Basketball Performance Is Related to Maturity and Relative Age in Elite Adolescent Players.

During a national championship, the anthropometric, physiological, and maturation characteristics of 13- to 14-year-old players of elite basketball teams and their association with sport performance were analyzed. Body parameters (weight, height, skinfold thicknesses, and lengths) were measured and physiological capacities assessed by sprint (20 m) and jump tests (i.e., countermovement jump with arm swing). Chronological age (CA) and maturity offset (years from age at peak height velocity; YAPHV) were calculated, and then predicted age at peak height velocity, as the difference between CA and YAPHV. Game performance was assessed with point averages and the performance index rating (PIR). The birth-date distribution of players was biased, those born early in the selection year outnumbering those born later. Anthropometric analysis indicated that players who performed better had longer body lengths. Physiological testing showed that semi-finalists had better sprint performance than quarter-finalists and those players with greater jump capacity scored more points. Early maturation and advanced maturity status were also associated with better PIR and scored points per game. Multiple blockwise regression analysis showed that, among the factors analyzed, YAPHV was the best predictor of basketball performance. In conclusion, around puberty, physical and physiological parameters associated with maturity and CA are important in determining the success of elite basketball players. Consequently, boys who are born in the second half of the year and/or late maturing tend to be marginalized or totally excluded, and not given the chance to play under equal conditions; their careers may then be held back by the relative disadvantage associated with inexperience.

Cell damage, antioxidant status, and cortisol levels related to nutrition in ski mountaineering during a two-day race.

The aim of this study was to measure the effect of nutrition on cell damage, antioxidant enzymes, and cortisol during a two-day ski mountaineering competition. Twenty-one male skiers participated in the study. Creatine kinase (CK), aspartate aminotransferase (AST), alanine aminotransferase (ALT), γ-glutamyl transpeptidase (GGT), lactate dehydrogenase (LDH), alkaline phosphatase (AP), cortisol and C-reactive protein (CRP), glutathione peroxidase (GPx) and reductase activities (GR) and C-reactive protein (CRP) levels, total antioxidant status, and cortisol levels were measured in serum the day before and immediately after the race. Their diet was also analysed during the competition. Enzymes and cortisol levels significantly increased after the competition. CK and LDH and cortisol levels were negatively correlated to total energy, protein, and fat intake. Intake of vitamin A, B1, B2, B6 and niacin was negatively correlated to LDH and AP. A negative correlation was also found between CK activity and Na, Fe, and Zn intake. Cortisol levels were negatively correlated to the intake of vitamins C, B1 and B2, and niacin. A positive correlation was found between serum GPx and intake of energy, carbohydrates, proteins, A and B vitamins, and folic acid. Skiers with the lowest nutrient intake during the competition were the ones who showed greater cell damage and lower antioxidant enzyme activity and cortisol levels, which may impair performance and also cause injuries and accidents. Particularly, skiers should have high intakes of total energy, macronutrients, vitamins A and B, Na, Zn, and Fe in order to decrease the deleterious effect of strenuous exercise. Key pointsA two-day ski mountaineering race produced muscle cell damage and oxidative stress and an increase in cortisol levels.There was a marked insufficient intake of carbohydrates which has been shown to affect performanceThose skiers with lowest nutrient intake showed greater cell damage, lower antioxidant activity and higher cortisol levels.Nutrition should be carefully monitored and assessed in order to minimize the mentioned blood changes to avoid fatigue, injuries and also accidents in this type of sport; particularly when skiers must carry their own food.

Anthropometric and physiological differences between first team and reserve soccer players aged 10-14 years at the beginning and end of the season.

The aim of this article was to identify differences in the anthropometric and physiological characteristics of first team and reserve young soccer players (10-14 years old) at both the beginning and end of the soccer season. Body composition was calculated by measuring weight, height, skinfold, limb circumference, and joint diameter. Vo2max was estimated by Astrand's test. Sprint and jump tests were also performed. In general, first team players (FTPs) were taller and leaner. However, the most relevant difference that we found at the beginning of the season was that FTPs had shorter sprint times than reserves in the 30-m test (both flat and with 10 cones). Moreover, these differences in sprint time were more marked at the end of the season. In addition, jump test performance by the reserves declined from the beginning to the end of the season. These results indicate that sprint time is an important factor associated with selection as an FTP between the ages of 10 and 14 years. The progression of the FTPs during the course of the season is better than that of the reserves and is associated with a different degree of growth and maturity. These findings should be taken into account by trainers and coaches to avoid a bias against late maturing or younger soccer players.