Associations Between Substitution of Sedentary Behavior Patterns With Physical Activity and Cardiovascular Risk Factors in Adolescents: A 3-Year Longitudinal Study.

BACKGROUND: Little is known on how the substitution of time spent in sedentary behavior (SB) patterns with time spent in physical activity impacts cardiovascular risk factors during adolescence. The study aimed to investigate how the substitution of time spent in SB and sedentary bouts with time spent in different physical activity intensities was associated with longitudinal changes in cardiovascular risk factors in analyses stratified by sex. METHODS: This is a prospective cohort study with a mean follow-up period of 3.2 (±0.34) years, involving 109 (60 girls and 49 boys) Brazilian adolescents. Body mass index, waist circumference, and cardiorespiratory fitness were the cardiovascular risk factors considered. A cardiovascular risk score was calculated. Sedentary bouts, light physical activity (LPA), and moderate to vigorous physical activity (MVPA) were measured by accelerometers. Multivariate linear regression models adopting the isotemporal substitution were used to analyze the association between substitution of 10 minutes per day of sedentary bouts with LPA and MVPA and risk factors. All analyses considered 5% significance levels. RESULTS: Substitutions of SB, short and long bouts, with MVPA were associated with higher cardiorespiratory fitness in boys (ß = 0.077; 95% confidence interval, 0.001 to 0.55; ß = 0.076; 95% confidence interval, 0.003 to 0.154; and ß = 0.084; 95% confidence interval, 0.001 to 0.167, respectively). No associations were observed when analyses involved substitution of sedentary bouts with LPA, adiposity, cardiovascular risk score, and girls. CONCLUSIONS: Substituting SB bouts with MVPA appears to favorably influence changes of cardiorespiratory fitness in boys during adolescence. Greater benefits appear to occur when longer sedentary bouts are substituted by MVPA.

Tradução e adaptação transcultural do questionário "Barriers to Being Active Quiz (BBAQ)'' para a língua portuguesa brasileira / Translation and cross-cultural adaptation of the questionnaire "Barriers to Being Active Quiz (BBAQ)" into Brazilian Portuguese language

Objetivou-se nesse estudo a tradução e validação transcultural do questionário Barriers to Being Active Quiz (BBAQ) para adolescentes brasileiros. Foram realizadas as seguintes etapas: (1) tradução do questionário original em inglês para o português; (2) resolução de divergências entre a versão 1 e a versão 2 e criação da versão síntese; (3) retrotradução para o inglês; (4) revisão e avaliação do comitê de especialistas, construção da versão pré-teste; e (5) pré-teste com a avaliação da compreensão por uma amostra (n = 30) da população-alvo. A versão final do BBAQ possui 21 questões. O questionário foi considerado de fácil entendimento por 70,0% dos adolescentes e os outros 30,0% dos adolescentes avaliaram o entendimento e a dificuldade de compreensão do questionário como moderado. Nenhum adolescente considerou o questionário como de difícil compreensão. O tempo médio para o preenchimento do BBAQ foi de 11 min (IC 95% = 9 ­ 12). O valor geral do Alfa de Cronbach com base nos itens padronizados do questionário foi de 0,86. O estudo apresentou evidências satisfatórias de validade e confiabilidade. Portanto, recomenda-se a utilização da adaptação transcultural do BBAQ para a avaliação de barreiras à prática de atividade física em adolescentes brasileiros.

The aim of the study was to perform the translation and cross-cultural validation of the Barriers to Being Active Quiz (BBAQ) questionnaire for Brazilian adolescents. The following steps were taken: (1) transla-tion of the original questionnaire from English to Portuguese; (2) resolution of discrepancies between version 1 and version 2 and creation of a synthesis version; (3) back-translation from Portuguese to English; (4) review and evaluation by an expert committee, construction of the pre-test version; and (5) pre-testing with comprehension assessment by a sample (n = 30) of the target population. The final version of the BBAQ com-prises 21 questions. The questionnaire was considered easy to understand by 70,0% of adolescents, while the remaining 30,0% rated the questionnaire's understanding and comprehension difficulty as moderate. None of the participants rated the questionnaire as difficult to understand. The average time for completing the BBAQ was 11 minutes (CI 95% = 9 ­ 12). The overall Cronbach's Alpha value, based on the standardized questionnaire items, was 0.86. The study presented satisfactory evidence of validity and reliability. There-fore, we recommend the use of the cross-cultural adaptation of the BBAQ for assessing barriers to physical activity among Brazilian adolescents.

