The Diet Quality of Competitive Adolescent Male Rugby Union Players with Energy Balance Estimated Using Different Physical Activity Coefficients

Contemporary Themes in Dietary Intake in Rugby Union Players: A Narrative Review

Rugby union is an intermittent team sport with variability in body composition and match-play demands between positions which requires careful consideration for individual dietary requirements. While previous reviews have detailed the macronutrient intake in rugby players, none have discussed the further determinants of dietary intake in this population. Therefore, the purpose of the current review was to summarise the current evidence detailing dietary intake in rugby union players, report on contemporary nutritional research themes, and provide recommendations for athletes, nutritionists, and other stakeholders. In total, eighteen articles report on dietary intake in rugby players, with only one of these detailing dietary intake in female athletes. Recent studies have reported on both protein and carbohydrate periodisation practices in rugby union players; however, there is currently limited evidence as to the influence of these on performance, recovery, and well-being. Factors influencing eating patterns, the impact of sports nutritionists on dietary intake, and food consumption in catered and non-catered environments has been explored in isolated studies. Nutrition knowledge levels in rugby players have been reported in several studies; however, the influence this has on dietary intake in rugby players is unknown. Collectively, despite new contemporary themes emerging in the literature concerning dietary intake in rugby players, the studies are isolated; as such, there is limited scope to the translatability of information due to heterogeneity in sex, level of play, and location of participants. Given this, future research should aim to build upon the themes identified in this review in combination to support practitioners working within their specific environments. This will subsequently build towards the generation of rugby-specific recommendations.

Energy Balance and Dietary Intake in Young Rugby Players during a Pre-Season Micro-Cycle: A Cluster Analysis

Rugby players must develop excellent levels of conditioning during adolescence. However, this pivotal period of life is also characterized by a surge in biological growth, which further increases the energy and nutritional requirements of this population. This study examined within-individual differences in energy intake (EI) and energy balance (EB) of 46 young rugby players during a pre-season micro-cycle. Two clusters were identified with significantly different characteristics and EB states, suggesting that young rugby players adjust their EI to match their body composition goals. The first cluster is characterized by players with a low body fat% (12.87 ± 2.53). They had a positive EB (330 ± 517 kcal), suggesting a goal of increasing muscle mass. Conversely, the second cluster is characterized by a higher body fat% (23.1 ± 1.6, p < 0.005) and reported a negative, lower EB (-683 ± 425 kcal, p < 0.005), suggesting a goal focused on reducing fat mass. Although our study provides more optimistic results than previous ones regarding the high risk of inadequate EI in young rugby players, we emphasize the importance of rigorous nutritional support, especially for players aiming to lose weight, to avoid severe caloric restriction, as well as the downstream effects of such practices on their nutritional status, given the higher risk of macro- (e.g., CHO < 6 g/kg/d) and micronutrient (e.g., iron < 11 mg/d, calcium < 1300 mg/d, vitamin D < 5 mg/d) deficiencies.

Nutrition for Children and Adolescents Who Practice Sport: A Narrative Review

At a developmental age, adequate physical activity is fundamental to overall health and well-being and preventing obesity. Moreover, establishing active behavior can help children and adolescents meet their growth and neurodevelopmental goals. Nutritional requirements vary according to intensity, frequency, and practiced physical activity or sport; therefore, pediatricians should give children and adolescents and their families adequate counseling, avoiding both nutrient deficiencies and excessive or inadequate supplement intake. The focus should be not only on sports performance but also on the child's well-being, growth, and neurodevelopment. Our narrative review aims to discuss the nutritional needs of children and adolescents who practice physical activity, non-competitive sports activity, and elite sports activity while also analyzing the role of food supplements and the risk of eating disorders within this category of subjects.

