Are bodybuilding and cross-training practices dangerous for promoting orofacial injuries? A scoping review.

Bodybuilding and cross-training exercises bring health benefits. However, orofacial injuries can occur during practice. This study aimed to map, analyze, interpret, and synthesize data from studies on the main orofacial injuries resulting from bodybuilding and cross-training practices. This scoping review followed the Joanna Briggs Institute and PRISMA-ScR methods, with high-sensitivity searches in PubMed, Web of Science, Scopus, ScienceDirect, Embase, Virtual Health Library and the Google Scholar. Original scientific articles published up to May 2024 were included, which evaluated the presence of self-reported or professionally diagnosed orofacial injuries by bodybuilding and cross-training practitioners aged 18 years or older. Literature reviews, editorials, and guidelines were excluded. Tables and figures were used to map and summarize the results. Out of 30.485 potentially eligible articles, four were included. The main orofacial injuries identified in both bodybuilding and cross-training practitioners were dental damage (n = 4), temporomandibular joint (TMJ) disorders (n = 3), and traumas to oral soft tissues (n = 2) and facial soft tissues (n = 2). Dental damage and TMJ disorders were the most prevalent conditions among bodybuilding and cross-training practitioners. Therefore, dental damage and TMJ disorders were the most prevalent conditions among bodybuilding and cross-training practitioners. However, further prospective studies with more in-depth methodological designs and fewer biases are necessary.

Intermittent fasting and high-intensity interval training do not alter gut microbiota composition in adult women with obesity.

Obesity is advancing at an accelerated pace, and yet its treatment is still an emerging field. Although studies have demonstrated the role of the microbiota in the pathogenesis of obesity, this is the first study to show the effects of intermittent fasting (IF), combined or not with exercise, and high-intensity interval training (HIIT) on the gut microbiota composition in women with obesity. Our hypothesis is that IF combined with HIIT can promote the remodeling of the composition and function of the gut microbiota. Thirty-six women with obesity, aged between 18 and 40 yr, participated in the study. They were randomly divided into three groups: 1) IF associated with HIIT group [IF + exercise group (EX), n = 15]; 2) HIIT group (EX, n = 11); and 3) IF group (IF, n = 10). Interventions took place over 8 wk, and all assessments were performed preintervention and postintervention. The HIIT circuit was performed 3 times/wk, for 25 min/session. The IF protocol was a 5:2 (2 times/wk). Multiplex analysis of inflammatory cytokines, sequencing of the 16S rRNA gene, and gas chromatography to measure fecal concentrations of short-chain fatty acids (SCFAs) were performed. This study was registered on ClinicalTrials.gov (NCT05237154). Exercise increased fecal acetate concentrations (P = 0.04), but no changes were observed in the composition and functional profile of the microbiota. The interventions did not change the composition of the microbiota, but exercise may play a modulatory role in the production of acetate. This investigation provides clinical insights into the use of IF and HIIT for women with obesity.NEW & NOTEWORTHY This is the first investigation about alternate-day fasting combined with HITT on the gut microbiota of obese women. The study contributes to the advancement of human science involving IF and HIIT, popular strategies for managing obesity. Previous evidence has explored IF in modulating the microbiota in animal models or specific populations and clinical conditions. Despite the subtle outcomes, this study has relevance and originality in the field of gut microbiota knowledge.

Moderate-Intensity Constant and High-Intensity Interval Training Confer Differential Metabolic Benefits in Skeletal Muscle, White Adipose Tissue, and Liver of Candidates to Undergo Bariatric Surgery.

Background/Objectives: Bariatric surgery candidates require presurgical physical training, therefore, we compared the metabolic effects of a constant moderate-intensity training program (MICT) vs. a high-intensity interval training (HIIT) in this population. Methods: Seventeen participants performed MICT (n = 9, intensity of 50% of heart rate reserve (HRR) and/or 4-5/10 subjective sensation of effort (SSE)) or HIIT (n = 8, 6 cycles of 2.5 min at 80% of the HRR and/or 7-8/10 of SSE, interspersed by 6 cycles of active rest at 20% of the FCR) for 10 sessions for 4 weeks. After training, tissue samples (skeletal muscle, adipose tissue, and liver) were extracted, and protein levels of adiponectin, GLUT4, PGC1α, phospho-AMPK/AMPK, collagen 1 and TGFß1 were measured. Results: Participants who performed MICT showed higher protein levels of PGC-1α in skeletal muscle samples (1.1 ± 0.27 vs. 0.7 ± 0.4-fold change, p < 0.05). In the liver samples of the people who performed HIIT, lower protein levels of phospho-AMPK/AMPK (1.0 ± 0.37 vs. 0.52 ± 0.22-fold change), PGC-1α (1.0 ± 0.18 vs. 0.69 ± 0.15-fold change), and collagen 1 (1.0 ± 0.26 vs. 0.59 ± 0.28-fold change) were observed (all p < 0.05). In subcutaneous adipose tissue, higher adiponectin levels were found only after HIIT training (1.1 ± 0.48 vs. 1.9 ± 0.69-fold change, p < 0.05). Conclusions: Our results show that both MICT and HIIT confer metabolic benefits in candidates undergoing bariatric surgery; however, most of these benefits have a program-specific fashion. Future studies should aim to elucidate the mechanisms behind these differences.