The use of wearable resistance and weighted vest for sprint performance and kinematics: a systematic review and meta-analysis.

Wearable resistance (WR) and weighted vests (WV) can be used in almost all training conditions to enhance sprint performance; however, positioning and additional mass are different in WV and WR strategies, affecting performance and kinematics differently. We aimed to systematically review the literature, searching for intervention studies that reported the acute or chronic kinematic and performance impact of WV and WR and comparing them. We analyzed Pubmed, Embase, Scopus, and SPORTDiscuss databases for longitudinal and cross-over studies investigating sprint performance or kinematics using an inverse-variance with a random-effect method for meta-analysis. After the eligibility assessment, 25 studies were included in the meta-analysis. Cross-over WR and WV studies found significantly higher sprint times and higher ground contact times (CT) compared to unloaded (UL) conditions. However, WR presented a lower step frequency (SF) compared to UL, whereas WV presented a lower step length (SL). Only one study investigated the chronic adaptations for WR, indicating a superiority of the WR group on sprint time compared to the control group. However, no difference was found chronically for WV regarding sprint time, CT, and flight time (FT). Our findings suggest that using WV and WR in field sports demonstrates overload sprint gesture through kinematic changes, however, WR can be more suitable for SF-reliant athletes and WV for SL-reliant athletes. Although promising for chronic performance improvement, coaches and athletes should carefully consider WV and WR use since there is no supporting evidence that WV or WR will impact sprint performance, CT, and FT.

Time Reallocations From Sedentary Behavior to Physical Activity and Cardiovascular Risk Factors in Children and Adolescents: A Systematic Review.

BACKGROUND: Recent statistical approaches have allowed consideration of the integrated relationships between sedentary behavior (SB) and physical activity (PA) with different health outcomes. The present paper aimed to systematically review the literature and synthesize evidence about associations between hypothetical reallocations from SB to different PA intensities and cardiovascular risk factors in youth. METHODS: A systematic search of 8 databases was performed. Observational studies with a population of children and/or adolescents and based on statistical analysis that investigated the associations between time reallocations from SB to PA and cardiovascular risk factors were included. RESULTS: Twenty-eight studies met the inclusion criteria. Level of evidence (derived from cross-sectional studies) indicated that the reallocation from SB to moderate to vigorous PA was beneficially associated with adiposity, cardiorespiratory fitness, and cardiometabolic biomarkers in youth. Reallocation from SB to light PA was not associated with the analyzed outcomes. Associations derived from longitudinal studies were mostly inconclusive. CONCLUSION: Cardiovascular risk factors could be improved by increasing moderate to vigorous PA at the expense of time spent in SB in pediatric populations. Prospective studies or studies investigating the effects of reallocating sedentary bouts to PA are needed.

Ischemic Preconditioning Improves the Bench-Press Maximal Strength in Resistance-Trained Men.

We investigated whether acute ischemic preconditioning (IPC) would affect upper limb maximal strength performance in resistance-trained men. Using a counterbalanced randomized crossover design, fifteen men (29.9 ± 5.9 yrs.; 86.3 ± 9.6 kg; 8.0 ± 5.0 yrs. resistance training experience) performed one-repetition maximum (1-RM) bench press tests on three different occasions: control, 10 min post-IPC or 10 min post-placebo (SHAM). One-way analysis of variance showed that the post-IPC condition increased (P < 0.0001) 1-RM loads compared to both control and post-SHAM (control 113.3 ± 15.9 kg vs. SHAM 113.9 ± 15.8 kg vs. IPC 115.7 ± 15.6 kg), while control and SHAM did not differ (P > 0.05). Individual results showed that 13 participants (~87%) improved their performance post-IPC compared to control, and 11 participants (~73%) performed better post-IPC compared to post-SHAM. Reported session rating of perceived exertion (RPE) was lower (P < 0.0001) post-IPC (8.5 ± 0.6 arb.u) compared to control (9.3 ± 0.5 arb.u) and post-SHAM (9.3 ± 0.5 arb.u). Therefore, we conclude that IPC acutely improves upper limb maximal strength performance and reduces session-RPE in resistance-trained men. These results suggest an acute ergogenic effect of IPC for strength and power sports such as powerlifting.