Adolescent athletes have better general than sports nutrition knowledge and lack awareness of supplement recommendations: a systematic literature review

Nutrition knowledge (NK) impacts food choices and may be improved through educational programmes. Identifying knowledge gaps related to NK among adolescent athletes may guide future nutrition education programmes. This review aimed to systematically review the level of NK in adolescent athletes based on the currently available published literature. The protocol for this review was registered with PROSPERO (CRD42022321765). A literature search was conducted in April 2022 using MEDLINE, CINAHL, SPORTDiscus, Web of Science and SCOPUS databases. The study design was not restricted, provided that a quantitative NK score was reported for adolescent athletes. Studies were limited to the English language and published between 2010 and April 2022. Studies were assessed for quality and risk of bias using the Academy of Nutrition and Dietetics Quality Appraisal Checklist. Data extracted included demographics, questionnaire name, number of items, validation status and mean total and subsection NK scores. Meta-analyses were inappropriate due to the heterogeneity of NK assessment tools; therefore, results were presented narratively. Thirty-two studies that assessed NK of 4553 adolescent athletes and 574 comparison participants were included. Critical appraisal of studies resulted in neutral rating 'moderate quality' for most (n 30) studies. Studies lacked justification for sample size and often used inadequately validated questionnaires. NK scores ranged from poor (33·3 %) to excellent (90·6 %). The level of NK across studies is difficult to determine due to heterogenous questionnaires often lacking appropriate validation. NK should be assessed using tools validated in the relevant population or revalidated tools previously used for other populations.

Association between Low Energy Availability (LEA) and Impaired Sleep Quality in Young Rugby Players

Low energy availability (LEA) has been associated with several physiological consequences, but its impact on sleep has not been sufficiently investigated, especially in the context of young athletes. This study examined the potential association between energy availability (EA) status and objective sleep quality in 42 male rugby players (mean age: 16.2 ± 0.8 years) during a 7-day follow-up with fixed sleep schedules in the midst of an intensive training phase. Participants' energy intake was weighed and recorded. Exercise expenditure was estimated using accelerometry. Portable polysomnography devices captured sleep on the last night of the follow-up. Mean EA was 29.3 ± 9.14 kcal·kg FFM-1·day-1, with 47.6% of athletes presenting LEA, 35.7% Reduced Energy Availability (REA), and 16.7% Optimal Energy Availability (OEA). Lower sleep efficiency (SE) and N3 stage proportion, along with higher wake after sleep onset (WASO), were found in participants with LEA compared to those with OEA (p = 0.04, p = 0.03 and p = 0.005, respectively, with large effect sizes). Segmented regression models of the EA-sleep outcomes (SE, sleep onset latency [SOL]), WASO and N3) relationships displayed two separate linear regions and produced a best fit with a breakpoint between 21-33 kcal·kg FFM-1·day-1. Below these thresholds, sleep quality declines considerably. It is imperative for athletic administrators, nutritionists, and coaches to conscientiously consider the potential impact of LEA on young athletes' sleep, especially during periods of heavy training.

Investigating Nutrition and Hydration Knowledge and Practice among a Cohort of Age-Grade Rugby Union Players

Optimal athletic performance relies on meeting specific nutritional requirements, encompassing adequate calorie intake, macronutrient intake, and hydration. Misinformation or misconceptions about these necessities are prevalent among young athletes. This study investigated nutrition and hydration knowledge and practices among 28 male rugby union players aged 16 to 17, participating in Munster Rugby's 2023 Summer Age-Grade Development Programme, specifically the U18's Schools Squad. The Nutrition for Sport Knowledge Questionnaire assessed nutrition knowledge, while the Hydration Assessment Questionnaire evaluated hydration knowledge. Urinalysis for hydration status utilised urine specific gravity measurements pre-exercise on five separate days (1.018 ± 0.008 Usg). Dietary intake was recorded using a 3-day estimated food intake record on the Libro App, analysed with Nutritics software(Version 9.50). Suboptimal nutrition knowledge (49.6 ± 8.2%) and dietary practices were observed, with incongruent nutrient intakes compared to recommendations for adolescent athletes. While superior hydration knowledge (79.0 (77.3, 83.6) %) was evident, pre-exercise urine specific gravity readings indicated significant variation (p < 0.001) and signs of dehydration (USG > 1.020 Usg). No statistically significant correlations were found between knowledge and practices. The study highlights suboptimal nutrition and hydration knowledge and practices in youth athletes, suggesting the need for tailored support and educational interventions to enhance their overall health and performance. Further investigation into barriers and facilitators to dietary adherence is recommended for more effective interventions.