Hypotensive effects of exercise training: are postmenopausal women with hypertension non-responders or responders?

We tested the hypothesis that increasing the exercise dose or changing the exercise mode would augment hypotensive effects when traditional aerobic exercise training failed to produce it in postmenopausal women. Sixty-five postmenopausal women with essential hypertension were randomly allocated into the continuous aerobic training (CAT) and non-exercising control (CON) groups. CAT group cycled at moderate intensity 3 times a week for 12 weeks. Individuals who failed to decrease systolic blood pressure (BP) were classified as non-responders (n = 34) and performed an additional 12 weeks of exercise training with either increasing the exercise dose or changing the exercise mode. The 3 follow-up groups were continuous aerobic training 3 times a week, continuous aerobic training 4 times a week, and high-intensity interval training. After the first 12 weeks of exercise training, systolic BP decreased by 1.5 mmHg (NS) with a wide range of inter-individual responses (-23 to 23 mmHg). Sixty-seven percent of women who were initially classified as non-responders participated in the second training period. Sixty percent of women who participated in continuous exercise training 3 or 4 times a week at greater exercise intensities reduced systolic BP. All (100%) of the women who performed high-intensity interval training experienced significant reductions in systolic BP. Traditional aerobic exercise was not sufficient to decrease BP significantly in the majority of postmenopausal women. However, those women who were not sensitive to recommended exercise may reduce BP if they were exposed to continuous aerobic exercise at higher intensities and/or volumes or a different mode of exercise.

Exercise enhances hepatic mitochondrial structure and function while preventing endoplasmic reticulum stress and metabolic dysfunction-associated steatotic liver disease in mice fed a high-fat diet.

Metabolic dysfunction-associated steatotic liver disease (MASLD) has attracted increasing attention from the scientific community because of its severe but silent progression and the lack of specific treatment. Glucolipotoxicity triggers endoplasmic reticulum (ER) stress with decreased beta-oxidation and enhanced lipogenesis, promoting the onset of MASLD, whereas regular physical exercise can prevent MASLD by preserving ER and mitochondrial function. Thus, the hypothesis of this study was that high-intensity interval training (HIIT) could prevent the development of MASLD in high-fat (HF)-fed C57BL/6J mice by maintaining insulin sensitivity, preventing ER stress, and promoting beta-oxidation. Forty male C57BL/6J mice (3 months old) comprised 4 experimental groups: the control (C) diet group, the C diet + HIIT (C-HIIT) group, the HF diet group, and the HF diet + HIIT (HF-HIIT) group. HIIT sessions lasted 12 minutes and were performed 3 times weekly by trained mice. The diet and exercise protocols lasted for 10 weeks. The HIIT protocol prevented weight gain and maintained insulin sensitivity in the HF-HIIT group. A chronic HF diet increased ER stress-related gene and protein expression, but HIIT helped to maintain ER homeostasis, preserve mitochondrial ultrastructure, and maximize beta-oxidation. The increased sirtuin-1/peroxisome proliferator-activated receptor-gamma coactivator 1-alpha expression implies that HIIT enhanced mitochondrial biogenesis and yielded adequate mitochondrial dynamics. High hepatic fibronectin type III domain containing 5/irisin agreed with the antilipogenic and anti-inflammatory effects observed in the HF-HIIT group, reinforcing the antisteatotic effects of HIIT. Thus, we confirmed that practicing HIIT 3 times per week maintained insulin sensitivity, prevented ER stress, and enhanced hepatic beta-oxidation, impeding MASLD development in this mouse model even when consuming high energy intake from saturated fatty acids.

Effectiveness of short sprint interval training in women with major depressive disorder: a proof-of-concept study.

Background: High-intensity intermittent training has emerged as an option for treating major depressive disorder (MDD). However, short sprint training (sSIT), an efficient HIIT modality, has not been tested yet for this purpose. The sSIT has been proven to induce the same metabolic adaptations, with the advantage of promoting lower muscle fatigue than other HIIT protocols. Methods: Seventeen adult women diagnosed with moderate/severe MDD were randomly allocated into a sSIT group (n=9) or a control condition (n=8). The sSIT group completed, over two weeks, six 6-10-min sessions which consisted of 3-12 "all out" sprints of 5 s interspersed with low-intensity recovery of 30-45 s. The week before and after the intervention, both groups were evaluated with the Hamilton Depression Rating Scale of 21-itens (HAM-D21), and for physical fitness and incidental physical activity. Results: The sSIT group exhibited significant improvements for HAM-D21 scores (24.6±8.2 vs. 16.8±10.1), maximum aerobic power (140±15 vs. 155±15 W), countermovement jump (13.0±3.4 vs. 14.9±3.1 cm), % of body fatness (32.4±4.4 vs. 29.3±3.8%), and 4-days number of steps (13,626±11,309 vs. 16,643±15,371) after the training period when compared to the control group. Conclusion: Less than 1 hour of a sSIT protocol over two weeks have demonstrated to reduce depressive symptoms, while improving aerobic fitness and body composition, and increasing incidental physical activity in a sample of women diagnosed with MDD.

Sleep Quality in CrossFit: A Cross-Sectional Study.

