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: 2.66). 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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    ABSTRACT: Whereas nutrition has a crucial role on sport performance, it is not clear to what extend nutrition knowledge is associated with physical fitness. The aim of this study was to examine the current level of nutrition knowledge of soccer players and whether this level is associated with physical fitness. Soccer players (n=185, aged 21.3±4.9 yr, weight 72.3±8.4 kg and height 177.5±6.4 cm) performed a battery of physical fitness tests (sit-and-reach test, SAR; physical working capacity in heart rate 170, PWC170; and Wingate anaerobic test, WAnT), and completed an 11-item nutrition knowledge questionnaire (NKQ). Low to moderate Pearson correlations (0.15<r<0.34, p<0.05) of NKQ with age, weight, height, fat free mass (FFM), SAR, peak power and mean power of WAnT were observed. Soccer players with high score in NKQ were older (4.4 yr (2.2;6.6), mean difference (95% confidence intervals)), heavier (4.5 kg (0.6;8.3)) with higher FFM (4.0 kg (1.1;6.8)) and peak power (59 W (2;116)) than their counterparts with low score. The moderate score in the NKQ suggests that soccer players should be targeted for nutrition education. Although the association between NKQ and physical fitness was low to moderate, there were indications that better nutrition knowledge might result in higher physical fitness and consequently soccer performance.
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    Sport Sciences for Health 07/2014;
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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..