychology. This review critically examines the applicability and relevance of hair cortisol measurement specifically within the field of exercise and sport science. Current measures of the HPA axis only cover a brief time period, whereas hair cortisol is a unique, non-invasive means to capture long-term cortisol secretion. Studies have shown that individuals who have elevated cortisol secretion (e.g. due to diseases associated with a disturbed activation of the HPA axis or exposure to stressful life events) reveal increased hair cortisol. By contrast, only weak correlations exist between hair cortisol and perceived stress, and the direction of the relationship between hair cortisol levels and mental disorders is unclear. Acute exercise, however, results in increased levels of cortisol that eventually is reflected in higher levels of cortisol in hair samples and studies have shown that exercise intensity is related to hair cortisol level. Thus, elevated hair cortisol levels found among regular exercisers are not necessarily pathological. Thus, one should practice caution when associating athletes’ elevated hair cortisol with poor mental health or disease. Hair cortisol analysis can contribute to a more complete understanding of how long-term cortisol elevation mediates stress-related effects on the health and performance of recreational exercisers and elite athletes. Nevertheless, it is crucial for exercise and sport scientists to consider whether their research questions can be adequately addressed, given that regular intense exercise results in substantially augmented hair cortisol levels.
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- Ivarsson, Andreas, et al.
(author)
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Psychological factors as predictors of injuries among senior soccer players : a prospective study
- 2010
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In: Journal of Sports Science and Medicine (JSSM). - Bursa, Turkey : Dept. of Sports Medicine, Medical Faculty of Uludag University. - 1303-2968. ; 9:2, s. 347-352
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Journal article (peer-reviewed)abstract
- It is reported that between 65–91% of elite soccer players in Sweden have at least one injury per year (Hägglund, 2007). Several studies define different physiological and psychological factors affecting athletic injury-risk. A number of models contain proposals that specify relationships between psychological factors and an increased athletic injury-risk. Examples include Williams and Andersen’s (1998) stress-injury model and Johnson and Ivarsson’s (in press) empirical model of injury risk factors which proposes that factors such as trait anxiety and ineffective coping skills are influential. The purpose of this study was to examine the relationship between (a) personality factors, b) coping variables, and (c) stress and injury risk. Participants were 48 male soccer players from 3 Swedish teams ranging in age from 16 to 36 years (M = 22 years). Participants completed 5 questionnaires: Football Worry Scale, Swedish universities Scales of Personality, Life Events Survey for Collegiate Athletes, Daily Hassle Scale and Brief COPE. Information on injuries was collected by athletic trainers of the teams over 3-months. Results suggest injury was significantly predicted by 4 personality trait predictors: somatic trait anxiety, psychic trait anxiety, stress susceptibility, and trait irritability. Collectively, the predictors self-blame and acceptance could explain 14.6% of injury occurrence. More injuries were reported among players who score high in daily hassles. These results support previous findings (e.g. Fawkner et al., 1999). Recommendations are given for both the athletes and the trainers on working to prevent sport injuries.
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- Metaxas, Thomas I, et al.
(author)
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Muscle fiber characteristics, satellite cells and soccer performance in young athletes.
- 2014
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In: Journal of Sports Science and Medicine (JSSM). - 1303-2968. ; 13:3, s. 493-501
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Journal article (peer-reviewed)abstract
- This study is aimed to examine the muscle fiber type, composition and satellite cells in young male soccer players and to correlate them to cardiorespiratory indices and muscle strength. The participants formed three Groups: Group A (n = 13), 11.2 ± 0.4yrs, Group B (n=10), 13.1 ± 0.5yrs and Group C (n = 9), 15.2 ± 0.6yrs. Muscle biopsies were obtained from the vastus lateralis. Peak torque values of the quadriceps and hamstrings were recorded and VO2max was measured on the treadmill. Group C had lower type I percentage distribution compared to A by 21.3% (p < 0.01), while the type IIA relative percentage was higher by 18.1% and 18.4% than in Groups A and B (p < 0.05). Groups B and C had higher cross-sectional area (CSA) values in all fiber types than in Group A (0.05 < p < 0.001). The number of satellite cells did not differ between the groups. Groups B and C had higher peak torque at all angular velocities and absolute VO2max in terms of ml·min(-1) than Group A (0.05 < p < 0.001). It is concluded that the increased percentage of type IIA muscle fibers noticed in Group C in comparison to the Groups A and B should be mainly attributed to the different workload exercise and training programs. The alteration of myosin heavy chain (MHC) isoforms composition even in children is an important mechanism for skeletal muscle characteristics. Finally, CSA, isokinetic muscle strength and VO2max values seems to be expressed according to age. Key PointsFifteen years old soccer players have higher IIA percentage distribution than the younger players by approximately 18%.The age and the training status play a crucial role in muscle fibers co-expression.Specific training in young athletes seems to alter significantly the muscular metabolic profile.
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| 10. |
- Mishica, Christina, et al.
(author)
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Relationships between Heart Rate Variability, Sleep Duration, Cortisol and Physical Training in Young Athletes
- 2021
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In: Journal of Sports Science and Medicine (JSSM). - : Department of Sports Medicine, Medical Faculty of Uludag University. - 1303-2968. ; 20:4, s. 778-788
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Journal article (peer-reviewed)abstract
- The aims of the current study were to examine the relationships between heart rate variability (HRV), salivary cortisol, sleep duration and training in young athletes. Eight athletes (16 ± 1 years) were monitored for 7 weeks during training and competition seasons. Subjects were training for endurance-based winter sports (cross-country skiing and biathlon). Training was divided into two zones (K1, easy training and K2, hard training). Heart rate and blood lactate during submaximal running tests (SRT), as well as cortisol, sleep duration and nocturnal HRV (RMSSD), were determined every other week. HRV and cortisol levels were correlated throughout the 7-week period (r = -0.552, P = 0.01), with the strongest correlation during week 7 (r = -0.879, P = 0.01). The relative changes in K1 and HRV showed a positive correlation from weeks 1-3 (r = 0.863, P = 0.006) and a negative correlation during weeks 3-5 (r = -0.760, P = 0.029). The relative change in sleep during weeks 1-3 were negatively correlated with cortisol (r = -0.762, P = 0.028) and K2 (r = -0.762, P = 0.028). In conclusion, HRV appears to reflect the recovery of young athletes during high loads of physical and/or physiological stress. Cortisol levels also reflected this recovery, but significant change required a longer period than HRV, suggesting that cortisol may be less sensitive to stress than HRV. Moreover, our results indicated that during the competition season, recovery for young endurance athletes increased in duration and additional sleep may be beneficial.
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