Objective Based on the relationship between sleep and sports performance, the present study aimed to evaluate sleep quality and excessive daytime sleepiness among adult CrossFit (CrossFit, LLC, Santa Cruz, CA, USA) practitioners and to verify possible associations with intestinal health. Methods This cross-sectional study involved males and females aged ≥ 18 years who had been regularly practicing CrossFit for at least 3 months. This survey used an online questionnaire addressing demographic and socioeconomic data, disease history, dietary characteristics, and questions regarding CrossFit. To assess intestinal health, the ROME IV Consensus Criteria and Bristol Scale were used. The Pittsburgh International Sleep Quality Index (PSQI-BR) and Epworth Sleepiness Scale were used to assess sleep quality. Results A total of 1,090 people (73.3% females) with a mean age of 31.2 ± 7.5 years were included. Considering the diagnosis of constipation, 36.9% of the patients were classified as constipated, especially females when compared with males ( p < 0.001). On the sleepiness scale, 22.4% of the volunteers showed excessive daytime sleepiness, which was also observed more frequently among females ( p = 0.013). In the PSQI-BR, 47.4% of participants were classified as having poor sleep quality (poor sleepers). The overall PSQI-BR score was 5.81 ± 2.85, with no difference between males and females ( p = 0.360). There was a positive correlation between the PSQI-BR global score and a diagnosis of constipation and excessive daytime sleepiness. There was a negative correlation between the stool type on the Bristol scale and the PSQI-BR global score. Conclusion The present study demonstrated that sleep quality was poor among CrossFit users, especially females, which can compromise their training performance.

Effects of high-intensity interval training and its different protocols on lipid profile and glycaemic control in type 2 diabetes: A meta-analysis.

This meta-analysis of randomised clinical trials aimed to compare the effects of high-intensity interval training (HIIT) and its different protocols versus moderate-intensity continuous training (MICT) and/or control on total cholesterol, HDL, LDL, triglycerides, HbA1c levels, and fasting glucose in individuals with type 2 diabetes mellitus (T2DM). The search strategy was performed in PubMed/MEDLINE, Cochrane CENTRAL, EMBASE, Web of Science, Sport DISCUS, and PEDro, until January 2023. A total of 31 studies (1092 individuals) were included. When compared to control, HIIT decreased total cholesterol by -0.31 mmol/L (95% CI -0.49; -0.12), LDL by -0.31 mmol/L (95% CI -0.49; -0.12), triglycerides by -0.27 mmol/L (95% CI -0.33; -0.2), HbA1c by -0.75% (95% CI -0.97; -0.53), fasting glucose by -1.15 mmol/L (95% CI -1.44; -0.86), and increased HDL by 0.24 mmol/L (95% CI 0.06; 0.42). No difference was found in the comparison between HIIT versus MICT for any of the outcomes analysed, however subgroup analysis showed that a moderate-interval (>30s to < 2 min) and moderate-term (>4 to < 12 weeks) HIIT protocol reduced total cholesterol, when compared to MICT. HIIT is able to improve lipid profile and glycaemic control in T2DM individuals, and specific protocols can be recommended for improving total cholesterol levels.

Pre and Post-high-intensity Interval Training Delays Colon Tumor Onset in a Syngeneic Mouse Model.

BACKGROUND/AIM: High-intensity interval training (HIIT) can trigger transient anti-tumor cytotoxicity through the mobilization of natural killer cells (NK cells) and myokines. Yet, the effects of HIIT on tumor development and microenvironment are unclear. MATERIALS AND METHODS: Male C57/BL6 mice were administered either MC38 of syngeneic colon cancer cells or vehicle in a single subcutaneous injection. Before injection, the training group completed four weeks of the HIIT program (progressive swimming training, 3/week, 10-12 min, 4-6% of body weight for overload). Following injection, trained mice continued to exercise for two additional weeks. RESULTS: Pre and post-HIIT training was effective in preventing tumor onset (p=0.0065), maintaining body weight gain, and counteracting splenomegaly by 40% compared to the tumor group. However, HIIT had no impact on suppressing tumor growth, modifying final tumor volume, or significantly changing tumor proliferation (Ki-67), connective tissue content, or DNA double-strand damage detected by phospho-histone gamma-H2AX (γ-H2AX). CONCLUSION: Pre and post-HIIT program is feasible for mice carrying a subcutaneous syngeneic tumor and effective in delaying tumor burden; however, HIIT did not alter colon tumor endpoints.

