Moderate-intensity constant or high-intensity interval training? Metabolic effects on candidates to undergo bariatric surgery.

BACKGROUND & AIMS: Bariatric surgery is highly effective against obesity. Pre-surgical exercise programs are recommended to prepare the candidate physically and metabolically for surgery-related rapid weight loss. However, the ideal exercise prescription in this population is unknown. This study aimed to compare the metabolic effects of moderate-intensity constant (MICT) vs. a high-intensity interval training (HIIT) program in candidates to undergo bariatric surgery. METHODS AND RESULTS: Twenty-five candidates (22 women) to undergo sleeve gastrectomy aged from 18 to 60 years old were recruited. At baseline, we measured body composition, physical activity levels, grip strength, and aerobic capacity. Further, we assessed metabolic function through glycemia and insulinemia (both fasting and after oral glucose tolerance test (OGTT)), homeostatic model assessment for insulin resistance (HOMA-IR), lipid profile, glycated haemoglobin (HbA1c), transaminases, fibroblast growth factor 21 (FGF21), growth differentiation factor 15 (GDF15), apelin, and adiponectin. Afterward, participants were randomized into MICT (n = 14) or HIIT (n = 11). Both training programs consisted of 10 sessions (2-3 times/week, 30 min per session) distributed during 4 weeks before the surgery. After this, all outcomes were measured again at the end of the training programs and 1 month after the surgery (follow-up). A mixed effect with Tukey's post-hoc analysis was performed to compare values at baseline vs. post-training vs. postsurgical follow-up. Both training programs increased aerobic capacity after training (p < 0.05), but only after MICT these changes were kept at follow-up (p < 0.05). However, only MICT decreased fat mass and increased total muscle mass and physical activity levels (p < 0.05). Metabolically, MICT decreased insulinemia after OGTT (p < 0.05), whereas HIIT increased adiponectin after training and GDF15 at follow-up (both p < 0.05). CONCLUSIONS: Both MICT and HIIT conferred benefits in candidates to undergo bariatric surgery, however, several of those effects were program-specific, suggesting that exercise intensity should be considered when preparing these patients. Future studies should explore the potential benefits of prescribing MICT or HIIT in a customized fashion depending on a pretraining screening, along with possible summatory effects by combining these two exercise programs (MICT + HIIT). CLINICAL TRIAL REGISTRATION: International Traditional Medicine Clinical Trial Registry, N° ISRCTN42273422.

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.

Respuesta fisiológica al test de lanzadera en pacientes candidatos a cirugía bariátrica / Physiologic response to the incremental shuttle walk test in candidates to undergo bariatric surgery / Resposta fisiológica ao teste incremental de caminhada em candidatos a cirurgia bariátrica

Objetivos: la valoración de la tolerancia al ejercicio es clave para prescribir ejercicio en candidatos a cirugía bariátrica. El test de lanzadera (TL) se ha propuesto para este objetivo. Sin embargo, la evidencia que describe el rendimiento y respuesta fisiológica asociados a esta prueba en dicha población es escasa. El objetivo de este estudio fue describir la respuesta fisiológica a la realización del TL en candidatos a cirugía bariátrica. Métodos: este estudio transversal incluyó a 56 participantes. Se midieron factores antropométricos como la edad, peso, estatura y circunferencia de cintura, así como el nivel de actividad física espontáneo. Se valoró el rendimiento en el TL en metros, la respuesta fisiológica asociada en términos de frecuencia cardiaca de reserva (FCR) utilizada, presión arterial sistólica y diastólica, oximetría de pulso, sensación subjetiva al esfuerzo (SSE) y de fatiga de extremidades inferiores, antes y después del TL. Resultados: todos los participantes completaron la prueba sin complicaciones. Caminaron una mediana de 465 metros, equivalente al 61% de la distancia esperada. Utilizaron un 56% de la FCR, mientras que la SSE y fatiga de extremidades inferiores alcanzó valores 7/10 y 6/10 respectivamente. Fueron observadas asociaciones significativas entre el rendimiento en el TL vs factores antropométricos e indicadores de respuesta fisiológica. Conclusión: el TL es una prueba segura para valorar la tolerancia al esfuerzo en candidatos a cirugía bariátrica, la cual induce respuestas fisiológicas asociadas a intensidades moderadas. Se sugiere incluir esta prueba para la valoración de la condición física de estos sujetos.