Development of an Athlete Diet Index for Rapid Dietary Assessment of Athletes

Food-based diet indices provide a practical, rapid, and inexpensive way of evaluating dietary intake. Rather than nutrients, diet indices assess the intake of whole foods and dietary patterns, and compare these with nutrition guidelines. An athlete-specific diet index would offer an efficient and practical way to assess the quality of athletes' diets, guide nutrition interventions, and focus sport nutrition support. This study describes the development and validation of an Athlete Diet Index (ADI). Item development was informed by a review of existing diet indices, relevant literature, and in-depth focus groups with 20 sports nutritionists (median of 11 years' professional experience) from four elite athlete sporting institutes. Focus group data were analyzed (NVivo 11 Pro; QSR International Pty. Ltd., 2017, Melbourne, Australia), and key themes were identified to guide the development of athlete-relevant items. A modified Delphi survey in a subgroup of sports nutritionists (n = 9) supported item content validation. Pilot testing with athletes (n = 15) subsequently informed face validity. The final ADI (n = 68 items) was categorized into three sections. Section A (n = 45 items) evaluated usual intake, special diets or intolerances, dietary habits, and culinary skills. Section B (n = 15 items) assessed training load, nutrition supporting training, and sports supplement use. Section C (n = 8 items) captured the demographic details, sporting type, and caliber. All of the athletes reported the ADI as easy (40%) or very easy (60% of participants) to use and rated the tool as relevant (37%) or very relevant (63% of participants) to athletes. Further evaluation of the ADI, including the development of a scoring matrix and validation compared with established dietary methodology, is warranted.

Pro-Healthy Diet Properties and Its Determinants among Aging Masters Athletes

Qualitative dietary assessments are not common in aging athletes. Therefore, this study aimed to evaluate diet quality and its determinants among aging masters athletes. Eighty-six participants of the 8th World Masters Indoor Athletics Championships were enrolled in the study (age range 36-65 years). Three subgroups were distinguished to represent countries with different eating habits. Body composition was measured by bioelectrical impedance. Eating habits and diet quality were assessed using the Dietary Habits and Nutrition Beliefs Questionnaire (KomPAN®, Warszawa, Poland), and the Pro-healthy Diet Index (pHDI-10). Dietary quality determinants were identified by a multiple regression model conducted for each subgroup separately (Great Britain, France, and Poland). The results showed that none of the subgroups adhered to the reference intake of products with beneficial health outcomes. This was particularly noticeable in the insufficient consumption of whole grain products, dairy, and fish. The fish and vegetables consumption frequency significantly differentiated the eating habits of the studied groups. Diet quality determinants varied depending on the group. However, in each of them, fruit consumption was one of the components of a good-quality diet. The obtained results can be used by institutions providing health education among the elderly to develop an appropriate strategy aimed at changing inappropriate eating habits.

Diet Quality of Elite Australian Athletes Evaluated Using the Athlete Diet Index

While athletes’ nutrient intakes have been widely reported, few studies have assessed the diet quality of athletes. This is the first study to evaluate the diet quality of athletes using the purpose-built Athlete Diet Index (ADI). A convenience sample of 165 elite athletes from Australian sporting institutions completed the ADI online, with subsequent automated results provided to their respective accredited sports dietitians (ASDs). At the completion of athlete participation, ASDs (n = 12) responded to a range of survey items using a Likert scale (i.e., 1 = strongly agree to 5 = strongly disagree) to determine the suitability of the ADI in practice. Differences in ADI scores for demographics and sport-specific variables were investigated using independent t-tests, analysis of variance (ANOVA) and Bonferroni multiple comparisons. Spearman’s rank correlation was used to assess the association between total scores and demographics. The mean total ADI score was 91.4 ± 12.2 (range 53–117, out of a possible 125). While there was no difference in total scores based on demographics or sport-specific variables; team sport athletes scored higher than individual sport athletes (92.7 vs. 88.5, p < 0.05). Athletes training fewer hours (i.e., 0–11 h/week) scored higher on Dietary Habits sub-scores compared with athletes training more hours (≥12 h/week; p < 0.05), suggesting that athletes who train longer may be at risk of a compromised dietary pattern or less than optimal nutrition practices that support training. Most (75%) ASDs surveyed strongly agreed with the perceived utility of the ADI for screening athletes and identifying areas for nutrition support, confirming its suitability for use in practice.