Associations of Physical Activity and Sedentary Behavior With Survival Time in Older Adults: Path Analysis.

This study investigated the direct and indirect associations of physical activity and sedentary behavior with survival time in older adults. Prospective population-based cohort study used exploratory survey-type methods and physical performance tests in 319 adults aged ≥60 years. Trajectory diagrams were used to represent the initial hypothetical and final models with the relationships of independent, mediating, and dependent variables. Physical activity was indirectly associated with survival time and was mediated by instrumental activities of daily living and functional performance. In contrast, instrumental activities of daily living, functional performance, the number of hospitalizations, and medications mediated the association between duration of sedentary behavior and survival time. The explanatory power of the final model was 19%. Future efforts should focus on increasing the participation and adherence of older adults to exercise programs to improve their physical functions and general health, which may increase their health period and, consequently, their survival time.

Atividade física objetiva em jovens com espinha bífida: um protocolo de revisão sistemática / Objective physical activity in youth with spina bifida: a systematic review protocol

Atividade física (AF) diária associa-se a melhora do estado de saúde de jovens. Evidências indicam que crianças com espinha bífida (EB) estão em risco para inatividade física. Este artigo apresenta um protocolo de revisão sistemática que propõe avaliar níveis de AF objetiva diária em crianças e adoles-centes com EB. Este protocolo foi desenvolvido seguindo o Preferred Reporting Items for Systematic Review and Meta-Analysis Protocols (PRISMA-P) 2015. A revisão foi registrada no International Prospective Register of Systematic Reviews (PROSPERO, CRD42022349920). Os critérios de inclu-são baseiam-se em artigos originais: 1) publicados em revistas com revisão por pares; 2) que avaliem AF objetiva diária em crianças e adolescentes com EB; e 3) que utilizem monitores para avaliação da AF (ex: acelerômetros). Palavras-chave foram baseadas no MeSH e literatura existente. As seguin-tes bases de dados serão utilizadas como fontes de informação: PubMed, Embase, SPORTDiscus, LILACS, CINAHL, Scopus, PsycINFO e Web of Science. Os seguintes dados serão extraídos: características do estudo e da amostra, variáveis de AF (protocolos de medição e pontos de corte de classificação de AF) e resultados dos níveis de AF. A qualidade dos estudos será avaliada com o Standard Quality Assessment Criteria for Evaluating Primary Research Papers from a Variety of Fields(ERA). A busca e seleção dos estudos, extração de dados e avaliação de qualidade serão realizadas por dois revisores independentes. Espera-se que a revisão forneça evidências para auxiliar na pre-venção e tratamento de inatividade física e guiar futuras pesquisas sobre AF objetiva em crianças e adolescentes com EB

Daily physical activity (PA) is associated with improvements in health status in youth. However, evidence indicates that children with spina bifida (SB) are at risk for physical inactivity. This paper documents a systematic review protocol that aims to examine daily objective PA levels in children and adolescents with SB. This protocol was developed following the Preferred Reporting Items for Systematic Review and Me-ta-Analysis Protocols (PRISMA-P) 2015. The protocol was registered on the International Prospective Register of Systematic Reviews (PROSPERO, CRD42022349920). The inclusion criteria are based on original articles: 1) published in peer-reviewed journals; 2) examining daily objective PA in children and adolescents with SB; and 3) using PA monitors to measure PA (e.g., accelerometers). Key words were de-termined based on MeSH and existing literature. The following databases will be used as sources of infor-mation: PubMed, Embase, SPORTDiscus, LILACS, CINAHL, Scopus, PsycINFO, and Web of Science. Study and sample characteristics, PA variables (measurement protocols and PA classification cut-points) and PA levels results will be extracted from the studies. The quality of studies will be assessed with the Standard Quality Assessment Criteria for Evaluating Primary Research Papers from a Variety of Fields (ERA). The search and selection of articles, and extraction of data and quality assessment will be performed by two in-dependent reviewers. It is expected that this study provides evidence to support prevention and treatment of physical inactivity and guide future research directions in objective PA in children and adolescents with SB