Objective: Exercise tolerance measurement is key for exercise prescription in bariatric surgery candidates. Thus, the incremental shuttle walking test (ISWT) has been proposed as a useful tool for this purpose. However, reports describing the performance, and related physiological response, in candidates to bariatric surgery are scarce. Therefore, the aim of this study was to describe the physiological response of bariatric surgery candidates to the ISWT. Methods: This cross-sectional study included 56 participants. Anthropometric factors such as age, weight, height, and waist circumference were measured, as well as their spontaneous physical activity levels. Their ISWT performance was recorded, as well as the percentage of heart rate reserve used during the test, systolic and diastolic pressure, pulse oximetry, perceived exertion scale, and lower extremities fatigue, both before and after the ISWT. Results: All participants completed the test without complications. They walked a median of 465 meters, 61% of the expected distance. Heart rate reserve utilization reached 56%, while the perceived exertion rate and lower extremities fatigue reached 7/10 and 6/10, respectively. Moreover, significant associations between the ISWT performance vs anthropometric factors and physiological response outcomes were found. Conclusion: The ISWT is a safe and useful tool to assess exercise tolerance in bariatric surgery candidates, which induces physiological responses associated to moderate effort intensities. We suggest including the ISWT when assessing the physical performance of bariatric surgery candidates.

Objetivo: A medida da tolerância ao exercício é fundamental para a prescrição do exercício em candidatos à cirurgia bariátrica. Assim, o teste incremental de caminhada em vaivém (ISWT) tem sido proposto como uma ferramenta útil para este fim. No entanto, são escassos os relatos que descrevem o desempenho e a resposta fisiológica relacionada em candidatos à cirurgia bariátrica. Portanto, o objetivo deste estudo foi describir a resposta fisiológica do ISWT em candidatos à cirurgia bariátrica. Métodos: Este estudo transversal incluiu 56 participantes. Fatores antropométricos como idade, peso, altura, circunferência da cintura foram medidos, assim como os níveis de atividade física espontânea. O desempenho do ISWT foi registrado, assim como a porcentagem de reserva de frequência cardíaca utilizada durante o teste, pressão sistólica e diastólica, oximetria de pulso, escala de esforço percebido e fadiga de membros inferiores, tanto antes quanto após o ISWT. Resultados: Todos os participantes completaram o teste sem intercorrências. Eles caminharam uma mediana de 465 metros, o equivalente a 61% da distância esperada. A utilização de reserva de frequência cardíaca atingiu 56%, enquanto a taxa de esforço percebido e fadiga de membros inferiores atingiram 7/10 e 6/10, respectivamente. Além disso, foram encontradas associações significativas entre o desempenho do ISWT versus fatores antropométricos e os resultados da resposta fisiológica. Conclusão: O ISWT é uma ferramenta segura e útil para avaliar a tolerância ao exercício em candidatos à cirurgia bariátrica, que induz respostas fisiológicas associadas a intensidades moderadas de esforço. Sugerimos incluir o ISWT para avaliar o desempenho físico dos candidatos à cirurgia bariátrica.

Demographic/anthropometric factors and physiological performance-related parameters associated with the six-minute walk test in bariatric surgery candidates, from Valdivia, Chile / Fatores demográficos/antropométricos e parâmetros fisiológicos relacionados ao desempenho associados ao teste de caminhada de seis minutos em candidatos à cirurgia bariátrica, de Valdivia, Chile / Factores demográficos/antropométricos y parámetros fisiológicos relacionados con el desempeño en la prueba de la marcha de seis minutos de candidatos a cirugía bariátrica de Valdivia, Chile

