RESUMEN
PURPOSE: To describe cross-sectional age differences in change-of-direction performance (CODp) in female football players and investigate the relationship between CODp and linear-sprint speed, muscle power, and body size. METHODS: A sample of 135 well-trained female football players was divided into 8 age groups. Anthropometry (height, body mass, and lean body mass) and athletic performance (10-m sprint speed, 10-m×5-CODp, and 5-step bounding distance) were compared to determine interage differences using ANOVA. Then, the participants were divided into 3 age groups: 12- to 14-y-olds, 15- to 17-y-olds, and ≥18 y-olds. Simple- and multiple-regression analyses were conducted to determine the correlation between CODp and the other measurement variables in each age group. RESULTS: Age-related differences were found for CODp (F=10.41, P<.01), sprint speed (F=3.27, P<.01), and bounding distance (F=4.20, P<.01). Post hoc analysis revealed that the CODp of 17-y-old players was faster than that of 16-y-old players (P<.01), with no interage differences in sprint speed and bounding distance. Sprint speed and bounding distance were weakly correlated with CODp in 15- to ≥18-y-old players, but only sprint speed was correlated with CODp in 12- to 14-y-old players. CONCLUSIONS: CODp improves from 16 to 17 y of age in female players. Linear-sprint speed, muscle power, and body size were weakly correlated with the age differences in CODp.
Asunto(s)
Rendimiento Atlético , Fútbol Americano/fisiología , Aptitud Física/fisiología , Carrera/fisiología , Adolescente , Distribución por Edad , Factores de Edad , Niño , Estudios Transversales , Femenino , Humanos , Fuerza Muscular/fisiología , Adulto JovenRESUMEN
PURPOSE: T1WI (T1 weighted image) was acquired in order to grade bone fusion following the studies by FIFA (Federation Internationale de Football Associations). Research using images other than T1WI has not been reported. The aim of this study is to evaluate the grade of epiphyseal fusion by T2* weighted images (T2*WI) and to investigate new findings on T2*WI as compared with T1WI. METHODS: A total of 87 subjects, all junior football players between the ages of 12 and 17 years old, were examined. T1 and T2* WI were obtained using a 1.2T Open type MR system. The T1WI and T2*WI were rated twice randomly by four radiologists using the FIFA grading system. RESULTS: The intra-rater reliability for grading was higher in T1WI (The Intraclass Correlation Coefficient (ICC)=0.949-0.985) than in T2*WI (ICC=0.917-0.943). The inter-rater reliability for grading was also higher in T1WI (ICC=0.923) than in T2*WI (ICC=0.867). CONCLUSIONS: This research showed that T1WI is a better sequence than T2*WI to evaluate bone fusion following FIFA protocol. It was speculated that the reason for this is that T1WI has higher tissue contrast resolution and enables clearer images of the epiphyseal fusion than T2*WI and the grading system by T1WI was not suitable for T2*WI.
RESUMEN
INTRODUCTION: Acupuncture is used to modulate the physical well-being of athletes in Asian countries. However, there is little information on the immediate effects of acupuncture treatment on physiological or psychological responses to exercise. PURPOSE: The purpose of this study was to examine the effect of acupuncture treatment on the physical well-being of elite female soccer players during a competition period. METHODS: Subjects were divided into two groups: those who received acupuncture treatment (18.1 +/- 2.3 yr [+/-SD], N = 9) and a control group (17.7 +/- 2.8 yr, N = 12). In the treatment group, acupuncture stimulus was applied at LI 4 (Goukoku), ST 36 (Ashi-sanri) for 20 min, and ST 6 (Kyosya), LU 6 (Ko-sai) points for 15 min 4 h after the game every night during the competition period. The measured parameters included salivary secretory immunoglobulin A (SIgA) level, cortisol level in saliva, subjective rating of physical well-being, and profile of mood states (POMS). RESULTS: The following were the main results: 1). Exercise-induced decrease of salivary SIgA and increase of salivary cortisol were inhibited by acupuncture. 2). Acupuncture improved subjective rating of muscle tension and fatigue. 3). The POMS score was modulated by acupuncture. CONCLUSION: These results support the effectiveness of acupuncture for physical and mental well-being of athletes.