Effects of a Physical Exercise Program and Health Advice on Sedentary Behavior of Adolescents.

Sedentary behavior (SB) is a risk factor for chronic non-communicable diseases. This study aimed to assess the effects of an extracurricular physical exercise program and health advice on SB in adolescents. This was a non-randomized experimental study involving 19 adolescents divided into an intervention group (IG) and a control group (CG), aged 13-16 years from a public school in a Brazilian municipality. SB was measured using self-reports and accelerometers. The intervention included physical exercise and health advice. Repeated measures analysis of variance with a significance level of α = 5% was used. There was a time*group interaction for the subscapular fold ((pre IG = 16.30 mm vs. CG = 13.44 mm, post IG = 14.00 mm vs. CG = 15.89 mm) p = 0.001), and VO2MAX ((pre IG = 32.75 mL/kg/min vs. CG = 30.66 mL/kg/min, post IG = 35.76 mL/kg/min vs. CG = 29.28 mL/kg/min) p = 0.008). The accelerometer showed significant differences between groups in the total SB ((pre IG = 647.49 min/day vs. CG = 535.24 min/day, post IG = 614.02 min/day vs. CG = 586.97 min/day) p = 0.045), with a significant decrease in the IG. In conclusion, an extracurricular physical exercise program and health advice was effective in reducing SB in adolescents.

The Influence of L-menthol on Time Trial Running Performance in Recreational Runners.

Purpose: This study investigated the effects of combined mouth rinse and topical application of L-menthol on perceptual responses and running performance under thermoneutral conditions (22 ± 2°C and 30-60% relative humidity). Methods: Twelve recreational male runners (age: 31.7 ± 3.8 years; age range: 27-39 years) completed a familiarization, a control test (CON) and two maximal 10-km time trials (counterbalanced randomized crossover design) performed in different days with a non-thermal cooling intervention (combined application of a L-menthol mouth rinse and topical L-menthol gel - MEN) or placebo (PLA). Performance and perceptual measures (thermal sensation, thermal comfort, ratings of perceived exertion and affective response) were recorded for every km completed in the 10-km test. Results: Performance time was lower in MEN (P = 0.03) and PLA (P = 0.003) compared to CON, but no differences were found between MEN vs PLA (P = 1.00). All perceptual responses increased over time in all conditions (P < 0.0001), but only the thermal sensation was lower (P = 0.01) in the MEN compared to CON. Conclusion: L-menthol strategies promote fresh sensations and may improve running performance in 10-km time trial in recreational runners, but the performance improvement could mainly be due to a placebo effect.

Time-use movement behaviors are associated with scores of depression/anxiety among adolescents: A compositional data analysis.

Movement behaviors have been associated with mental health. The purposes of this study were to examine the association between movement behaviors and scores of depression/anxiety among adolescents and to determine the difference in depression/anxiety associated with reallocating time between different movement behaviors. This cross-sectional study included 217 Brazilian adolescents (15 to 18 years old, 49.3% female). Adolescents wore an accelerometer for one week to assess the four-movement behaviors which include sleep, sedentary behavior (SB), light physical activity (LPA), and moderate-to-vigorous physical activity (MVPA). The depression/anxiety score was calculated by factor analysis using the 12-item General Health Questionnaire. Compositional data analyses were used to examine the association between movement behavior and the depression/anxiety score. Compositional isotemporal substitution models estimated the change in depression/anxiety score associated with reallocating 10, 30, and 60 min between movement behaviors. The composition of movement behaviors was significantly associated with depression/anxiety scores (p < 0.05). Replacing time from SB to LPA was associated with improvement in the depression/anxiety score, while the inverse was associated with an increase in this score. Replacing time of LPA with MVPA was associated with worsening in the depression/anxiety score. The 24-h time distribution of the day may play a crucial role in mental health. Compositions with more time spent in LPA at the expense of less SB are associated with improvement in the scores of depression/anxiety. The type of MVPA may moderate its effects on depression/anxiety in adolescents. Holistic interventions including the full range of movement behaviors may be a gateway to reduce the levels of depression/anxiety in adolescence.

