Parallel assessment of nutrition and activity in athletes: Validation against doubly labelled water, 24-h urea excretion,and indirect calorimetry

Abstract

The assessment of nutrition and activity in athletes requires accurate and precise methods. The aim of this study was to validate a protocol for parallel assessment of diet and exercise against doubly labelled water, 24-h urea excretion, and respiratory gas exchange. The participants were 14 male triathletes under normal training conditions. Energy intake and doubly labelled water were weakly associated with each other (r = 0.69, standard error of estimate [SEE] = 304 kcal · day^?1). Protein intake was strongly correlated with 24-h urea (r = 0.89) but showed considerable individual variation (SEE = 0.34 g · kg^?1 · day^?1). Total energy expenditure based on recorded activities was highly correlated with doubly labelled water (r = 0.95, SEE = 195 kcal · day^?1) but was proportionally biased. During running and cycling, estimated exercise energy expenditure was highly correlated with gas exchange (running: r = 0.89, SEE = 1.6 kcal · min^?1; cycling: r = 0.95, SEE = 1.4 kcal · min^?1). High exercise energy expenditure was slightly underestimated during running. For nutrition data, variations appear too large for precise measurements in individual athletes, which is a common problem of dietary assessment methods. Despite the high correlations of total energy expenditure and exercise energy expenditure with reference methods, a correction for systematic errors is necessary for the valid estimation of energetic requirements in individual athletes.     

Walking for health in pregnancy: assessment by indirect calorimetry and accelerometry

The purpose of this study was to examine RT3 accelerometer activity counts and activity energy expenditure of 36 pregnant women at 20 and 32 weeks' gestation during treadmill walking and free-living conditions. During treadmill walking, oxygen consumption was collected, and activity energy expenditure was estimated for a 30-min walk at a self-selected walking pace. The number of min it would take a pregnant woman to meet exercise recommendations (i.e., kcal/week) were calculated. Preliminary activity count cut points at a self-selected walking pace were then estimated and applied in interpreting free-living data. For the treadmill walking condition, the self-selected walking pace significantly decreased from 20 to 32 weeks' gestation. Additionally, few women (< 12% each day) met physical activity guidelines in the free-living condition. Encouraging pregnant women to walk for 30-40 min per day at a self-selected walking pace may be an appropriate public health recommendation.     

Measuring physical activity in field studies: Comparison of a questionnaire, 24-hour recall and an accelerometer

Abstract

In a field setting, we compared a physical activity questionnaire (SQUASH), a 24-hour recall measure (Physical Activity Scale; PAS), and an accelerometer to: (1) quantify the amount of time spent in light, moderate, and vigorous physical activity; (2) calculate activity scores; and (3) categorize participants by physical activity tertiles. For 7 consecutive days, 103 participants (61% males, 39% females; mean age 36.8 years, mean body mass index 26.6 kg·m^?2) wore an accelerometer and completed the PAS. Immediately before these 7 days, the participants completed the SQUASH and underwent anthropometric measurements (weight and height). Time spent in light (<3 METs), moderate (3–6 METs), and vigorous (≥6 METs) activity was calculated. Significant correlations were observed between the PAS and accelerometer in the population as a whole (r=0.66, P<0.001), the males (r=0.76, P<0.001), participants of normal weight (r=0.62, P<0.05), and those who were overweight (r=0.53, P<0.01). Correlations between the SQUASH and accelerometer were only significant for males (r=0.62, P<0.05) and overweight individuals (r=0.40, P<0.05). Moderate agreement was observed between tertiles for the accelerometer and PAS activity scores in the overall population (weighted kappa =0.47; 95% confidence interval =0.27–0.67) but not between the accelerometer and SQUASH. In conclusion, a 7-day administration of the PAS is a useful measure for classification of physical activity in the population studied. The SQUASH has practical advantages in terms of convenience of administration, but its usefulness in estimating physical activity is limited.     