Relative validity and reliability of a novel diet quality assessment tool for athletes: the Athlete Diet Index

Diet quality indices are a practical, cost-effective method to evaluate dietary patterns, yet few have investigated diet quality in athletes. This study describes the relative validity and reliability of the recently developed Athlete Diet Index (ADI). Participants completed the electronic ADI on two occasions, 2 weeks apart, followed by a 4-d estimated food record (4-dFR). Relative validity was evaluated by directly comparing mean scores of the two administrations (mAdm) against scores derived from 4-dFR using Spearman's rank correlation coefficient and Bland-Altman (B-A) plots. Construct validity was investigated by comparing mAdm scores and 4-dFR-derived nutrient intakes using Spearman's coefficient and independent t test. Test-retest reliability was assessed using paired t test, intraclass correlation coefficients (ICC) and B-A plots. Sixty-eight elite athletes (18·8 (sd 4·2) years) from an Australian sporting institute completed the ADI on both occasions. Mean score was 84·1 (sd 15·2; range 42·5-114·0). The ADI had good reliability (ICC = 0·80, 95 % CI 0·69, 0·87; P < 0·001), and B-A plots (mean 1·9; level of agreement -17·8, 21·7) showed no indication of systematic bias (y = 4·57-0·03 × x) (95 % CI -0·2, 0·1; P = 0·70). Relative validity was evaluated in fifty athletes who completed all study phases. Comparison of mAdm scores with 4-dFR-derived scores was moderate (rs 0·69; P < 0·001) with no systematic bias between methods of measurement (y = 6·90-0·04 × x) (95 % CI -0·3, 0·2; P = 0·73). Higher scores were associated with higher absolute nutrient intake consistent with a healthy dietary pattern. The ADI is a reliable tool with moderate validity, demonstrating its potential for application to investigate the diet quality of athletes.

A Scoping Review of the Operationalization of Fruit and Vegetable Variety

Adequate consumption of fruits and vegetables is critical for healthy growth and development. Less is known about fruit and vegetable variety, with variation in operationalization of variety. This review aims to identify currently available evidence operationalizing fruit and vegetable (FV) variety through a scoping review to summarize, compare, and critically evaluate the operationalization of variety. A secondary aim is to examine the implications of measuring FV variety and outcomes including dietary quality/nutrient intake. PubMed, Medline, PsycINFO were searched using the following criteria: (1) human study participants ages 2 years and above; (2) assessment of fruit variety consumption, vegetable variety consumption, or combined fruit and vegetable variety consumption; and (3) peer-reviewed publication available in the English language. Etiologic, intervention, and determinant studies were eligible to be included, and 47 studies met inclusion criteria. Differences in operationalization of variety were found. Findings included associations of FV variety with aspects of nutrient intake, dietary behaviors, lifestyle behaviors, and health outcomes. There were no studies that assessed conventionally grown produce vs. organic produce, and none of the included studies assessed cultivar. Nonstandard classification of fruit and vegetables, differences in fruit and vegetables grown in other countries, and the restriction to studies published in the English language may have excluded studies examining variety published in languages other than English. Operationalization of variety should be reported to allow one to explore comparability across studies, use national or international guidelines for greater comparability, associate variety with nutrient intake, and change variety behaviors via intervention.

Reliability and validity of the physical activity monitor for assessing energy expenditures in sedentary, regularly exercising, non-endurance athlete, and endurance athlete adults

Background

Inertial sensors, such as accelerometers, serve as convenient devices to predict the energy expenditures (EEs) during physical activities by a predictive equation. Although the accuracy of estimate EEs especially matter to athletes receive physical training, most EE predictive equations adopted in accelerometers are based on the general population, not athletes. This study included the heart rate reserve (HRR) as a compensatory parameter for physical intensity and derived new equations customized for sedentary, regularly exercising, non-endurance athlete, and endurance athlete adults.

Methods

With indirect calorimetry as the criterion measure (CM), the EEs of participants on a treadmill were measured, and vector magnitudes (VM), as well as HRR, were simultaneously recorded by a waist-worn accelerometer with a heart rate monitor. Participants comprised a sedentary group (SG), an exercise-habit group (EHG), a non-endurance group (NEG), and an endurance group (EG), with 30 adults in each group.