Current Perspectives of Cross-Country Mountain Biking: Physiological and Mechanical Aspects, Evolution of Bikes, Accidents and Injuries.

Mountain biking (MTB) is a cycling modality performed on a variety of unpaved terrain. Although the cross-country Olympic race is the most popular cross-country (XC) format, other XC events have gained increased attention. XC-MTB has repeatedly modified its rules and race format. Moreover, bikes have been modified throughout the years in order to improve riding performance. Therefore, the aim of this review was to present the most relevant studies and discuss the main results on the XC-MTB. Limited evidence on the topic suggests that the XC-MTB events present a variation in exercise intensity, demanding cardiovascular fitness and high power output. Nonetheless, these responses and demands seem to change according to each event. The characteristics of the cyclists differ according to the performance level, suggesting that these parameters may be important to achieve superior performance in XC-MTB. Moreover, factors such as pacing and ability to perform technical sections of the circuit might influence general performance. Bicycles equipped with front and rear suspension (i.e., full suspension) and 29″ wheels have been shown to be effective on the XC circuit. Lastly, strategies such as protective equipment, bike fit, resistance training and accident prevention measures can reduce the severity and the number of injuries.

Pedometers and Accelerometers in Multiple Sclerosis: Current and New Applications.

Pedometers and accelerometers have become commonplace for the assessment of physical behaviors (e.g., physical activity and sedentary behavior) in multiple sclerosis (MS) research. Current common applications include the measurement of steps taken and the classification of physical activity intensity, as well as sedentary behavior, using cut-points methods. The existing knowledge and applications, coupled with technological advances, have spawned new opportunities for using those motion sensors in persons with MS, and these include the utilization of the data as biomarkers of disease severity and progression, perhaps in clinical practice. Herein, we discuss the current state of knowledge on the validity and applications of pedometers and accelerometers in MS, as well as new opportunities and strategies for the improved assessment of physical behaviors and disease progression, and consequently, personalized care.

Effects of aerobic exercise combined with resistance training on health-related physical fitness in adolescents: A randomized controlled trial.

Background: /Objective: This study aimed to compare the effects of two combined training methods on health-related physical fitness components in adolescents. Methods: Seventy-six adolescents (16.1 ± 1.1 years, n = 44 female) were randomized into groups of moderate-intensity continuous training combined with resistance training (MICT + RT), high-intensity interval training combined with resistance training (HIIT + RT), or Control. The training sessions were performed twice weekly for 12 weeks. The health-related physical fitness components evaluated were: body composition, muscular and cardiorespiratory fitness. Results: The intervention groups had a significant reduction in body fat percentage and improvement in abdominal repetitions and VO2peak after 12 weeks of combined exercise program (p < 0.001). Intervention effects were found to significantly reduce body fat percentage for the MICT + RT and HIIT + RT groups compared to the control group (mean difference: -3.8; 95% CI: -6.2; -1 0.3; mean difference: -4.7; 95%CI: -7.1; -2.3, respectively). For muscle fitness, significant effects of the intervention were found in increasing the number of abdominal repetitions favoring the MICT + RT group compared to the control group (mean difference: 9.5; 95% CI: 4.4; 14.7) and HIIT + RT compared to the control group (mean difference: 14.1; 95% CI 9; 19.3). For cardiorespiratory fitness, significant effects of the intervention on improving VO2peak were found in the experimental groups (MICT + RT vs Control group: mean difference: 4.4; 95% CI: 2.2; 6.6; and HIIT + RT vs. Control group: mean difference: 5.5, 95% CI: 3.3; 7.7). Conclusion: The results suggest that 12 weeks of training using MCIT + RT or HIIT + RT showed a similar effect for health-related physical fitness components in adolescents.