Acute physiological responses to "recovery intermittent hypoxia" in hiit / Respuestas agudas a la "hipoxia intermitente de recuperación" en el hiit / Respostas fisiológicas agudas à "hipóxia intermitente de recuperação" no hiit

ABSTRACT Introduction: Traditional intermittent hypoxia training improves sport performance after short periods of exposure, but acute exposure to intermittent hypoxia leads to decreased training intensity and technical quality. The solution to overcome these negative effects may be to perform efforts in normoxia and the intervals between efforts in hypoxia, maintaining the quality of training and the benefits of hypoxia. Objective: This study aimed to evaluate the acute physiological responses to hypoxia exposure during recovery between high intensity efforts. Materials and methods: Randomized, one-blind, placebo-controlled study. Sixteen men performed a graded exercise test to determine their maximal intensity and two sessions of high-intensity interval training. The training intervals could be in hypoxia (HRT), FIO2: 0.136 or normoxia (NRT), FIO2: 0.209. During the two-minute interval between the ten one-minute efforts, peripheral oxygen saturation (SpO2), heart rate (HR), blood lactate ([La]), blood glucose ([Glu]) were constantly measured. Results: There were differences in HR (TRN = 120 ± 14 bpm; TRH = 129 ± 13 bpm, p < 0.01) and SpO2 (TRN = 96.9 ± 1.0%; TRH = 86.2 ± 3.5%, p < 0.01). No differences in [La] and [Glu] TRN (4.4 ± 1.7 mmol.l-1; 3.9 ± 0.5 mmol.l-1) and TRH (5.2 ± 2.0 mmol.l-1; 4.0 ± 0.8 mmol.l-1, p = 0.17). Conclusion: The possibility of including hypoxia only in the recovery intervals as an additional stimulus to the training, without decreasing the quality of the training, was evidenced. Level of Evidence II; Randomized Clinical Trial of Minor Quality.

RESUMEN Introducción: El entrenamiento tradicional en hipoxia intermitente mejora el rendimiento deportivo tras cortos periodos de exposición, sin embargo, la exposición aguda a la hipoxia intermitente conduce a una disminución de la intensidad del entrenamiento y de la calidad técnica. La solución para superar estos efectos negativos puede ser realizar los esfuerzos en normoxia y los intervalos entre esfuerzos en hipoxia, manteniendo la calidad del entrenamiento y los beneficios de la hipoxia. Objetivo: Este estudio pretendía evaluar las respuestas fisiológicas agudas a la exposición a la hipoxia durante la recuperación entre esfuerzos de alta intensidad. Materiales y métodos: Estudio aleatorizado, a ciegas y controlado con placebo. Dieciséis hombres realizaron una prueba de ejercicio graduado para determinar su intensidad máxima y dos sesiones de entrenamiento por intervalos de alta intensidad. Los intervalos de entrenamiento podían ser en hipoxia (HRT), FIO2: 0,136 o normoxia (NRT), FIO2: 0,209. Durante el intervalo de dos minutos entre los diez esfuerzos de un minuto, se midieron constantemente la saturación periférica de oxígeno (SpO2), la frecuencia cardiaca (FC), el lactato en sangre ([La]) y la glucemia ([Glu]). Resultados: Hubo diferencias en la FC (TRN = 120 ± 14 lpm; TRH = 129 ± 13 lpm, p < 0,01) y la SpO2 (TRN = 96,9 ± 1,0%; TRH = 86,2 ± 3,5%, p < 0,01). No hubo diferencias en [La] y [Glu] TRN (4,4 ± 1,7 mmol.l-1; 3,9 ± 0,5 mmol.l-1) y TRH (5,2 ± 2,0 mmol.l-1; 4,0 ± 0,8 mmol.l-1, p = 0,17). Conclusión: Se evidenció la posibilidad de incluir hipoxia sólo en los intervalos de recuperación como estímulo adicional al entrenamiento sin disminuir la calidad del mismo. Nivel de Evidencia II; Ensayo Clínico Aleatorizado de Baja Calidad.

RESUMO Introdução: O treinamento de hipóxia intermitente tradicional melhora o desempenho esportivo após curtos períodos de exposição, porém a exposição aguda à hipóxia intermitente leva à diminuição da intensidade do treinamento e da qualidade técnica. A solução para superar esses efeitos negativos pode ser realizar esforços em normóxia e os intervalos entre os esforços em hipóxia, mantendo a qualidade do treinamento e os benefícios da hipóxia. Objetivo: Este estudo teve como objetivo avaliar as respostas fisiológicas agudas à exposição de hipóxia durante a recuperação entre esforços de alta intensidade. Materiais e métodos: Estudo aleatório e one-blinded, com efeito placebo controlado. Dezesseis homens realizaram um teste de exercício graduado para determinar sua intensidade máxima e duas sessões de treinamento intervalado de alta intensidade. Os intervalos de treinamento podem ser em hipóxia (TRH), FIO2: 0,136 ou normóxia (TRN), FIO2: 0,209. Durante os dois minutos de intervalo entre os dez esforços de um minuto, foram medidos constantemente a saturação periférica de oxigênio (SpO2), frequência cardíaca (FC), lactato sanguíneo ([La]), glicemia ([Glu]). Resultados: Houve diferenças na FC (TRN = 120 ± 14 bpm; TRH = 129 ± 13 bpm, p <0,01) e SpO2 (TRN = 96,9 ± 1,0%; TRH = 86,2 ± 3,5%, p <0,01). Sem diferenças em [La] e [Glu] TRN (4,4 ± 1,7 mmol.l-1; 3,9 ± 0,5 mmol.l-1) e TRH (5,2 ± 2,0 mmol.l-1; 4,0 ± 0,8 mmol.l-1, p = 0,17). Conclusão: Evidenciou-se a possibilidade de incluir a hipóxia apenas nos intervalos de recuperação como um estímulo adicional ao treinamento, sem diminuir a qualidade do treinamento. Nível de Evidência II; Estudo Clínico Randomizado de Menor Qualidade.