Assessment of physical activity with the Computer Science and Applications, Inc., accelerometer: laboratory versus field validation

Our purpose was to compare the validity of the Computer Science and Applications, (CSA) Inc., accelerometer in laboratory and field settings and establish CSA count ranges for light, moderate, and vigorous physical activity. Validity was determined in 60 adults during treadmill exercise, using oxygen consumption (VO2) as the criterion measure, while 30 adults walked and jogged outdoors on a 400-m track. The relationship between CSA counts and VO2 was linear (R2 = .89 SEE = 3.72 ml.kg-1.min-1), as was the relationship between velocity and counts in the field (R2 = .89, SEE = 0.89 mi.hr-1). However, significant differences were found (p < .05) between laboratory and field measures of CSA counts for light and vigorous intensity. We conclude that the CSA can be used to quantify walking and jogging outdoors on level ground; however, laboratory equations may not be appropriate for use in field settings, particularly for light and vigorous activity.     

Assessment of total body water and its compartments in elite judo athletes: comparison of bioelectrical impedance spectroscopy with dilution techniques

Bioelectrical impedance spectroscopy (BIS) is an inexpensive and non-invasive technique to measure total body water (TBW), extracellular water (ECW), and intracellular water (ICW). The purpose of this study was to validate TBW, ECW and ICW assessed by BIS, using dilution techniques as the reference method (REF) in elite judo athletes. Thirty-two Portuguese elite male judo athletes were evaluated during a period of weight stability. TBW, ECW and ICW were assessed by BIS (Xitron 4000). Deuterium and bromide dilution techniques were used as the criterion method for measuring TBW and ECW, while ICW was calculated as the difference between the two. BIS explained 96%, 77% and 94% of the total variability from REFs for TBW, ECW and ICW, respectively. BIS also demonstrated high precision (ρ ≥ 0.88) and accuracy (C_b = 0.98), with a minimum concordance coefficient correlation of 0.87 for ECW. The mean bias demonstrated that BIS slightly overestimated the REF in 1.1 kg (2.3%), 0.3 kg (1.6%) and 0.8 kg (2.7%) for TBW, ECW and ICW, respectively. The 95% limits of agreement ranged from ?1.2 to 3.3 kg in TBW, from ?1.8 to 2.4 kg in ECW and from ?1.0 to 2.6 kg in ICW. A non-significant trend was found between the difference and the mean of reference and alternative methods. These findings highlight the efficacy of BIS as a valid non-biased tool for the assessment of TBW and its compartments in elite male judo athletes, during a period of weight stability.     

Eating disorders in athletes: Overview of prevalence,risk factors and recommendations for prevention and treatment

Abstract

The prevalence of disordered eating and eating disorders vary from 0–19% in male athletes and 6–45% in female athletes. The objective of this paper is to present an overview of eating disorders in adolescent and adult athletes including: (1) prevalence data; (2) suggested sport- and gender-specific risk factors and (3) importance of early detection, management and prevention of eating disorders. Additionally, this paper presents suggestions for future research which includes: (1) the need for knowledge regarding possible gender-specific risk factors and sport- and gender-specific prevention programmes for eating disorders in sports; (2) suggestions for long-term follow-up for female and male athletes with eating disorders and (3) exploration of a possible male athlete triad.     

When professional athletes change sports: Sport development,sanctity of contract,and restraint of trade in the NRL

This case study provides insight into a current issue faced by sporting leagues—the movement of professional players to different sports. As the case illustrates, the movement of professional players across sport codes can have a profound impact on the management of sport development, the management of player contracts, and legal issues in restraint of trade.     

Insights into the epidemiology,aetiology and associations of infraspinatus atrophy in overhead athletes: a systematic review

Infraspinatus atrophy (IA) is much more prevalent in overhead sports compared with the general population. Its exact aetiology in this group of athletes remains unclear and definitive associations with pathology and performance have not yet been reached. The aim of this systematic review is to present the evidence on IA in overhead athletes focussing on the proposed mechanisms of suprascapular neuropathy and its associations with shoulder pathology and performance. A thorough literature search via Medline, EMBASE and Scopus was performed. From the nine articles identified, the majority of authors propose suprascapular nerve (SN) injury at the spinoglenoid notch; however, the suprascapular notch has also been suggested as a potential site of injury. With regard to the exact mechanism of suprascapular neuropathy, the majority of authors propose repeated traction of the nerve during extreme shoulder abduction and horizontal adduction and/or eccentric contractions of the infraspinatus. In the limited relevant literature, convincing links between IA and performance or shoulder pathology have not been identified. IA in overhead sports is most likely of multi-factorial aetiology. Important questions about IA and its significance in overhead sports remain unanswered and more biomechanical and prospective studies are warranted to provide further insights into this athletic injury.     

