Measurement of total energy expenditure by the doubly labelled water method in professional soccer players

To determine the daily energy requirements of professional soccer players during a competitive season, we measured total energy expenditure in seven players (age 22.1+/-1.9 years, height 1.75+/-0.05 m, mass 69.8+/-4.7 kg; mean +/- s) using the doubly labelled water method. Energy intake was simultaneously estimated from 7 day self-report dietary records. Mean total energy expenditure and energy intake were 14.8+/-1.7 MJ x day(-1) (3532+/-408 kcal x day(-1)) and 13.0+/-2.4 MJ x day(-1) (3113+/-581 kcal x day(-1)), respectively. Although there was a significant difference between total energy expenditure and energy intake (P < 0.01), there was a strong relationship between the two (r= 0.893, P< 0.01). Basal metabolic rate and recommended energy allowance calculated from the Recommended Dietary Allowances for the Japanese were 7.0+/-0.3 MJ x day(-1) (1683+/-81 kcal x day(-1)) and 15.6+/-0.8 MJ x day(-1) (3739+/-180 kcal x day(-1)), respectively. A physical activity level (total energy expenditure/ basal metabolic rate) of 2.11+/-0.30 indicated that, during the competitive season, professional soccer players undertake much routine physical activity, similar to that of competitive athletes during moderate training. Energy intake estimated using dietary records was under-reported, suggesting that its calculation from these data does not predict energy expenditure in soccer players.     

Analysis of performance in orienteering with treadmill tests and physiological field tests using a differential global positioning system

The aim of this study was to determine the physiological responses to orienteering by examining the interrelationships between the information provided by a differential global positioning system (dGPS) about an orienteer's route, speed and orienteering mistakes, portable metabolic gas analyser data during orienteering and data from incremental treadmill tests. Ten male orienteers completed a treadmill threshold test and a field test; the latter was performed on a 4.3 km course on mixed terrain with nine checkpoints. The anaerobic threshold, threshold of decompensated metabolic acidosis, respiratory exchange ratio, onset of blood lactate accumulation and peak oxygen uptake (VO2peak) were determined from the treadmill test. Time to complete the course, total distance covered, mean speed, distance and timing of orienteering mistakes, mean oxygen uptake, mean relative heart rate, mean respiratory exchange ratio and mean running economy were computed from the dGPS data and metabolic gas analyser data. Correlation analyses showed a relationship between a high anaerobic threshold and few orienteering mistakes (r = - 0.64, P < 0.05). A high threshold of decompensated metabolic acidosis and VO2peak were related to a fast overall time (r = -0.70 to -0.72, P < 0.05) and high running speed (r = 0.64 to 0.79, P < 0.05 and P < 0.01, respectively), and were thus the best predictors of performance.     

Estimation of thigh muscle and adipose tissue volume using magnetic resonance imaging and anthropometry

Thigh muscle volume is a useful determinant of functional fitness. However, anthropometric prediction of muscle content is influenced by the variability of adipose tissue accumulation. The aims of this study were to predict thigh muscle and adipose tissue volumes from anthropometry and to assess the validity of the method by examining the various components of the measurements and the assumptions involved. The 19 participants (9 men, 10 women; age 23-49 years) varied in adiposity. They all underwent magnetic resonance imaging (MRI) of the upper leg and the eight men and two women with the lowest adiposity underwent detailed anthropometry involving girths and skinfolds. Using MRI as the reference method, muscle volume was predictedfrom anthropometry using a circular concentric model, and the assumptions inherent in the method were tested further using the MRI data alone. Muscle volume was best predicted by anthropometry in the 10 leanest participants using a five-slice truncated cone model that overestimated the mean MRI value by 30% (R2 = 0.95; standard error of estimate = 288 cm3; P < 0.001). A single skinfold plus girth measurement at the mid-thigh almost matched its predictive ability, but with an increased bias. Measurements of leg circumference by means of the two techniques agreed well. The assumption of a circular cross-section was valid. In contrast, the agreement between skinfold thickness measured by caliper and superficial adipose tissue thickness by MRI was poor, contributing to the scatter of fat and lean area comparisons. An anterior skinfold thickness measurement underestimated the area of superficial adipose tissue at that level, particularly at the most proximal and distal sites. Although these limitations increase the uncertainties of muscle volume determination by anthropometry, they do not prevent its valid prediction in leaner individuals. The prediction of superficial adipose tissue was poorer.     

