The effect of intermittent training in hypobaric hypoxia on sea-level exercise: a cross-over study in humans.
ABSTRACT The purpose of this study was to examine the effect of intermittent training in a hypobaric chamber on physical exercise at sea level. Over a 10 day period, 16 male triathletes trained for 2 h each day on a cycle ergometer placed in a hypobaric chamber. Training intensity was at 60%-70% of the heart rate reserve. There were 8 subjects who trained at a simulated altitude of 2,500 m, the other 8 trained at sea level. A year later, a cross-over study took place. Baseline measurements were made on a cycle ergometer at sea level, which included an incremental test until exhaustion and a Wingate Anaerobic Test. Altogether, 12 subjects completed the cross-over study. At 9 days after training in hypoxia, significant increases were seen in maximal power output (.W(max))(5.2%), anaerobic mean power (4.1%), and anaerobic peak power (3.8%). A non-significant increase in maximal oxygen uptake (.VO(2max)) of 1.9% was observed. At 9 days after training at sea level, no significant changes were seen in .W(max)(2.1%), .VO(2max) (2.0%), anaerobic mean power (0.2%) and anaerobic peak power (0.2%). When comparing the results of the two training regimes, the anaerobic mean power was the only variable that showed a significantly larger increase as a result of training at altitude. And, although the differences in percentage change between the two training protocols were not significant, they were substantial for as well as for anaerobic peak power. The results of this study indicate that intermittent hypobaric training can improve the anaerobic energy supplying system, and also, to a lesser extent, the aerobic system. It can be concluded that the overall results of the cross-over study showed predominantly improvements in the anaerobic metabolism at variance with the previous study of our own group, where the relative .VO(2max) and .W(max) increased by 7%.
Article: Changes in heart rate recovery index after a programme of strength/endurance training in hypoxia[show abstract] [hide abstract]
ABSTRACT: Objective: To determine whether twelve sessions of resistance training on lower limbs at sim-ulated 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 CLAVE Hipoxia; frecuencia cardiaca; entrenamiento de fuerza resistencia Valoración de la Frecuencia Cardíaca de Recuperación después de un programa de entrenamiento de fuerza resistencia en hipoxia Resumen Objetivo: Doce sujetos jóvenes físicamente activos se dividieron en dos grupos equilibrados para entrenar en hipoxia (HYP) y normoxia (NOR).Apunts Medicine de l'Esport 01/2012; 47(173):23-29.
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ABSTRACT: Field-based team sport matches are composed of short, high-intensity efforts, interspersed with intervals of rest or submaximal exercise, repeated over a period of 60-120 minutes. Matches may also be played at moderate altitude where the lower oxygen partial pressure exerts a detrimental effect on performance. To enhance run-based performance, team-sport athletes use varied training strategies focusing on different aspects of team-sport physiology, including aerobic, sprint, repeated-sprint and resistance training. Interestingly, 'altitude' training (i.e. living and/or training in O(2)-reduced environments) has only been empirically employed by athletes and coaches to improve the basic characteristics of speed and endurance necessary to excel in team sports. Hypoxia, as an additional stimulus to training, is typically used by endurance athletes to enhance performance at sea level and to prepare for competition at altitude. Several approaches have evolved in the last few decades, which are known to enhance aerobic power and, thus, endurance performance. Altitude training can also promote an increased anaerobic fitness, and may enhance sprint capacity. Therefore, altitude training may confer potentially-beneficial adaptations to team-sport athletes, which have been overlooked in contemporary sport physiology research. Here, we review the current knowledge on the established benefits of altitude training on physiological systems relevant to team-sport performance, and conclude that current evidence supports implementation of altitude training modalities to enhance match physical performances at both sea level and altitude. We hope that this will guide the practice of many athletes and stimulate future research to better refine training programmes.Sports Medicine 07/2012; 42(9):751-67. · 5.16 Impact Factor
Article: The Effect of Intermittent Hypoxic Exposure plus Sea Level Swimming Training on Anaerobic Swimming Performance[show abstract] [hide abstract]
ABSTRACT: An approach which has been proposed as a time efficient variant of the "live-‐high train-‐low" altitude training strategy is that of intermittent hypoxic exposure. The aim of the study was to determine whether 3 weeks of intermittent hypoxic exposure would enhance sea level anaerobic swimming performance. Eight participants (age = 20 + 2 years; height =1.77 + 4.80m; mass = 72.0 + 3.0 kg) took part in the study and were split into two groups: experimental (EXP) and control (CON). For 3 days a week over a 3 week consecutive period, both groups rested for a total of 90 minutes per day in the hypoxic chamber, whilst undergoing their usual training programme. The experimental group rested in a hypoxic chamber at a simulated altitude of 2300m, whilst the control group rested in a hypoxic chamber at sea level conditions. All participants underwent a total of 3 performance tests (100m sprint) 1 week prior to the hypoxic exposure, 2 days post exposure (Post 1) and 9 days post exposure (Post 2). A blood lactate sample was taken at rest, immediately after, 3 and 7 minutes after each time trial. Using a two-‐way repeated measures ANOVA, the results revealed that there was no significant difference in time for 100m performance (p = 0.431), stroke count (p = 0.824) or stroke rate (p= 0.278), but there was a significant increase over time for blood lactate (p < 0.01). This dose of intermittent hypoxic exposure was not sufficient to elicit significant improvements in 100m sprint time in these eight competitive swimmers. Introduction The concept of training at altitude in order to improve sea level performance is now well established and is commonly incorporated into many athletes' training programmes (Morton and Cable, 2005). The rationale for altitude training is that the reduction in inspired oxygen is causally related to haematological, hormonal and metabolic adjustments facilitating improvements in sea-‐level exercise performance (Rodriguez et al. 2007).Journal of Swimming Research. 11/2012; 19(2).