Women athletes emerging from the shadow of men in Kenya: evidence from the Commonwealth,Olympic and World Athletics Championships

The academic interest in women’s roles in sports in Kenya reflects the concern to level the playing field in a major social cultural phenomenon such as sport and its overall significance to social development. It is therefore not surprising that, in Kenya, women were late in establishing themselves in the sporting world. Under-representation of females in sport within the African set-up, Kenya included, is attributed to the inappropriate western-oriented games, the conflicting values of sexual beauty and sporting competence, and the divorce between women and the warrior tradition of indigenous Africa. However, as data on Kenya’s athletes to various international events demonstrate, women have slowly but steadily emerged out of the shadows of men. In some editions of the games, women have not only been the majority, but also have won more medals than men.     

Promoting physical activity in a socially and economically deprived community: a 12 month randomized control trial of fitness assessment and exercise consultation

The main aim of this study was to assess the effects of a fitness assessment and exercise consultation on physical activity over 1 year in non-regularly active participants drawn from a socially and economically deprived community. Of 3000 people invited to volunteer for either intervention, 225 fitness assessment volunteers were randomly assigned to an experimental or control group; 145 exercise consultation volunteers were similarly assigned. Physical activity was measured at baseline, 4 weeks, 3 months (plus an intervention re-test), 6 months and 1 year. Analysis of variance and follow-up Bonferroni analysis showed that, for those not regularly active at baseline, physical activity increased significantly to 4 weeks, was maintained to 6 months but had fallen by 1 year. Only those receiving an exercise consultation significantly increased their physical activity after 1 year. Compared with fitness assessments, chi-square analysis showed that significantly more non-regularly active participants volunteered for an exercise consultation and those receiving an exercise consultation had significantly better long-term study adherence than those receiving a fitness assessment. The study also showed that, contrary to popular opinion, those in a socially and economically deprived community are not 'hard to reach' and respond well to physical activity interventions.     

Promoting physical activity in a socially and economically deprived community: a 12 month randomized control trial of fitness assessment and exercise consultation

The main aim of this study was to assess the effects of a fitness assessment and exercise consultation on physical activity over 1 year in non-regularly active participants drawn from a socially and economically deprived community. Of 3000 people invited to volunteer for either intervention, 225 fitness assessment volunteers were randomly assigned to an experimental or control group; 145 exercise consultation volunteers were similarly assigned. Physical activity was measured at baseline, 4 weeks, 3 months (plus an intervention re-test), 6 months and 1 year. Analysis of variance and follow-up Bonferroni analysis showed that, for those not regularly active at baseline, physical activity increased significantly to 4 weeks, was maintained to 6 months but had fallen by 1 year. Only those receiving an exercise consultation significantly increased their physical activity after 1 year. Compared with fitness assessments, chi-square analysis showed that significantly more non-regularly active participants volunteered for an exercise consultation and those receiving an exercise consultation had significantly better long-term study adherence than those receiving a fitness assessment. The study also showed that, contrary to popular opinion, those in a socially and economically deprived community are not 'hard to reach' and respond well to physical activity interventions.     