Results

EE predictive equations were revised using linear regression with cross-validation on VM, HRR, and body mass (BM). The modified model demonstrates valid and reliable predictions across four populations (Pearson correlation coefficient, r: 0.922 to 0.932; intraclass correlation coefficient, ICC: 0.919 to 0.930).

Conclusion

Using accelerometers with a heart rate monitorcan accurately predict EEs of athletes and non-athletes with an optimized predictive equation integrating the VM, HRR, and BM parameters.

Diet Quality Is Associated with Physical Performance and Special Forces Selection

PURPOSE

This study determined associations between diet quality measured by the Healthy Eating Index (HEI)-2015, physical performance, and successful selection following a U.S. Army Special Forces Assessment and Selection course characterized by arduous cognitive and physical demands.

METHODS

The HEI-2015 scores were calculated from usual diet assessed with a Block food frequency questionnaire among 782 soldiers attending Special Forces Assessment and Selection. Differences in HEI-2015 scores according to demographics and physical performance were determined with analysis of variance. Differences in likelihood of selection according to HEI-2015 scores were determined with logistic regression. Models were adjusted for potential confounders: age, education, body mass index (BMI), duration and type of resistance training, and smoking.

RESULTS

The HEI-2015 total score was higher among older soldiers (≥25 yr), those with more education (≥some college), higher body mass index (≥25), longer duration of resistance training (≥400 min·wk), those that reported use of free weights, suspension training, Olympic lifting, and nonsmokers (P < 0.05). The HEI-2015 total score was higher among those with higher Army Physical Fitness Test (APFT) total scores, APFT sit-up score, APFT run score, and faster loaded road march times (P < 0.05). Those with higher HEI-2015 total scores were 75% (quartile 3 vs quartile 1: odds ratio, 1.75; 95% confidence interval, 1.09-2.81) and 65% (quartile 4 vs quartile 1: odds ratio, 1.65, 95% confidence interval, 1.03-2.65) more likely to be selected. Higher scores for total vegetables, greens and beans, seafood and plant protein, and refined grains, but lower sodium scores (indicating more sodium consumed), were associated with better physical performance (P < 0.05).

CONCLUSIONS

Dietary patterns that conform to federal dietary guidelines (except sodium) are associated with physical performance and Special Forces selection.

Testing methods and physical qualities of male age grade rugby union players: A systematic review

BACKGROUND

Rugby union match demands are complex, requiring the development of multiple physical qualities concurrently. Quantifying the physical qualities of age grade rugby union players is vital for practitioners to support athlete preparation and long-term development.

AIM

This systematic review aimed to identify the methods used to quantify the physical qualities of male age grade (≤ Under-20) rugby union players, present the normative values for physical qualities, and compare physical qualities between age grades and positions.

METHODS

Electronic databases were systematically reviewed from the earliest record to November 2019 using key words relating to sex, age, sport and physical testing.

RESULTS

Forty-two studies evaluated the physical qualities of age grade rugby union players. Seventy-five tests were used to quantify body composition, muscular strength, muscular power, linear speed, change of direction ability, aerobic capacity and anaerobic endurance. Thirty-one studies met the eligibility criteria to present the physical qualities. Physical qualities differentiate between age groups below Under-16, while differences in older age groups (Under-16 to Under-20) are not clear. Positional differences are present with forwards possessing greater height, body mass, body fat percentage and strength while backs are faster and have greater aerobic capacities.

CONCLUSIONS

A wide variety of tests are used to assess physical qualities limiting between study comparisons. Although differences in older age grades are unclear, older age groups (Under-19-20) generally performed better in physical tests. Positional differences are associated with match demands where forwards are exposed to less running but a greater number of collisions. Practitioners can use the results from this review to evaluate the physical qualities of age grade rugby union players to enhance training prescription, goal setting and player development. Future research should consider the use of national standardised testing batteries due to the inconsistency in testing methods and small samples limiting the reporting of positional differences.

