Changes in heart rate recovery index after a programme of strength/endurance training in hypoxia

Abstract

Objective: To determine whether twelve sessions of resistance training on lower limbs at simulated altitude (2500 m) were efficient to elicit an improvement in heart rate recovery index in the first 3 min of recovery after a maximal jump test. Materials and methods: Twelve young physically active subjects were divided in two balanced groups for training in hypoxia (HYP) and normal oxygen (NOR). The subjects were assigned to each group based on previous test results in the 60 s counter-movement jump test (CMJ60). Results: Both groups performed identical strength training (volume, intensity, character and effort conditions) on the lower limbs (squats, half-squats and jumps) for 4 weeks. Both groups improved the measured parameters in all cases. We analyzed the time course of heart rate during the CMJ60 test and the subsequent 3 min recovery period. HYP group (n = 5) improved the heart rate recovery index as compared to NOR group (Student's t-test) at minute 2 (P = 0.03) and minute 3 (P = 0.05). Conclusions: We conclude that a protocol of resistance training on lower limbs (12 sessions in 4 weeks) at a simulated altitude could improve heart rate recovery index compared to the same training performed at sea level. © 2011 Consell Català de l'Esport. Generalitat de Catalunya. Published by Elsevier España, S.L. All rights reserved. PALABRAS CLAVEHipoxia; frecuencia cardiaca; entrenamiento de fuerza resistencia Material y métodos:Los sujetos fueron asignados a cada grupo en base a los resultados en una prueba previa de salto en contramovimiento de sesenta segundos (CMJ60). Ambos grupos realizaron durante 4 semanas un entrenamiento idéntico de fuerza (volumen, intensidad, carácter y condiciones de esfuerzo) en las extremidades inferiores (squat, half-squat y saltos). Resultados: Ambos grupos mejoraron en todos los casos. Se analizó la evolución temporal de la frecuencia cardiaca durante la prueba CMJ60 y el posterior período de recuperación de tres minutos. El grupo HYP (n = 5) refleja una mejoría del índice de recuperación de la frecuencia cardiaca en comparación con el grupo NOR (prueba t de Student) después de 2 (p = 0,03) y 3 (p = 0,05) minutos de finalizar el test de saltos. Conclusiones: Concluimos que un protocolo de entrenamiento de fuerza resistencia (12 sesiones en 4 semanas) de las extremidades inferiores en altitud simulada podría mejorar el índice de recuperación de la frecuencia cardiaca en comparación con el mismo entrenamiento realizado a nivel del mar.

Strength training under hypoxic conditions

“…In the discussion section, the author's state: “For the first time, we demonstrate a significant resistance‐training‐induced increase in muscular endurance in the HRT group”. This comment fails to take into consideration previously reported, improved endurance capacity after a strength‐endurance‐training program performed in hypobaric (Álvarez‐Herms et al 1 ) and normobaric hypoxia (Manimmanakorn et al 6 ).…”

Effects of systemic hypoxia on human muscular adaptations to resistance exercise training

“…The authors suggest that for endurance athletes wanting enhanced muscular endurance performance, without an increase in body mass that comes with muscle hypertrophy, short explosive resistance training under hypoxia would be more suitable than the protocol employed in our study. We agree with the statement, but would like to add that the explosive resistance training most likely should be of a very low intensity (Manimmanakorn et al 2013 ) or of a moderate intensity if combined with endurance exercise (Álvarez‐Herms et al 2012 ). On the other hand, as uniquely shown in our study, recreational athletes requiring not only gains in muscular hypertrophy and strength, but also an enhancement of muscular endurance, a standard hypertrophy‐inducing resistance training protocol (70% of 1RM) performed under normobaric hypoxic conditions, would be advised.…”

“…We respectfully disagree with this comment and aware of this work. However, these two studies implemented very different training protocols; a strength‐endurance training program of which the resistance training of 15 reps per set would suggest a low‐moderate intensity (Álvarez‐Herms et al 2012 ); a very low intensity (20% 1RM) (Manimmanakorn et al 2013 ) As these protocols would not be expected to increase muscle growth, but not surprisingly had a positive impact on endurance capacity, we did not believe that they were entirely relevant to our findings.…”

Effect of Resistance Training Under Normobaric Hypoxia on Physical Performance, Hematological Parameters, and Body Composition in Young and Older People

“…This assumption is reasoned by higher metabolic stress (Scott et al, 2014(Scott et al, , 2015a(Scott et al, , 2017 triggering functional and structural muscular adaptations (Schoenfeld, 2010(Schoenfeld, , 2013. Even though the exact physiological adaptation processes for RTH are not yet precisely known and understood, it is currently known from 18 international publications on RTH-interventions that this special type of resistance training appears to be partially more effective than resistance training under normoxia regarding the improvement of (i) muscle physiological parameter, (ii) neuromuscular adaptation, (iii) hormonal response, (iv) blood parameter, (v) body composition/body mass, (vi) sprint ability, and (vii) endurance performance/cardiovascular health and fitness (Friedmann et al, 2003;Nishimura et al, 2010;Álvarez-Herms et al, 2012;Manimmanakorn et al, 2013a,b;Álvarez-Herms et al, 2014Álvarez-Herms et al, , 2016Ho et al, 2014b;Kon et al, 2014;Kurobe et al, 2015;Chycki et al, 2016;Inness et al, 2016;Yan et al, 2016;de Smet et al, 2017;Mayo et al, 2018;Morales-Artacho et al, 2018;Ramos-Campo et al, 2018a;Martínez-Guardado et al, 2019).…”