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BackgroundBioelectrical impedance vector analysis (BIVA) is a general concept that includes all methodologies used in the analysis of the bioelectrical vector, whereas the "classic" BIVA is a patented methodology included among these methods of analysis. Once this was clarified, the systematic review of the literature provides a deeper insight into the scope and range of application of BIVA in sport and exercise.ObjectiveThe main goal of this work was to systematically review the sources on the applications of BIVA in sport and exercise and to examine its usefulness and suitability as a technique for the evaluation of body composition, hydration status, and other physiological and clinical relevant characteristics, ultimately to trace future perspectives in this growing area, including a proposal for a research agenda.MethodsSystematic literature searches in PubMed, SPORTDiscus and Scopus databases up to July, 2017 were conducted on any empirical investigations using phase-sensitive bioimpedance instruments to perform BIVA within exercise and sport contexts. The search included healthy sedentary individuals, physically active subjects and athletes.ResultNineteen eligible papers were included and classified as sixteen original articles and three scientific conference communications. Three studies analysed short-term variations in the hydration status evoked by exercise/training through whole-body measurements, eleven assessed whole-body body composition changes induced by long-term exercise, four compared athletic groups or populations using the whole-body assessment, and two analysed bioelectrical patterns of athletic injuries or muscle damage through localised bioimpedance measurements.ConclusionsBIVA is a relatively new technique that has potential in sport and exercise, especially for the assessment of soft-tissue injury. On the other hand, the current tolerance ellipses of “classic” BIVA are not a valid method to identify dehydration in individual athletes and a new approach is needed. “Specific” BIVA, a method which proposes a correction of bioelectrical values for body geometry, emerges as the key to overcome “classic” BIVA limitations regarding the body composition assessment. Further research establishing standardised testing procedures and investigating the relationship between physiology and the bioelectrical signal in sport and exercise is needed.

The aim of the present review is to investigate the main field-based tests, used alone or included in sport or fitness batteries, for the assessment of health-and skill-related physical fitness components in adolescents. Different scientific databases were searched through using the selected key words related to physical fitness and its components for adolescence. The search focused on original articles and reviews/meta-analyses using valid, reproducible and feasible tests that fit within the school environment. A total of 100 scientific manuscripts were included in the qualitative synthesis. The present systematic review pointed out 5 fitness tests that well adapt to the evaluation of the components of physical fitness of adolescents within a school environment: the 20 m shuttle run test for cardio-respiratory endurance; the handgrip strength test for upper body maximal strength; the standing broad jump test for lower body maximal strength; the sit-up test to exhaustion for muscular endurance and the 4×10 m shuttle run test for speed, agility and coordination. These fitness tests have been finally selected and incorporated into the Adolescents and Surveillance System for the Obesity prevention -Fitness Test Battery (ASSO-FTB), and will be adopted within the ASSO Project for evaluation purposes. This instrument could be also provided to teachers and people working in schools in order to assess physical fitness of adolescents over time and prevent obesity and related diseases.

Objective: The aim of the present work was to determine what dietary assessment method can provide a valid and accurate estimate of nutrient intake by comparison with the gold standard. Design: A MEDLINE, EMBASE, ISI Web of Science, Cochrane and related references literature review was conducted on dietary assessment methods for adolescents reporting the validity and/or reproducibility values. A study quality assessment on the retrieved FFQ was carried out according to two different scoring systems, judging respectively the quality of FFQ nutrition information and of FFQ validation and calibration. Setting: The present review considered adolescents attending high schools and recruited in hospitals or at home. Subjects: The target of the review was the healthy adolescent population in the age range 13-17 years. Results: Thirty-two eligible papers were included and analysed separately as 'original articles' (n 20) and 'reviews' (n 12). The majority (n 17) assessed the validation and reproducibility of FFQ. Almost all studies found the questionnaires to be valid and reproducible (r . 0?4), except for some food groups and nutrients. Different design and validation issues were highlighted, such as portion-size estimation, number of food items and statistics used. Conclusions: The present review offers new insights in relation to the characteristics of assessment methods for dietary intake in adolescents. Further meta-analysis is required although the current review provides important indications on the development of a new FFQ, addressing the need for a valid, reproducible, userfriendly, cost-effective method of accurately assessing nutrient intakes in adolescents. Keywords Dietary assessment Adolescents Validation ReproducibilityAdolescence is a critical period that is characterized by cognitive, emotional and social development and exposure to a significant turnover in lifestyle, including food intake and diet habits. Irregular meals, snacking and meal skipping, which characterize teenagers, often do not allow an accurate dietary assessment (1) and therefore the need to develop valid and reproducible instruments for this purpose is increasing. Different dietary assessment methods among adolescents have been extensively described and validated, such as food records (FR), FFQ, diet histories (DH) and 24 h recalls (24-HR). The FR is not used in large population studies for several reasons (2) : it can be quite expensive; it requires the participant to be literate and motivated; it involves trained staff; and it needs a computerized program specific to recording diet records. Thus, the FR is preferably used at the individual level and is generally considered a good reference instrument against which to validate other dietary methods to be used at the large population level, together with biomarker measurements (3) . The most used dietary assessment methods for large-scale surveys are therefore FFQ, 24-HR and DH, which present advantages such as cost-effectiveness, although they are affected by weaknesses (4,5) ...