Comparison between the force application point determined by portable force plate system and the center of pressure determined by pressure insole system during alpine skiing

The purposes of this study were (1) to compare the force application point (FAP) calculated by a portable force plate system and the center of pressure (COP) calculated by a pressure insole system during alpine skiing, and (2) to assess whether any statistical differences between FAP/COP characteristics were influenced by the skiing modes, skiers’ skill levels, or pitch of the slope. Seven expert and eight intermediate skiers performed 20 double turns with two different skiing techniques. Similarities between the time characteristics of both systems and repeated measures ANOVA were used for the statistical analysis. Time characteristics of both systems in the y direction (anterior–posterior) were highly comparable. The mean FAP and COP in the x direction (medial–lateral) were different in all skiing modes for the outer ski and for the inner ski for the expert skiers. The ranges of the FAP in both directions were greater than the COP in almost all conditions.     

‘To honor and glorify God’: the role of religion in one intercollegiate athletics culture

Numerous events have provided evidence that the cultural values and assumptions of intercollegiate athletic departments are often incongruent with those of their host institutions. This discrepancy has even been evident in Christian institutions which seek to integrate faith into the learning experience. Using the organizational culture perspective, this study sought to determine how religion influenced the culture of one intercollegiate athletics department. The study took place at a highly selective evangelical Christian college with a nationally competitive athletic department. Data were collected through interviews with 19 campus leaders, observation of cultural events and document analysis. Analysis occurred qualitatively through a process of theorizing. The results indicate that evangelical Christianity played a significant role in the athletic department's culture by constraining its membership, influencing its pedagogy and guiding department decisions. As a result, its values and assumptions were consistent with those of the overall campus culture. The reasons underlying this cultural integration offer coaches and administrators of all institutional affiliations the possibility that the organizational culture perspective can be used to create athletic programs that are more consistent with institutional values.     

A response to David Kirk: personal/professional views from US authors

This paper represents the views of two scholars in the USA with respect to the scholar lecture presented by David Kirk at the 2012 BERA – Physical Education and Sport Pedagogy (PESP) Special Interest Group meeting. We discuss how two unique features of the American universities have an impact on both the corporate nature of our work and our scholarship. These features are described as ‘the notion of outreach scholarship’ and the ‘nature of giving.’ In addition, we discuss our different situations and how they affect our ability to do the best academic work. We can, and by consequence, give our best efforts to resist the hegemony of corporatization.     

Confirmatory factor analysis of the Test of Performance Strategies (TOPS) among adolescent athletes

The aim of the present study was to examine the factorial validity of the Test of Performance Strategies (TOPS; Thomas et al., ) among adolescent athletes using confirmatory factor analysis. The TOPS was designed to assess eight psychological strategies used in competition (i.e. activation, automaticity, emotional control, goal-setting, imagery, negative thinking, relaxation and self-talk,) and eight used in practice (the same strategies except negative thinking is replaced by attentional control). National-level athletes (n?=?584) completed the 64-item TOPS during training camps. Fit indices provided partial support for the overall measurement model for the competition items (robust comparative fit index?=?0.92, Tucker-Lewis index?=?0.88, root mean square error of approximation?=?0.05) but minimal support for the training items (robust comparative fit index?=?0.86, Tucker-Lewis index?=?0.81, root mean square error of approximation?=?0.06). For the competition items, the automaticity, goal-setting, relaxation and self-talk scales showed good fit, whereas the activation, emotional control, imagery and negative thinking scales did not. For the practice items, the attentional control, emotional control, goal-setting, imagery and self-talk scales showed good fit, whereas the activation, automaticity and relaxation scales did not. Overall, it appears that the factorial validity of the TOPS for use with adolescents is questionable at present and further development is required.     

Effect of sand versus grass training surfaces during an 8-week pre-season conditioning programme in team sport athletes

Abstract

This study compared the use of sand and grass training surfaces throughout an 8-week conditioning programme in well-trained female team sport athletes (n = 24). Performance testing was conducted pre- and post-training and included measures of leg strength and balance, vertical jump, agility, 20 m speed, repeat speed (8 × 20 m every 20 s), as well as running economy and maximal oxygen consumption (VO_2max). Heart rate (HR), training load (rating of perceived exertion (RPE) × duration), movement patterns and perceptual measures were monitored throughout each training session. Participants completed 2 × 1 h conditioning sessions per week on sand (SAND) or grass (GRASS) surfaces, incorporating interval training, sprint and agility drills, and small-sided games. Results showed a significantly higher (P < 0.05) HR and training load in the SAND versus GRASS group throughout each week of training, plus some moderate effect sizes to suggest lower perceptual ratings of soreness and fatigue on SAND. Significantly greater (P < 0.05) improvements in VO_2max were measured for SAND compared to GRASS. These results suggest that substituting sand for grass training surfaces throughout an 8-week conditioning programme can significantly increase the relative exercise intensity and training load, subsequently leading to superior improvements in aerobic fitness.