Feasibility of the Energy Expenditure Prediction for Athletes and Non-Athletes from Ankle-Mounted Accelerometer and Heart Rate Monitor

Due to the nature of micro-electromechanical systems, the vector magnitude (VM) activity of accelerometers varies depending on the wearing position and does not identify different levels of physical fitness. Without an appropriate energy expenditure (EE) estimation equation, bias can occur in the estimated values. We aimed to amend the EE estimation equation using heart rate reserve (HRR) parameters as the correction factor, which could be applied to athletes and non-athletes who primarily use ankle-mounted devices. Indirect calorimetry was used as the criterion measure with an accelerometer (ankle-mounted) equipped with a heart rate monitor to synchronously measure the EE of 120 healthy adults on a treadmill in four groups. Compared with ankle-mounted accelerometer outputs, when the traditional equation was modified using linear regression by combining VM with body weight and/or HRR parameters (modified models: Model A, without HRR; Model B, with HRR), both Model A (r: 0.931 to 0.972; ICC: 0.913 to 0.954) and Model B (r: 0.933 to 0.975; ICC: 0.930 to 0.959) showed the valid and reliable predictive ability for the four groups. With respect to the simplest and most reasonable mode, Model A seems to be a good choice for predicting EE when using an ankle-mounted device.

Applied Sport Science for Male Age-Grade Rugby Union in England

Rugby union (RU) is a skill-collision team sport played at junior and senior levels worldwide. Within England, age-grade rugby governs the participation and talent development of youth players. The RU player development pathway has recently been questioned, regarding player performance and well-being, which sport science research can address. The purpose of this review was to summarise and critically appraise the literature in relation to the applied sport science of male age-grade RU players in England focussing upon (1) match-play characteristics, (2) training exposures, (3) physical qualities, (4) fatigue and recovery, (5) nutrition, (6) psychological challenges and development, and (7) injury. Current research evidence suggests that age, playing level and position influence the match-play characteristics of age-grade RU. Training exposures of players are described as 'organised chaos' due to the multiple environments and stakeholders involved in coordinating training schedules. Fatigue is apparent up to 72 h post match-play. Well-developed physical qualities are important for player development and injury risk reduction. The nutritional requirements are high due to the energetic costs of collisions. Concerns around the psychological characteristics have also been identified (e.g. perfectionism). Injury risk is an important consideration with prevention strategies available. This review highlights the important multi-disciplinary aspects of sport science for developing age-grade RU players for continued participation and player development. The review describes where some current practices may not be optimal, provides a framework to assist practitioners to effectively prepare age-grade players for the holistic demands of youth RU and considers areas for future research.

Determinants of coaches' intentions to provide different recommendations on sports nutrition to their athletes

BACKGROUND

Coaches are considered as an important source of nutrition information by their athletes. However, their knowledge in this area is often insufficient for proper guidance and may lead to the dissemination of misinformation regarding sports nutrition. The aim of this study was to assess coaches' intentions as well as psychosocial determinants underlying their intentions to provide sports nutrition recommendations to their high school athletes.

METHODS

Coaches (n = 47) completed a Web-based questionnaire based on the theory of planned behaviour, to assess their intentions to provide three different sports nutrition recommendations and their determinants. Multiple regression analyses were used to identify the variables that were most strongly related to the intentions.

RESULTS

Forty-six, 44.7 and 91.9% of coaches had the intention to recommend a higher consumption of foods rich in carbohydrates, foods rich in proteins and an increase in hydration to their athletes, respectively. Subjective norm was the only significant determinant of coaches' intention to recommend a higher consumption of foods rich in carbohydrates (R2 = 53.7%, β = 0.73 ± 0.12, P < 0.0001). Subjective norm and perceived behavioural control were significantly associated with coaches' intentions to recommend a higher consumption of foods rich in proteins (R2 = 25.9%, β = 0.50 ± 0.16, P = 0.002 and R2 = 17.2%, β = 0.39 ± 0.17, P = 0.01, respectively) and an increase in hydration (R2 = 26.8%, β = 0.38 ± 0.13, P = 0.001 and R2 = 46.3%, β = 0.58 ± 0.11, P < 0.0001, respectively).

CONCLUSIONS

The results of this study suggest that subjective norm and perceived behavioural control represent important determinants of coaches' intentions to provide recommendations on sports nutrition. These findings should be considered in future interventions aimed at facilitating proper general sports nutrition recommendations provided by coaches to their athletes.