Monitoring health,activity and fitness in physical education: its current and future state of health

Various government policies, strategies and responses in England over the years have highlighted schools and physical education to be instrumental in addressing health and the focus on health has been strengthened within subsequent revisions of the National Curriculum. Whilst this might seem encouraging, concerns have been expressed that such policies and governmental regulation increasingly bear features of a ‘performative culture’ and that these have led to increasingly widespread health surveillance in schools. Linked to this are long-standing concerns over the way in which health is addressed in schools and physical education, as well as over some of the monitoring measures and practices employed within the curriculum. Despite this, little is known about monitoring practices in physical education. This article, therefore, presents findings of a study which aimed to (1) determine the nature, prevalence and purpose of monitoring health, physical activity and physical fitness within the physical education curriculum and (2) establish physical education teachers' views of and approaches to monitoring. The study comprised two phases. The first phase involved a survey completed by Heads of Physical Education in 110 secondary schools from across England, and the second semi-structured interviews with 18 of those from the original sample. The findings revealed monitoring, and in particular fitness monitoring, to be a common feature within the physical education curriculum in many schools. However, a number of issues and limitations associated with monitoring and some of the schools' monitoring practices were identified, and the individualistic nature and performative culture reflected in and reinforced through monitoring were acknowledged as potentially problematic. It was thus suggested that if the findings are typical, then monitoring practice is currently not in a good state of health. The article concludes proposing a way forward for monitoring within physical education in the form of some recommendations for practice.     

Sensor-based physical activity,sedentary time,and reported cell phone screen time: A hierarchy of correlates in youth

BackgroundEvidence on correlates relies on subjective metrics and fails to include correlates across all levels of the ecologic model. We determined which correlates best predict sensor-based physical activity (PA), sedentary time (ST), and self-reported cell phone screen time (CST) in a large sample of youth, while considering a multiplicity of correlates.MethodsUsing sensor-based accelerometry, we assessed the PA and ST of 2179 youths. A χ² automatic interaction detection algorithm was used to hierarchize the correlates associated with too much ST (> 50th percentile), insufficient moderate-to-vigorous PA (MVPA) (<60 min/day), and prolonged CST (≥2 h/day).ResultsAmong youth 10–14 years old, the correlates for being inactive consisted of being a girl, not having sport facilities in the neighborhood, and not perceiving the neighborhood as a safe place, whereas in the youth 15–18 years old, the correlate for being inactive was not performing sports (9.7% chance of being active). The correlates for predicting high ST in the younger group was not performing sports (55.8% chance for high ST), and in the older group, the correlates were not owning a pet, perceiving the neighborhood as safe, and having inactive parents (63.7% chance for high ST). In the younger group, the greatest chances of having high CST were among those who were in the last elementary school years, who were girls, and who did not have friends in the neighborhood (73.1% chance for high CST), whereas in the older group, the greatest chance for having high CST was among those who were girls and had a TV in the bedroom (74.3% chance for high CST).ConclusionTo counteract ST and boost MVPA among youths, a specific focus on girls, the promotion of sport participation and facilities, neighborhood safety, and involvement of family must be prioritized.     

Social physique anxiety experiences in physical activity: a comprehensive synthesis of research studies focused on measurement,theory, and predictors and outcomes

Physical activity (PA) settings such as sport, exercise, and physical education are inherently social and evaluative in nature, with much attention directed at how the body looks and performs. As such, these settings foster a host of positive and negative emotional experiences. Social physique anxiety (SPA) is a commonly studied emotion that emanates from, or motivates, PA behaviors. In this synthesis of the 126 identified research papers focused on SPA and related experiences in sport, exercise, and physical education, we summarize the theoretical roots and measurement of SPA, present research evidence on predictors and outcomes of SPA experiences, explore links between SPA and PA behaviors, and offer insight on the future directions of SPA research. Specifically, researchers in sport and exercise psychology are encouraged to broaden the study of SPA to conduct longitudinal and experimental studies, develop quality intervention strategies aimed at reducing SPA experiences, and expand on the theoretical and operational understandings of SPA experiences across the lifespan.     

