Seguridad y mayor tolerancia al esfuerzo con entrenamiento interválico en comparación con el entrenamiento de intensidad moderada continua en cardiópatas de riesgo cardiovascular muy alto / Safety and improvement in exercise tolerance with interval training vs moderate-intensity continuous training in heart disease patient of very high cardiovascular risk

Resumen Objetivo: Evaluar la seguridad y el efecto del entrenamiento por intervalos de moderada y alta intensidad (EIMI, EIAI) y compararlo con el entrenamiento de intensidad moderada continua (EIMC) en pacientes de riesgo cardiovascular (RCV) muy alto. Método: Estudio cuasi experimental de 81 pacientes que ingresaron al programas de rehabilitación cardíaca y prevención secundaria (PRHCPS); en la estratificación de riesgo, todos los pacientes presentaron ≥ 2 factores de RCV alto. Entrenamiento concurrente: aeróbico supervisado: 2 semanas de entrenamiento de base de EIMC; luego el grupo EIMC con la misma prescripción, EIMI a 3 intervalos de 3' al 70 a 80% de FCR con pausas activas de 3' al 60 a 70% de FCR; EIAI, 3 intervalos de 3' a 80 a 90% de FCR con pausas activas de 3' al 70 a 80% de FCR, entrenamiento de fuerza con tres sesiones semanales de ejercicios isotónicos y una de calistenia e intervención multidisciplinaria. Resultados: 81 pacientes asignados en tres grupos: 61 a EIMC, 13 a EIMI y 7 a EIAI, sin diferencias significativas en las variables epidemiológicas. Hubo ganancias porcentuales en MET-carga de 45%, 60% y 86% (p = 0.17) y carga-vatios de 51, 44 y 48 en EIMC, EIMI, EIAI, respectivamente (p = 0.54). A pesar de no existir diferencias estocásticamente significativas intergrupales, sí se registró una ganancia mayor en MET-carga en el grupo de EIAI. No se observó desenlace adverso en ningún tipo de entrenamiento. Conclusiones: En cardiópatas de riesgo cardiovascular muy alto, el entrenamiento interválico EIMI/EIAI supervisado es seguro, con tendencia a mayor ganancia en tolerancia al esfuerzo (MET-carga) con el EIAI en comparación con el EIMC.

Abstract Objective: Evaluate safety and effects of training at moderate and high intensity intervals (MIIT, HIIT) compared to continuous moderate intensity training (MICT) in heart disease patient with very high cardiovascular risk (CVR). Method: Quasi-experimental study of 81 patients in a cardiac rehabilitation (CR) program, after risk stratification, all patients presented at least 2 factors with high CVR. All patients were provided supervised concurrent training: aerobic: initially 2 weeks MICT. subsequently MICT group with same prescription, MIIT 3 intervals of 3 ‘to 70-80% FCR with active pause exercise of 3' to 60 a 70% FCR, HIIT 3 intervals of 3'a 80-90% FCR with active pause exercise of 3 ‘70 a 80% FCR, resistance training 3 weekly sessions isotonic exercises and 1 calisthenics and multidisciplinary intervention. Results: 81 patients assigned to: 61 MICT group, 13 MIIT and 7 HIIT, no significant differences were observed. Percentage gains were obtained in METs-load 45%, 60% and 86% (p = 0.17) and watts 51, 44 and 48 in MICT, MIIT, HIIT respectively (p = 0.54). Although there are no statistical significant intergroup differences if there is a greater improvement in MET-load in the HIIT group. There was no adverse outcome in any training. Conclusions: In very high cardiovascular risk heart disease patient, supervised interval training (MIIT/HIIT) is safe, with a tendency to greater improvement in exercise tolerance (METs-load) with HIIT compared to MICT.

EFFECT OF MUSCLE FATIGUE AND DEHYDRATION ON EXERCISE INDUCED MUSCLE CRAMP (EIMC) / 体力科学

The purposes of this study were to 1) develop“cramp screening tests”to investigate susceptibility to exercise induced muscle cramp (EIMC) and 2) examine the effect of muscle fatigue and dehydra. tion-rehydration on EIMC using the tests. Twenty healthy male subjects were placed into three groups based on their experience of EIMC ; high (n=4, frequent cramps in daily life), low-medium (n=12, cramps with special conditions such as strenuous exercise), and no cramps (n=4), and performed two cramp screening tests for the toe flexors and hamstrings. The results indicated that the higher the frequency of muscle cramps in daily life, the higher the cramp induction rates in the tests. To investigate the effect of muscle fatigue on EIMC, 15 out of the 20 subjects performed 100 rhythmic isometric (knee joint angle of 90°) or isokinetic contractions (range of motion : 60-120°, flexion : 60°/s, extension ; 300°/s) of the knee flexors in separate days. Susceptibility to EIMC decreased in the exercised muscle after the fatiguing exercises, but significantly increased in the toe of the exercised limb. To verify the effect of dehydration on EIMC, nine out of the 20 subjects were dehydrated to reduce 3 % of body weight by an intermittent sauna exposure and rehydrated by giving the dehydrated amount of plain water. Dehydration significantly increased the susceptibility to EIMC, and rehydration did not contribute to decrease the susceptibility. These results suggest that the susceptibility to EIMC would be estimated by using the tests, and dehydration is associated with EIMC, but muscle fatigue does not seem to be a direct factor for EIMC.