The PWC170: comparison of different stage lengths in 11-16 year olds.

Department of Kinesiology, Michigan State University, 27 IM Sports Circle, East Lansing, MI, USA.
Arbeitsphysiologie (Impact Factor: 2.3). 09/2011; 112(5):1955-61. DOI: 10.1007/s00421-011-2157-z
Source: PubMed

ABSTRACT It is unknown how the estimation of aerobic fitness in children and adolescents compares among physical working capacity (PWC) protocols with different stage lengths. The purpose of this study was twofold: (1) compare PWC tests with 2-, 3-, and 6-min stage lengths in youth, and (2) examine the relationship between PWC at a heart rate (HR) of 170 beats min(-1) (PWC170) and peak oxygen consumption (VO(2)peak). Fifty youth (31 m, 19 f), aged 11-16 years participated. Each participant visited the laboratory twice and performed three PWC tests (2-, 3-, 6-min stages) on a cycle ergometer. Tests usually consisted of three stages of increasing loads with the goal of reaching HR ≥ 165 beats min(-1). Individual regression lines were created to predict workload at HR = 170 beats ∙ min(-1) for each test. Participants completed two VO(2peak) tests, both running and cycling. Repeated measures ANOVA was used to compare PWC170 values. Pearson correlation was used to assess the relationships between VO(2peak) and power output for different PWC170 stage lengths. The three PWC170 protocols differ significantly; therefore, it is not advisable to directly compare results from different protocols. Furthermore, PWC170 showed moderate associations with VO(2peak), with the 2-min protocol showing the best correlation.

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    Sport Sciences for Health 07/2014;
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    ABSTRACT: Purpose. The aim of this study was to examine the relationship between player position and physical fitness, with an emphasis on anaerobic power, in female soccer players. Methods. For this purpose, 54 first league female soccer players were recruited. They included goalkeepers (n = 4, age 22.89 ± 4.37 years), defenders (n = 21, 21.92 ± 3.81 years), midfielders (n = 22, 21.71 ± 4.70 years) and attackers (n = 7, 20.43 ± 4.70 years). Participants’ anthropometric characteristics were measured and a physical fitness test battery was administered. Results. Significant differences were observed in body fat percentage (F3,50 = 3.06, p = 0.036, ŋ2 = 0.16) with goalkeepers being fatter than defenders (mean difference 6.1%; 95% CI 0.3,11.9). Positional differences were also found in the sit-and-reach test (F3,50 = 4.46, p = 0.007, ŋ2 = 0.21), in which goalkeepers scored lower than defenders (–11.4 cm; 95% CI –21.4, –1.5) and midfielders (–10.0 cm; 95% CI –19.9, 0). Comparison of fat mass and endomorphy were statistically significant (p = 0.057 and p = 0.062, respectively), with goalkeepers showing the highest values; these differences were in the same direction as with body fat percentage. No positional differences were found in the other physical fitness components (aerobic capacity, anaerobic power, and muscle strength). Conclusions. Differences among player positions were observed in body composition (highest body fat percentage in goalkeepers) and flexibility (lowest score in goalkeepers). These trends are in agreement with previously published data concerning elite soccer players. These findings might be used as reference data by coaches and trainers to identify talent, select players, and monitor training.
    Human Movement 07/2014; 15(2):74-79.
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    ABSTRACT: The main aim of this study was to examine differences in physical and physiological characteristics, with an emphasis on anaerobic power, of male basketball players by age and playing position. Methods. Basketball players (n=101), classified into three age groups: under 15 yrs (U-15, n=35, 14.28±0.72 yrs), under 18 yrs (U-18, n=35, 16.23±0.74 yrs) and older than 18 yrs (Elite, n=31, 25.66±5.09 yrs), participated in this study. The variables under examination were anthropometric characteristics, body composition, physical working capacity test, 3 min step test, Wingate anaerobic test, force-velocity test, sit-and-reach test, handgrip strength test and countermovement vertical jump with arm-swing. Results. U-15, U-18 and elite players differed for all aforementioned parameters with the older group scoring better than the younger (η2≥0.06, p<0.048). In Elite group, centers were heavier and taller than guards (22.3 kg and 20.9 cm, respectively) and forwards (14.3 kg and 10.6 cm), and forwards were taller than guards (10.2 cm). Guards scores were higher than centers in maximal power (3.61 ) and in peak power (1.39 Forwards scored higher than centers in mean power (1.25 In the U-18 group, guards were stronger in the relative strength than centers (2.4 In the U-15 group, centers were taller than guards (17.8 cm) and forwards (9.7 cm), and forwards were also taller than guards (8.1 cm). Conclusions. Based on the findings of this study, it is concluded that positional differences, especially in anaerobic power, in male basketball vary by age. Thus, young basketball players should not be regarded as miniature adult basketball players with regards to their physical and physiological characteristics, and their positional specialization.
    Sport Sciences for Health 07/2014; epub ahead of print..