High-intensity interval training in people with spinal cord injury: a systematic review / Entrenamiento por intervalos de alta intensidad en personas con lesiones medulares: una revisión sistemática / Treinamento intervalado de alta intensidade em pessoas com lesão da medula espinhal: revisão sistemática

ABSTRACT Objective: Analyze the effects of high-intensity interval training (HIIT) on cardiometabolic parameters, and cardiorespiratory fitness to compile the most used HIIT training types in adults with spinal cord injury (SCI). Methods: This is a systematic review of searches performed in the electronic databases PubMed / Medline, Science Direct, and Google Scholar. Studies included I) needed to apply HIIT training II) adults with SCI to analyze III) cardiometabolic aspects and cardiorespiratory fitness. Two independent reviewers selected the articles for inclusion, extracted their data, and assessed their methodological quality. Results: 654 studies were found. Thus, 12 studies, 11 pre- and post-intervention, and one control group (CG) with 106 participants were analyzed. Pre- and post-HIITT intervention results revealed significant improvement in cardiorespiratory fitness and cardiometabolic aspects (VO2peak, LDH, HDL, insulin resistance). In addition, GC results revealed significant improvement in cardiorespiratory fitness observed in the intervention group (HIIT) compared to the moderate-low intensity (GC) group. Seven studies used the arm ergometer as the primary exercise modality. Two studies described functional electrical stimulation (FES) performed with the arm ergometer plus electrical stimulation in the lower limbs. None reported heart rate dynamics during the study period. Conclusion: High-intensity interval training improves physical fitness and cardiometabolic health in adults with SCI. Evidence level II; Systematic Review of level II studies.

RESUMEN Objetivo: Analizar los efectos del entrenamiento interválico de alta intensidad (HIIT) sobre los parámetros cardiometabólicos, fitness cardiorrespiratorio y recopilar los tipos de HIIT más utilizados en el entrenamiento en adultos con lesión medular (LME). Métodos: Se trata de una revisión sistemática, para lo cual se realizaron búsquedas en bases de datos electrónicas PubMed/Medline, Science Direct y Google Scholar. Se incluyeron estudios que I) necesitaban aplicar entrenamiento HIIT en II) adultos con SCI y analizar III) aspectos cardiometabólicos y aptitud cardiorrespiratoria. Dos revisores independientes seleccionaron los artículos para su inclusión, extrajeron sus datos y evaluaron su calidad metodológica. Resultados: De los 654 estudios encontrados, se analizaron 12 estudios, 11 pre y post intervención y 1 grupo control (GC) con un total de 106 participantes. Los resultados previos y posteriores a la intervención HIIT revelaron una mejora significativa en la aptitud cardiorrespiratoria y los aspectos cardiometabólicos (VO2pico, LDH, HDL, resistencia a la insulina). Los resultados de GC revelaron una mejora significativa en la aptitud cardiorrespiratoria observada del grupo de intervención (HIIT) en comparación con el grupo de intensidad moderada-baja (GC). Siete estudios utilizaron el ergómetro de brazo como la modalidad principal de ejercicio. Dos estudios describieron la estimulación eléctrica funcional (EEF) realizada con el ergómetro de brazo más la estimulación eléctrica en los miembros inferiores. Ninguno informó la dinámica de la frecuencia cardíaca durante el período de estudio. Conclusiones: El entrenamiento intervalos de alta intensidad mejora la condición física y la salud cardiometabólica en adultos con LME. Evidencia de nivel II; Revisión sistemática de estudios de nivel II.

RESUMO Objetivo: Analisar os efeitos do treinamento intervalado de alta intensidade (HIIT) nos parâmetros cardiometabólicos, aptidão cardiorrespiratória e compilar os tipos de HIIT mais utilizados no treinamento em adultos com lesão da medula espinhal (LME). Métodos: Trata-se de revisão sistemática, para a qual foram realizadas pesquisas nas bases de dados eletrônicas PubMed / Medline, Science Direct e Google Scholar. Foram incluídos estudos em que I) o treinamento HIIT era aplicado em II) adultos com LME e analisaram III) os aspectos cardiometabólicos e aptidão cardiorrespiratória. Dois revisores independentes selecionaram os artigos para a inclusão, extraindo seus dados e avaliarando a sua qualidade metodológica. Resultados: 654 estudos foram encontrados. Desses, 12 estudos, 11 pré e pós intervenção e 1 grupo controle (GC) com um total de 106 participantes foram analisados. Resultados pré e pós intervenção de HIIT revelaram significante melhora na aptidão cardiorrespiratória e aspectos cardiometabólicos (VO2pico, LDH, HDL, resistência à insulina). Resultados do GC revelaram uma significativa melhoria na aptidão cardiorrespiratória observada no grupo de intervenção (HIIT) em relação ao grupo de intensidade moderada-baixa (GC). Sete estudos usaram o ergômetro de braço como modalidade de exercício primária. Dois estudos descreveram a estimulação elétrica funcional (EEF) realizada com o ergômetro de braço adicionando estimulação elétrica nos membros inferiores. Nenhum relatou a dinâmica da frequência cardíaca durante o período do estudo. Conclusão: O treinamento intervalado de alta intensidade melhora a aptidão física e a saúde cardiometabólica em adultos com LME. Nível de evidência II; Revisão sistemática de Estudos de Nível II.