Correction of estimation bias of predictive equations of energy expenditure based on wrist/waist-mounted accelerometers

Background

Using wearable inertial sensors to accurately estimate energy expenditure (EE) during an athletic training process is important. Due to the characteristics of inertial sensors, however, the positions in which they are worn can produce signals of different natures. To understand and solve this issue, this study used the heart rate reserve (HRR) as a compensation factor to modify the traditional empirical equation of the accelerometer EE sensor and examine the possibility of improving the estimation of energy expenditure for sensors worn in different positions.

Methods

Indirect calorimetry was used as the criterion measure (CM) to measure the EE of 90 healthy adults on a treadmill (five speeds: 4.8, 6.4, 8.0, 9.7, and 11.3 km/h). The measurement was simultaneously performed with the ActiGraph GT9X-Link (placed on the wrist and waist) with the Polar H10 Heart Rate Monitor.

Results

At the same exercise intensity, the EE measurements of the GT9X on the wrist and waist had significant differences from those of the CM (p < 0.05). By using multiple regression analysis—utilizing values from vector magnitudes (VM), body weight (BW) and HRR parameters—accuracy of EE estimation was greatly improved compared to traditional equation. Modified models explained a greater proportion of variance (R²) (wrist: 0.802; waist: 0.805) and demonstrated a good ICC (wrist: 0.863, waist: 0.889) compared to Freedson’s VM3 Combination equation (R²: wrist: 0.384, waist: 0.783; ICC: wrist: 0.073, waist: 0.868).

Conclusions

The EE estimation equation combining the VM of accelerometer measurements, BW and HRR greatly enhanced the accuracy of EE estimation based on data from accelerometers worn in different positions, particularly from those on the wrist.

Healthy eating promoting in a Brazilian sports-oriented school: a pilot study

BACKGROUND

Adolescents, particularly athletes, have high exposure to ultra-processed foods, which could be harmful to their health and physical performance. School environments are capable of improving eating patterns. Our study is aimed at capturing changes in students' food consumption three years after they enrolled at an experimental school, considered a model of health promotion in Rio de Janeiro city. We also aimed to depict the promising nature of the healthy eating promotion program implemented in the school and share the learnings from its implementation.

METHODS

Our pilot study was a follow-up on the implementation of a school garden, experimental kitchen activities, and health promotion classes. We evaluated 83 adolescent athletes' food consumption twice during the study: at its beginning (2013) and end (2016), by administering a food frequency questionnaire (FFQ) that inquired about the frequency of foods consumed in the past week. To evaluate how effectively the activities were established, integrated, and sustained in schools, the Garden Resources, Education, and Environment Nexus (GREEN) tool was used, and the school's adherence to the school garden program was classified as high (scored 47 points out of 57).

RESULTS

In 2013, 89 adolescents (mean ± SD 11.9 ± 0.4 years, 54% male) participated in the study, of which 83 continued until 2016 (14.8 ± 0.5 years, 55% male). In 2013, the mean frequency of raw salad and fruits consumption was 1.4 (CI [1.0-1.9]) and 4.3 (CI [3.8-4.9]) days per week, respectively. Three years later, the frequency of raw salad and fruits consumption was 2.2 (CI [1.6-2.7]) and 5.0 (4.5-5.5), respectively. Considering that five meals were offered at school (five days/week), it may be possible to assume that the program raised awareness on the importance of healthy eating.

CONCLUSION

Our results suggest that such integrated healthy eating promotion programs may improve adolescent athletes' eating habits, by increasing the frequency of their consumption of unprocessed foods. This pilot study's results inspired us to implement an expanded project at the municipal level. Since 2018, teachers who participated in this program are working with Rio de Janeiro's Municipal Secretary of Education for Coordination of Curricular Projects. Some learnings from this pilot study on implementing the garden/experimental kitchen project in this school are being applied in 65 schools of the municipal network: joint activities must be fostered among students, teachers, and parents; healthy eating needs to be a respected value among adolescent athletes and become an example for parents and teachers.