BackgroundIt is known that supplement use is a widespread and accepted practice by athletes and people who attend commercial gyms. Little is known about protein supplement amongst people undertaking strength training in commercial gyms in Italy when compared to the US.ObjectiveThe purpose of this study was to examine the use of protein supplementation, alone or in association with other supplements, and dietary behavior amongst regular fitness center attendees in Palermo, Italy.DesignResistance training information have been collected from 800 regular fitness center attendees for the initial analysis. A specific questionnaire was generated for the experimentation. Data were collected using a face-to-face interview method. Supplement users were then compared to the non users and analyzed using a one-way ANOVA, Kruskall-Wallis, chi-square test or exact test of Fisher when appropriate.Results30.1% of the respondents use dietary supplements during their training as a believe it is the "way to gain muscles and strength". Whey protein shakes (50.0%) mixed with creatine and amino-acids (48.3%) were the most frequent choices amongst the users. A majority of the subjects (34.0%) appeared to rely on their gym instructors' advice for their intake; a lower proportion (13.0%) consulted physicians, while none of them consulted nutritionists. A high consumption of milk has been noticed in both users (67,7%) and non-users (52,8%); supplement non-users consumed significantly more snacks and bakery products than users per week (P < 0.001), while users consumed significantly more protein-rich foods (P < 0.01) with a particular preference for meat (48.0%).ConclusionsA considerable number of regular strength training adepts consume protein supplements mixed with other products (mainly creatine and amino-acids). Limited numbers consult "dietary specialists" and rely mainly on their instructors. We emphasize on the importance of the dissemination of scientifically based information about supplementation in this environment and the promotion of updated educational programs for the instructors.

Aerobic and anaerobic performance of the upper body (UB) and lower body (LB) were assessed by arm cranking and treadmill tests respectively in a comparison of national (N) and international (I) male gymnasts. Force velocity and Wingate tests were performed using cycle ergometers for both arms and legs. In spite of a significant difference in training volume (4- 12 vs. 27-34 h.wk(-1) for N and I, respectively), there was no significant difference between N and I in aerobic and anaerobic performance. Upper body and LB maximal oxygen uptake (VO(2)max) values were 34.44 +/- 4.62 and 48.64 +/- 4.63 ml.kg(-1).min(-1) vs. 33.39 +/- 4.77 and 49.49 +/- 5.47 ml.kg(-1).min(-1), respectively, for N and I. Both N and I had a high lactic threshold (LT), at 76 and 82% of VO(2)max, respectively. Values for UB and LB force velocity (9.75 +/- 1.12 and 15.07 +/- 4.25 vs. 10.63 +/- 0.95 and 15.87 +/- 1.25 W.kg(-1)) and Wingate power output (10.43 +/- 0.74 and 10.98 +/- 3.06 vs. 9.58 +/- 0.60 and 13.46 +/- 1.34 W.kg(-1)) were also consistent for N and I. These findings confirm the consistency of VO(2)max values presented for gymnasts in the last 4 decades, together with an increase in peak power values. Consistent values for aerobic and anaerobic performance suggest that the significant difference in training volume is related to other aspects of perfomance that distinguish N from I gymnasts. Modern gymnastics training at N and I levels is characterized by a focus on relative strength and peak power. In the present study, the high LT is a reflection of the importance of strength training, which is consistent with research for sports such as wrestling.

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Objective: The present work is aimed at meta-analysing validity studies of FFQ for adolescents, to investigate their overall accuracy and variables that can affect it negatively. Design: A meta-analysis of sixteen original articles was performed within the ASSO Project (Adolescents and Surveillance System in the Obesity prevention). Setting: The articles assessed the validity of FFQ for adolescents, compared with food records or 24 h recalls, with regard to energy and nutrient intakes. Subjects: Pearson's or Spearman's correlation coefficients, means/standard deviations, kappa agreement, percentiles and mean differences/limits of agreement (Bland-Altman method) were extracted. Pooled estimates were calculated and heterogeneity tested for correlation coefficients and means/standard deviations. A subgroup analysis assessed variables influencing FFQ accuracy. Results: An overall fair/high correlation between FFQ and reference method was found; a good agreement, measured through the intake mean comparison for all nutrients except sugar, carotene and K, was observed. Kappa values showed fair/ moderate agreement; an overall good ability to rank adolescents according to energy and nutrient intakes was evidenced by data of percentiles; absolute validity was not confirmed by mean differences/limits of agreement. Interviewer administration mode, consumption interval of the previous year/6 months and high number of food items are major contributors to heterogeneity and thus can reduce FFQ accuracy. Conclusions:The meta-analysis shows that FFQ are accurate tools for collecting data and could be used for ranking adolescents in terms of energy and nutrient intakes. It suggests how the design and the validation of a new FFQ should be addressed. Keywords Meta-analysis Validity FFQ AdolescentSemi-quantitative FFQ are valid and reliable dietary assessment methods used worldwide on adolescents and are suggested as appropriate tools for the collection of dietary intake data in large-scale surveys (1,2) , since they have the advantages of ease of administration, saving of economic resources and ability to assess dietary intake over an extended period of time (3) . Among all the used FFQ, large variations in design characteristics have been highlighted (4) , such as number of food items or consumption interval.Our recent systematic literature review (5) identified the FFQ used in adolescents and validated during the last decade throughout the world. One of the aspects emphasized by the review is that there is an ongoing need for the refinement of existing approaches, especially ones that can be used in large epidemiological studies.When preparing the tools for dietary data collection, the specific design and validation issues of the data collecting instrument have to be taken into account. There are many factors that may affect the accuracy of a dietary questionnaire such as respondent characteristics, questionnaire design and quantification, adequacy of the reference data, quality control and data management (6) , including ...