Positive Implicit Associations for Physical Activity Predict Physical Activity and Affective Responses During Exercise.

The purpose of this study was to investigate the relationships of implicit associations and explicit evaluations with affective responses during an aerobic exercise session, physical activity, and sedentary behavior in adults. Fifty adults (70% women; median age = 31 years; 25th, 75th percentiles: 24.50, 40.50 years old; body mass index = 25.29 ± 4.97 kg/m2) not engaged in regular physical activity completed an implicit association test and a questionnaire of explicit evaluations and wore an accelerometer for 7 days. After the 7-day period, the participants performed 30 min of moderate-intensity aerobic exercise. Every 5 min, the affective response and the perception of effort were recorded. Participants who had more positive implicit associations toward physical activity (vs. sedentary behavior) reported higher affective responses during exercise and engaged in more moderate to vigorous physical activity. Encouraging pleasant physical activity may act to partially improve future physical activity through automatic motivational processes.

Mensuração da atividade física e comportamento sedentário: uma análise baseada em grupos de pesquisa / Measurement of physical activity and sedentary behavior: a research group-based analysis

O presente estudo caracterizou os grupos de pesquisa brasileiros que possuem linhas de pesquisa voltadas à temática da mensuração da atividade física e/ou comportamento sedentário. Autores de artigos originais envolvendo desenvolvimento, adaptação, tradução e testagem de qualidade de medidas de instrumentos da atividade física/comportamento sedentário na população brasileira foram convidados a responder um instrumento online contendo 19 questões para a identificação de líderes e de características gerais dos grupos de pesquisa. Vinte e oito grupos de pesquisa foram identificados, sendo o pioneiro criado na década de 1970 e a maioria nas últimas duas décadas. Enquanto a região sudeste apresentou a maior concentração de grupos, foi identificada ausência de grupos nas regiões norte e centro-oeste. Os métodos de mensuração mais testados por estes grupos foram os subjetivos, predominantemente questionários (n = 24), seguidos pelos métodos objetivos por meio de acelerômetros (n = 18) e pedômetros (n = 9). Foram identificadas várias conexões (parcerias permanentes com outros grupos/instituições) em nível nacional e internacional, especialmente com países da América do Norte, Europa e Austrália. Espera-se que os resultados do presente estudo possam estimular ações colaborativas entre grupos e pesquisadores brasileiros com o intuito de reduzir desigualdades regionais e aprimorar a produção do conhecimento na área da mensuração da atividade física e do comportamento sedentário

The present study characterized the Brazilian research groups that have research lines focused on the meas-uring of physical activity and/or sedentary behavior. Authors of original articles that involved the devel-opment, adaptation, translation, and quality testing of measures of physical activity/sedentary behavior instruments in the Brazilian population were invited to answer an online instrument containing 19 questions to identify leaders and general characteristics of research groups. Twenty-eight research groups were identified, the pioneer being created in the 1970's and the majority in the last two decades. While the Southeast region had the highest concentration of groups, the absence of groups was identified in the North and Midwest regions. The measurement methods most tested by these groups were subjective, predominantly questionnaires (n = 24), followed by objective methods using accelerometers (n = 18) and pedometers (n = 9). Several connections (permanent partnerships with other groups/institutions) were identified at national and international levels, especially with countries in North America, Europe, and Australia. It is expected that the results of the present study can stimulate collaborative actions between Brazilian groups and re-searchers to reduce regional inequalities and improve the production of knowledge in the area of measuring physical activity and sedentary behavior

Grupo de Trabalho em Mensuração da Atividade Física e Comportamento Sedentário: uma breve Apresentação / Work Group on Measurement of Physical Activity and Sedentary Behavior: a Brief Presentation