A Cardiopulmonary Exercise Testing for Prescribing High-Intensity Interval Training Sessions with Elastic Resistance.

This study aims to analyze the agreement of cardiopulmonary variables between a cardiopulmonary exercise test with elastic resistance (CPxEL) and high-intensity interval exercise with elastic resistance (EL-HIIE). METHODS: Twenty-two physically independent participants were recruited. Visit one consisted of conducting a health survey and anthropometric assessment. On visit two, the participants performed CPxEL. After seven days, on visit three, the participants performed EL-HIIE. The CPxEL was carried out on a rubber mat demarcated by lines representing eight stages. The test consisted of alternating back and forth steps against elastic resistance. The increments were performed at a rate of one stage per minute, following a cadence controlled by a metronome calibrated by beats per minute (bpm). The EL-HIIE was performed at the stage corresponding to an intensity of ~85% VO2max, as determined by CPxEL. The EL-HIIE consisted of 10 × 1 min (work):1 min (passive rest), with a cadence of 200 bpm. Cardiopulmonary parameters, heart rate (HR), and oxygen consumption (VO2) were measured during exercise. Bland-Altman was applied to analyze the agreement between the HR and VO2 found in EL-HIIE and the values prescribed by CPxEL (~85-90% VO2max). RESULTS: The HRpeak and VO2peak in the EL-HIIE showed good agreement with the VO2CPxEL and HRCPxEL values, showing an average difference of (-1.7 mL·kg-1·min-1) and (0.3 bpm). CONCLUSIONS: The results of the present study demonstrate the agreement of cardiopulmonary variables between the CPxEL and the EL-HIIE. Therefore, for a more specific prescription of EL-HIIE intensity, CPxEL can be used.

Exercise-Induced Muscle Damage after a High-Intensity Interval Exercise Session: Systematic Review.

High-intensity interval training (HIIT) is considered an effective method to improve fitness and health indicators, but its high-intensity exercises and the mechanical and metabolic stress generated during the session can lead to the occurrence of exercise-induced muscle damage. Therefore, this study aimed to describe, by means of a systematic review, the effects of a single HIIT session on exercise-induced muscle damage. A total of 43 studies were found in the Medline/PubMed Science Direct/Embase/Scielo/CINAHL/LILACS databases; however, after applying the exclusion criteria, only 15 articles were considered eligible for this review. The total sample was 315 participants. Among them, 77.2% were men, 13.3% were women and 9.5 uninformed. Their age ranged from 20.1 ± 2 to 47.8 ± 7.5 years. HIIT protocols included running with ergometers (n = 6), CrossFit-specific exercises (n = 2), running without ergometers (n = 3), swimming (n = 1), the Wingate test on stationary bicycles (n = 2), and cycling (n = 1). The most applied intensity controls were %vVO2max, "all out", MV, MAV, Vmax, and HRreserve%. The most used markers to evaluate muscle damage were creatine kinase, myoglobin, and lactate dehydrogenase. The time for muscle damage assessment ranged from immediately post exercise to seven days. HIIT protocols were able to promote changes in markers of exercise-induced muscle damage, evidenced by increases in CK, Mb, LDH, AST, ALT, pain, and muscle circumference observed mainly immediately and 24 h after the HIIT session.

Effects of high-intensity interval training on lean mass, strength, and power of the lower limbs in healthy old and young people.

Introduction: Whether high-intensity interval training (HIIT) can improve lean mass, strength, and power of the lower limbs in young and older people is still under discussion. This study aimed to determine the effect of HIIT on lean mass, maximal strength, rate of force development (RFD), and muscle power of both lower limbs in healthy young and older adults. Secondarily, to compare the effects of HIIT between dominant vs. non-dominant lower limbs of each group. Materials and methods: Healthy older (n = 9; 66 ± 6 years; BMI 27.1 ± 3.1 kg m-2) and young (n = 9; 21 ± 1 years; BMI 26.2 ± 2.8 kg m-2) men underwent 12 weeks of HIIT (3x/week) on a stationary bicycle. The evaluations were made before and after the HIIT program by dual energy X-ray absorptiometry (DEXA), anthropometry, force transducer and, Sit-to-Stand test. The outcomes analyzed were limb lean mass, thigh circumference, maximal voluntary isometric strength, RFD (Time intervals: 0-50, 50-100, 100-200, and 0-200 ms), and muscle power in both lower limbs. Results: After 12 weeks of HIIT, non-dominant limb (NDL) showed increase in limb lean mass (p < 0.05) but without interaction (time*group). HIIT showed a gain in absolute maximal strength and also when adjusted for thigh circumference in the dominant lower limb (DL) in both groups. The RFD0-200 ms showed differences between groups but without interaction. The RFD0-50 ms of the NDL showed post-training improvements (p < 0.05) in both groups. Only the older group showed differences between DL vs. NDL in most of the RFD obtained post-intervention. In addition, post-HIIT muscle power gain was observed in both groups (p < 0.05), but mainly in older adults. Conclusion: HIIT promotes increases in lean mass, maximal strength, early RFD, and lower limb muscle power in healthy older and young individuals. The differences shown between the DL and the NDL must be analyzed in future studies.