Macronutrient Intakes of Male Rugby Union Players: A Review

Rugby is a worldwide intermittent team sport. Players tend to be heavier than the majority of similar team sport athletes on whom the dietary guidelines have been developed. Therefore, the aim of the current review was to describe the intakes of rugby union players. Article databases were searched up to February 2017 and were included if they were published in English and reported dietary intakes of male rugby union players. Of the research articles identified, energy intakes were lower than two of three studies that reported intakes and expenditure, which would suggest the players were losing weight that is somewhat supported by the decreases in skinfolds seen during preseason. However, it should also be noted that there are errors in both the measurement of energy intakes and expenditure. Carbohydrate intakes ranged from 2.6 to 6.5 g·kg^-1·day^-1, which is lower than the current relative to body mass recommendations; however, this would not be classed as a low-carbohydrate diet. The consistently low intakes of carbohydrate suggest that these intake levels maybe sufficient for performance, given the players greater body mass or there are errors in the measurements. However, there is currently no evidence for the carbohydrate needs of rugby union players in terms of performance. The lower intakes than expenditure would suggest the players were losing weight. Previous research shows that rugby union players lose body fat during preseason training.

Perceptions and Determinants of Eating for Health and Performance in High-Level Male Adolescent Rugby Union Players

Sports nutrition recommendations provide guidance on dietary strategies to optimise sports performance. However, research indicates that young athletes often find it difficult to follow these guidelines in practice. Limited research exists on the determinants that influence adherence to sports nutrition guidelines. This study aimed to explore the perceptions and determinants of eating for health and performance in high-level male adolescent rugby union players. Determinants were explored using semi-structured individual interviews in New Zealand high-level male rugby union players (n = 20, 16–18 years). Interviews were recorded, transcribed, and then underwent thematic analysis. Perceptions of eating for health and performance included balance and variety, appropriate portions, and specific foods. Both adolescent- and sport-specific determinants influenced the food choices of participants. Determinants relevant to adolescent lifestyles included the influence of significant others such as peers and family but also included the taste, cost, convenience, and availability of food. Sports-specific determinants revolved around the desire to enhance sports performance, motivation to perform, and team culture. The media (mainstream and social media), physical appearance, and feeling good were identified as both adolescent- and sport-specific factors influencing food choice. These findings highlight the importance of having support and positive role modelling to help young athletes make optimal food choices for health and performance. Strategies to further enable healthy eating practices should aim to strengthen the support available to young athletes in the home, school, and sporting environments and should include education on appropriate social media use to inform eating for health and performance.

Validity of Dietary Assessment in Athletes: A Systematic Review

Dietary assessment methods that are recognized as appropriate for the general population are usually applied in a similar manner to athletes, despite the knowledge that sport-specific factors can complicate assessment and impact accuracy in unique ways. As dietary assessment methods are used extensively within the field of sports nutrition, there is concern the validity of methodologies have not undergone more rigorous evaluation in this unique population sub-group. The purpose of this systematic review was to compare two or more methods of dietary assessment, including dietary intake measured against biomarkers or reference measures of energy expenditure, in athletes. Six electronic databases were searched for English-language, full-text articles published from January 1980 until June 2016. The search strategy combined the following keywords: diet, nutrition assessment, athlete, and validity; where the following outcomes are reported but not limited to: energy intake, macro and/or micronutrient intake, food intake, nutritional adequacy, diet quality, or nutritional status. Meta-analysis was performed on studies with sufficient methodological similarity, with between-group standardized mean differences (or effect size) and 95% confidence intervals (CI) being calculated. Of the 1624 studies identified, 18 were eligible for inclusion. Studies comparing self-reported energy intake (EI) to energy expenditure assessed via doubly labelled water were grouped for comparison (n = 11) and demonstrated mean EI was under-estimated by 19% (-2793 ± 1134 kJ/day). Meta-analysis revealed a large pooled effect size of -1.006 (95% CI: -1.3 to -0.7; p < 0.001). The remaining studies (n = 7) compared a new dietary tool or instrument to a reference method(s) (e.g., food record, 24-h dietary recall, biomarker) as part of a validation study. This systematic review revealed there are limited robust studies evaluating dietary assessment methods in athletes. Existing literature demonstrates the substantial variability between methods, with under- and misreporting of intake being frequently observed. There is a clear need for careful validation of dietary assessment methods, including emerging technical innovations, among athlete populations.