ABSTRACT The six-minute walk test (6MWT) is widely used to measure functional capacity in special populations. However, the factors associated with its performance in candidates for bariatric surgery are unclear. Therefore, this study aimed to investigate the influence of anthropometric and physiological factors in the 6MWT performance in bariatric surgery candidates. This cross-sectional study included 107 candidates for bariatric surgery. Anthropometric factors considered: gender, weight, height, body mass index (BMI), waist-to-hip, and waist-to-height ratios. Along with distance covered during 6MWT, physiological factors such as ratings of perceived exertion (RPE) and heart rate reserve percentage used (%HRR) were recorded. Among the 107 patients (mean age: 39.6 years), 83 volunteers were accepted to perform the 6MWT. No gender differences were observed in terms of distance covered, %HRR, and RPE during the 6MWT. Moreover, BMI and %HRR explained 21% of the 6MWT distance covered. Furthermore, participants with BMI ≤41.5 kg/m2 walked ~50 meters more than their peers above this level (p=0.05). Interestingly, heart rate increase during the 6MWT was lower than described for healthy populations. BMI and %HRR partially explain the variability of the 6MWT performance in bariatric surgery candidates.

RESUMO O teste de caminhada de seis minutos (TC6) é uma ferramenta amplamente usada para medir a capacidade funcional em populações especiais. No entanto, os fatores associados ao seu desempenho em candidatos à cirurgia bariátrica não são claros. Portanto, o objetivo deste estudo foi investigar a influência de fatores antropométricos e fisiológicos no desempenho do TC6 em candidatos à cirurgia bariátrica. Este estudo transversal incluiu 107 candidatos à cirurgia bariátrica. Os fatores antropométricos incluíram: sexo, peso, altura, índice de massa corporal (IMC) e índices cintura-quadril e altura-cintura. Além da distância percorrida durante o TC6, foram registrados fatores fisiológicos, como sensação subjetiva de esforço (SSE) e a porcentagem de frequência cardíaca de reserva utilizada (% FCR). Dos 107 pacientes (idade média: 39,6 anos), 83 voluntários concordaram em realizar o TC6. Não foram observadas diferenças por sexo em termos de distância percorrida, % FCR e SSE durante o TC6. Além disso, IMC e% FCR explicaram 21% da distância percorrida no TM6M. Além disso, indivíduos com IMC≤41,5 kg/m2 andaram ~50 metros a mais do que seus pares acima desse nível (p=0,05). Curiosamente, os aumentos na frequência cardíaca durante o TC6 foram inferiores aos descritos em populações saudáveis. IMC e %FCR foram fatores que explicaram parte da variabilidade do desempenho da TC6 em candidatos submetidos à cirurgia bariátrica.

RESUMEN La prueba de la marcha de seis minutos (PM6) es una herramienta muy utilizada para medir la capacidad funcional en ciertas poblaciones. Sin embargo, poco se conoce sobre los factores asociados a su desempeño en candidatos a cirugía bariátrica. Ante esto, el objetivo de este estudio fue evaluar la influencia de factores antropométricos y fisiológicos en el desempeño de la PM6 en candidatos a cirugía bariátrica. En este estudio transversal participaron 107 candidatos a cirugía bariátrica. Los factores antropométricos fueron: sexo, peso, altura, índice de masa corporal (IMC) e índices cintura-cadera y altura-cintura. Además de la distancia recorrida durante la PM6, se registraron los factores fisiológicos como la sensación subjetiva de esfuerzo (SSE) y el porcentaje de frecuencia cardíaca de reserva utilizada (% FCR). De los 107 pacientes (edad media: 39,6 años), 83 voluntarios aceptaron realizar la PM6. No se encontraron diferencias por sexo respecto de la distancia recorrida, % FCR y ESS durante la PM6. Además, el IMC y el % FCR explicaron el 21% de la distancia recorrida en la PM6. Y los individuos con un IMC ≤41,5 kg/m2 caminaron ~50 metros más que sus pares por encima de este nivel (p=0,05). Resultó interesante que el incremento de la frecuencia cardíaca durante la PM6 fue más bajo que los reportados en poblaciones sanas. El IMC y % FCR fueron los factores que explicaron parte de la variabilidad en el desempeño de la PM6 en candidatos a cirugía bariátrica.