Effect of high-intensity interval training compared to moderate-intensity continuous training on body composition and insulin sensitivity in overweight and obese adults: A systematic review and meta-analysis.

Objective: To compare the effects of high-intensity interval training (HIIT) and moderate-intensity continuous training (MICT) on adults with overweight and obesity. Outcomes, including changes in insulin sensitivity, weight, body mass index (BMI), waist circumference, and body fat, were analyzed. Methods: A systematic literature review was conducted. This review is registered in the International Prospective Register of Systematic Reviews (PROSPERO) under the number CRD42021281899. Clinical trials involving individuals who are overweight and obese and comparing HIIT with MICT effects on insulin sensitivity, weight, BMI, body fat percentage, and waist circumference were included. PubMed, Web of Science, Embase, and Scopus databases were searched using controlled vocabulary and free-text terms related to HIIT, obesity, and overweight. The search included studies published until September 2022. The Rob2 tool was used to assess the risk of bias. The results were presented through meta-analyses that provided summary estimators and confidence intervals. Subgroup analyses were conducted to assess the effect of the risk of bias on the outcomes. This research did not receive any specific funding. Results: Of the 2534 articles, 30 met the eligibility criteria. The intervention duration ranged from 4 to 16 weeks. The observed effects for each outcome were as follows: insulin sensitivity (p = 0.02), weight (p = 0.58), BMI (p = 0.53), waist circumference (p = 0.87), body fat percentage (p = 0.07), body fat mass in kilograms (p = 0.39). The level of evidence obtained was moderate except for waist circumference, which was rated as low. Limitations included heterogeneity in training protocols, measurements, and study duration. Additionally, a risk of bias was identified in these studies. Conclusion: HIIT and MICT did not significantly differ in their effects on weight, BMI, waist circumference, or body fat mass in adults with overweight and obesity. However, a moderate beneficial effect of HIIT was observed on insulin sensitivity. Therefore, further evidence is required to confirm these findings.

High-intensity interval training reduces the induction of neutrophil extracellular traps in older men using live-neutrophil imaging as biosensor.

Neutrophil extracellular trap formation (NETosis) is a mechanism used by neutrophils to capture pathogens with their own DNA. However, the exacerbation of this immune response is related to serious inflammatory diseases. Aging is known to lead to an excessive increase in NETosis associated with various diseases. Under this scenario, the search for strategies that regulate the release of NETosis in older people becomes relevant. High-intensity interval training (HIIT) involves repeated bouts of relatively intense exercise with alternating short recovery periods. This training has shown beneficial effects on health parameters during aging and disease. However, little is known about the potential role of HIIT in the regulation of NETosis in healthy older people. The aim of this study was to evaluate the induction of NETosis by serum from healthy young and older men, before and after 12 weeks of HIIT using healthy neutrophils as a biosensor. HIIT was performed 3 times per week for 12 weeks in young (YOUNG; 21 ± 1 years, BMI 26.01 ± 2.64 kg⋅m-2, n = 10) and older men (OLDER; 66 ± 5 years, BMI 27.43 ± 3.11 kg⋅m-2, n = 10). Serum samples were taken before and after the HIIT program and NETosis was measured with live cell imaging in donated neutrophils cultured with serum from the participants for 30 h. Our results showed that serum from older men at baseline induced greater baseline NETosis than younger men (p < 0.05; effect size, ≥0.8), and 12 weeks of HIIT significantly reduced (Interaction Effect, p < 0.05; effect size, 0.134) the induction of NETosis in older men. In conclusion, HIIT is a feasible non-invasive training strategy modulating NETosis induction. Additionally, the use of neutrophils as a biosensor is an effective method for the quantification of NETosis induction in real time.

Acute effect of interval step exercise versus continuous walk exercise on cardiovascular parameters in hypertensive postmenopausal women: A clinical, controlled, and randomized study.

Aiming the prevention and treatment of hypertension, regular physical exercise has become important to reduce blood pressure. The present experiment compared the effect of interval step exercise with continuous walking exercise on cardiovascular parameters of post-menopausal hypertensive women. The volunteers were submitted to three experimental sessions: control (CO), interval exercise (IE) and continuous exercise (CE), in randomized order. The sessions lasted 120 min and during this period, resting blood pressure was evaluated after 10min of siting rest before exercise, and 30, 40 and 60min of siting rest position after exercise. Heart rate variability (HRV) were estimated at rest before exercise and 30min after exercise. Blood pressure reactivity (BPR) to the Stroop Color-Word test was measured at rest before exercise and 60min after exercise. Twelve women finished the study (59 ± 4 years and BMI of 29.78 ± 4.10 kg/m2). The One way ANOVA showed that systolic blood pressure (SBP) area under the curve over time were lower (p = 0.014) in both exercise sessions comparing with control session. The Generalized estimation equations (GEE) showed that SDNN and RMSSD indices of HRV decreases (p < 0.001) in both exercises session as well, comparing with CO. Maximal SBP during Stroop test were lower after both IE and CE exercises session comparing with CO session. We conclude that interval step exercise can reduce blood pressure responses and improve HRV acutely after its performance and these responses are similar to continuous walking exercise.