A Sociedade Brasileira de Atividade Física & Saúde (SBAFS) exerce importante papel na união dos pesquisadores e fortalecimento da área no Brasil. Por essa razão, as decisões e direcionamentos das diferentes gestões da SBAFS, auxiliam, no desenvolvimento e consolidação da área. Uma das importantes ações da SBAFS nos últimos anos foi a criação de Grupos de Trabalhos (GTs) sobre diferentes temáticas da atividade física e saúde. Um dos GTs criados foi o GT de Mensuração da Atividade Física e Comportamento Sedentário. Neste contexto, o presente manuscrito descreve a criação do referido GT, suas atividades e ações no período de 2019 e 2021

The Brazilian Society of Physical Activity & Health (SBAFS) plays an important role in uniting researchers and strengthening the field in Brazil. For this reason, the decisions and directions of the different leader-ships of SBAFS help in the development and consolidation of the area. One of the important actions of the SBAFS in recent years was the creation of Working Groups ( WGs) on different themes of physical activity and health. One of the WGs created was the Physical Activity and Sedentary Behavior Measurement WG. In this context, the aim of this manuscript is to describe the creation of the aforementioned WG, its activities and actions in the period of 2019 to 2021

Smartphone apps for tracking physical activity and sedentary behavior: A criterion validity review / Aplicativos de smartphone para monitorar a atividade física e o comportamento sedentário: uma revisão sistemática de estudos de validação

Smartphone apps have been developed and investigated in validation studies for tracking human be-havior such as physical activity (PA) and sedentary behavior (SB). However, as it is unclear whether these apps are valid for tracking PA and SB when compared to research-grade accelerometers, thus, this systematic review aimed to investigate the validity of smartphone apps for tracking PA and SB using the accelerometer as a criterion measure. A systematic search was conducted in PubMed, Web of Science, SportDiscus, and Scopus databases. The mean percentage difference (MPD) was used to evaluate criterion validity. Ten studies (n = 662) validating different apps using ActiGraph accelerometers as criteria measure (six were conducted in free-living conditions, two in laboratory conditions, and two in both conditions) were included for analyses. While four apps were considered valid for tracking PA, six were not valid or fully valid. The MPD analysis revealed that apps provide no valid scores for tracking PA measures (MPD = -12.6 ­ 37.7). The scarcity of studies investigat-ing SB limits the tracking of the results on this behavior. Study designs, smartphone location, and exercise intensity tend to affect the accuracy of apps tracking PA; thus, the current review showed conflicting results among studies. This review shows that it is not possible to generalize the valid scores for all apps

Aplicativos para smartphones têm sido desenvolvidos e investigados em estudos de validação para rastrea-mento de comportamento humano, como atividade física (AF) e comportamento sedentário (CS). No entan-to, como não está claro se esses aplicativos são válidos para rastrear AF e CS quando comparados a acelerôme-tros de grau de pesquisa, portanto, essa revisão sistemática teve o objetivo investigar a validade de aplicativos de smartphone para rastreamento de AF e CS usando o acelerômetro como medida de critério. Uma busca sistemática foi realizada em quatro bases de dados. A diferença percentual média (MPD) foi utilizada para avaliar a validade de critério. Dez estudos (n = 662) validando diferentes aplicativos usando acelerômetros ActiGraph como medida de critério (seis foram realizados em condições de vida diária, dois em condições de laboratório e dois em ambas as condições) foram incluídos para análise. Enquanto quatro aplicativos foram considerados válidos para rastreamento de AF, seis não eram válidos ou totalmente válidos. A análise do MPD revelou que os aplicativos não fornecem pontuações válidas para rastrear medidas de AF (MPD = -12,6 ­ 37,7). A escassez de estudos investigando o CS limita o rastreamento dos resultados sobre esse comportamento. Desenhos de estudo, localização do smartphone e intensidade do exercício tendem a afetar a precisão dos aplicativos que rastreiam AF; assim, a presente revisão mostrou resultados conflitantes entre os estudos. Esta revisão mostra que não é possível generalizar as pontuações válidas para todos os aplicativos.