Moving fast,thinking fast: The relations of physical activity levels and bouts to neuroelectric indices of inhibitory control in preadolescents

BackgroundStructured vigorous physical activity (VPA) can improve cognitive control in children, but studies relating daily physical activity (PA) to cognitive control have yielded conflicting findings. While objectively measured daily PA summarizes all occurrences of PA within a registered period, a minimum duration of continuous PA is required for registration of a PA bout. Because brief bouts of high-intensity PA can account for a large proportion of children's daily activity-related energy expenditure, this study assessed whether daily and bouted VPA were selectively related to cognitive control in preadolescents relative to other PA intensities.MethodsA total of 75 children between the ages of 8 and 10 years (49% girls) wore an ActiGraph wGT3X+ on the hip for 7 days. The acceleration signal from the vertical axis was summarized over 1 s, 5 s, and 15 s epochs. Daily and bouted moderate PA, moderate-to-vigorous PA, and VPA were measured. PA bouts were expressed as the frequency and time spent in 2 different continuous PA bouts, one lasting ≥10 s and the other lasting ≥30 s at a given intensity. Inhibitory control was assessed using behavioral responses to a modified flanker task (mean reaction time (RT_mean) and accuracy). Attentional resource allocation and cognitive processing speed were measured using the amplitude and latency of the P3 component of event-related brain potentials, respectively. Associations between PA, behavioral indices of inhibitory control, P3 amplitude, and latency were assessed using hierarchical regression models.ResultsDaily VPA was not related to RT_mean or accuracy on either congruent or incongruent trials. In contrast, more time spent in VPA bouts lasting ≥30 s predicted shorter P3 latency across epochs and flanker congruencies (all β ≤ –0.24, all p ≤ 0.04). The associations between shorter P3 latency and the time spent in moderate-to-vigorous PA bouts lasting ≥30 s were less consistent and largely limited to congruent trials (congruent: β (–0.31, –0.34)). No significant associations were observed upon correction for false discovery rate.ConclusionThe pattern of uncorrected associations aligns with the dose–response literature and suggests that brief VPA bouts may yield the greatest benefits to cognitive processing speed in preadolescents. Future studies using measures of brain structure and function are needed to understand the mechanisms linking bouted VPA to neurocognitive function during childhood.     

Associations of total sedentary time,screen time and non-screen sedentary time with adiposity and physical fitness in youth: the mediating effect of physical activity

The aims of the present study were: i) to examine the associations of total accelerometer-based sedentary time (ST) and specific-domain self-reported ST (i.e., screen-based, educational-based, social-based, and other-based ST) with adiposity and physical fitness in youth; and ii) to analyse the mediation effect of physical activity (PA) on associations.

This study was conducted with 415 children (9.1 ± 0.4 years) and 853 adolescents (13.6 ± 1.6 years) in Spain during 2011–2012. Total ST and PA were assessed by accelerometry. Leisure-time spent in twelve sedentary behaviours was self-reported. Adiposity and physical fitness was measured following the ALPHA battery for youth.

Total accelerometer-based ST was positively associated with global adiposity score in children, and negatively associated with global physical fitness score in children and adolescents; but relationships were not independent of PA. PA mediated all associations of accelerometer-based and self-reported ST with adiposity or physical fitness in children. Conversely, screen-, educational-, social-, and other-based ST were negatively related to physical fitness in adolescents, independently of PA.

These findings give an impetus to developing effective strategies for specifically promoting PA in children and for increasing PA while reducing ST in adolescents in order to produce improvements on adiposity and physical fitness.     

Mediating effect of aerobic fitness on the association between physical activity and academic achievement among adolescents: A cross-sectional study in Okinawa,Japan

The purpose of this study was to examine the potential role of aerobic fitness (AF) as a mediator of the association between physical activity (PA) and academic achievement (AA) among Japanese junior high school students. A cross-sectional data was collected from 608 7th grade students enrolled at five public junior high schools in two suburban municipalities in Okinawa, Japan. Self-reported PA was assessed using the Patient-Centred Assessment and Counselling for Exercise plus Nutrition questionnaire. The 20-meter shuttle run test was performed to determine AF. AA was evaluated using the overall grade point average. Family structure, parental education level, and achievement motives were the self-reported covariates. The results of the bootstrapped mediation analysis indicated that PA had a direct effect on AF, which in turn influenced the AA among boys. After adjusting for AF, the association between PA and AA disappeared while the association of AF with AA still remained. However, neither PA nor AF was associated with the AA of girls. Therefore, the hypothesis that AF might mediate the relationship between PA and AA was supported for boys. Promoting AF, as a result of engaging to PA could positively influence AA particularly in boys.