Self-selected or fixed: is there an optimal rest interval for controlling intensity in high-intensity interval resistance training?

PURPOSE: This study investigated the effects of different rest interval strategies during high-intensity interval resistance training (HIRT) on cardiorespiratory, perceptual, and enjoyment responses among trained young men. METHODS: Sixteen men experienced with HIRT underwent cardiopulmonary exercise testing and were familiarized with the exercises and HIRT protocol. On the subsequent three visits, interspaced 48-72 h, participants performed HIRT sessions with different rest intervals in a randomized order: 10 s and 30 s fixed rest intervals (FRI-10 and FRI-30), and self-selected rest interval (SSRI). Oxygen uptake (VO2), heart rate (HR), and recovery perception (Total Quality Recovery Scale) were measured during HIRT, while enjoyment responses (Physical Activity Enjoyment Scale) were assessed immediately after the sessions. RESULTS: The VO2 during exercise was greater in FRI-10 than FRI-30 (55% VO2max and 47% VO2max, respectively, p = 0.01), while no difference occurred between SSRI and bouts performed with fixed intervals (52% VO2max vs. FRI, p > 0.05). HR, excess post-exercise oxygen consumption (EPOC), recovery perception, and enjoyment responses were similar across conditions (p > 0.05). CONCLUSION: Exercise intensity was not affected by the rest interval strategy. High exercise intensity was maintained in sessions performed with FRI or SSRI, without negative repercussions on the duration of training sessions and enjoyment responses after exercise sessions.

Comparison of High-Intensity Interval Training to Moderate-Intensity Continuous Training for Functioning and Quality of Life in Survivors of COVID-19 (COVIDEX): Protocol for a Randomized Controlled Trial.

OBJECTIVE: The purpose of this study was to compare high-intensity interval training (HIIT) with moderate-intensity continuous training (MICT) for feasibility, safety, adherence, and short- and long-term efficacy in improving functioning and health-related quality of life in survivors of coronavirus disease 2019 (COVID-19). METHODS: COVIDEX is a two-pronged, parallel-group, randomized controlled trial with an 8-week training intervention. The study participants will be 94 patients aged >18 years, admitted to a specialized post-COVID center. Participants will be randomized to HIIT (4 × 4 minutes of high-intensity work periods at 85% to 90% of peak heart rate) and MICT (47 minutes at 70% to 75% peak heart rate) groups for biweekly sessions for 8 weeks. The participants will undergo 2 phases of supervised training (phases 1 and 2) of 4 weeks each, in a public, specialized, post-COVID center. In phase 1, we will assess and compare the feasibility, acceptability, and short-term efficacy of HIIT and MICT intervention. In phase 2, the long-term efficacy of HIIT and MICT will be assessed and compared regarding function and health-related quality of life. To prevent any expectation bias, all study participants and assessors will be blinded to the study hypotheses. Group allocation will be masked during the analysis. All statistical analyses will be conducted following intention-to-treat principles. IMPACT: This study is the first randomized controlled trial that will compare the feasibility, safety, adherence, and efficacy of the HIIT and MICT intervention programs in this population. The findings will potentially provide important information and assist in clinical decision making on exercise to optimize the benefits of clinical health care in survivors of COVID-19.

Effect of Menstrual Cycle Phase on Fuel Oxidation Post HIT in Women Reproductive Age: A Pilot Study.

Women of childbearing age have variations in substrate oxidation rates that can lead to overweight, type II diabetes, and other conditions that may be associated with metabolic inflexibility and the variations in estrogen concentrations observed during the monthly ovarian cycle. PURPOSE: This study aimed to verify and compare the influence of eight treadmill high-intensity interval training (HIT) sessions on carbohydrate and lipid oxidation rates (CHOox and LIPox, respectively) and intensities of ventilatory anaerobic thresholds (VATs) of women in different phases of the monthly ovarian cycle. METHODS: Eleven irregularly active women performed incremental treadmill exercise testing followed by submaximal work-rate running for 45 min to determine VATs, VO2peak, peak velocity (Vpeak), and substrate oxidation rates, before and after a training period, in different phases of their monthly ovarian cycle (follicular phase group, FL, n = 6; luteal phase group, LT, n = 5). The training period consisted of eight HIT sessions, composed each one of eight sets of 60 s running at 100%Vpeak interspersed by 75 s recovery every 48 h. RESULTS: Our results showed no significant differences in VATs intensities between groups. The comparison between groups showed significant differences in relative energy derived from CHO pre- and post-training of -61.42% and -59.26%, respectively, and LIP pre- and post-training of 27.46% and 34.41%, respectively. The relative energy derived from CHO after the training period was 18.89% and 25.50% higher for FL and LT, respectively; consequently, the relative energy derived from LIPox after the training period was 8,45% and 3.46% lower for FL and LT, respectively. Over the training period, Vpeak was ~13.5 km/h, which produced the relative intensities of ~89%VO2peak e ~93%HRpeak for both groups. CONCLUSION: The monthly ovarian cycle phases promote significant changes in substrate oxidation rates leading to a decrease in CHOox. High-intensity interval training can minimize the differences observed and constitute an alternative intervention.