Altitude and endurance training

Abstract

The benefits of living and training at altitude (HiHi) for an improved altitude performance of athletes are clear, but controlled studies for an improved sea-level performance are controversial. The reasons for not having a positive effect of HiHi include: (1) the acclimatization effect may have been insufficient for elite athletes to stimulate an increase in red cell mass/haemoglobin mass because of too low an altitude (< 2000-2200 m) and/or too short an altitude training period (<3-4 weeks); (2) the training effect at altitude may have been compromised due to insufficient training stimuli for enhancing the function of the neuromuscular and cardiovascular systems; and (3) enhanced stress with possible overtraining symptoms and an increased frequency of infections. Moreover, the effects of hypoxia in the brain may influence both training intensity and physiological responses during training at altitude. Thus, interrupting hypoxic exposure by training in normoxia may be a key factor in avoiding or minimizing the noxious effects that are known to occur in chronic hypoxia. When comparing HiHi and HiLo (living high and training low), it is obvious that both can induce a positive acclimatization effect and increase the oxygen transport capacity of blood, at least in 'responders', if certain prerequisites are met. The minimum dose to attain a haematological acclimatization effect is > 12 h a day for at least 3 weeks at an altitude or simulated altitude of 2100-2500 m. Exposure to hypoxia appears to have some positive transfer effects on subsequent training in normoxia during and after HiLo. The increased oxygen transport capacity of blood allows training at higher intensity during and after HiLo in subsequent normoxia, thereby increasing the potential to improve some neuromuscular and cardiovascular determinants of endurance performance. The effects of hypoxic training and intermittent short-term severe hypoxia at rest are not yet clear and they require further study.

Assessment of oxidative stress biomarkers – neuroprostanes and dihomo-isoprostanes – in the urine of elite triathletes after two weeks of moderate-altitude training

“…In addition, arrhythmia is one of the physiological responses to hypoxia exposure, caused by ventilator and circulatory responses that are accompanied by an increase in the sympathetic activity and local vasoregulatory effects. Therefore, these are undoubtedly key mechanisms improving oxygen delivery to tissues [1,35]. The increase in the amount of NeuroPs in urine is also evidence that the hard work involved in elite training results in OS in tissues where DHA is present -like muscle, as well as adipose tissue, rectal epithelium, liver and spleen, heart and cheek, red blood cells, and sperm.…”

“…This suggests that 10-epi-10-F 4t -NeuroP and 10-F 4t -NeuroP may be potential biomarkers of lipid peroxidation physical exercise under hypoxia (low levels of oxygen) at moderate altitude (2320 m altitude). The effects of hypoxia in the brain may influence the training intensity and/or the physiological responses during training at altitude [1]. In cerebral cortex of newborn pigs, an increase in the levels of F 4 -NeuroP and other OS markers, after hypoxia and resuscitation with supplementary oxygen (reoxygenation), was detected [33].…”

“…The OS seems to be linearly related to the altitude: higher altitude leads to greater oxidative challenge to the body [5]. The effects of hypoxia in the brain may influence the training intensity and/or the physiological responses during training at altitude [1]. In addition, previous research indicated that the exercise-induced OS may alter the capacity of oxidation and anti-oxidation of brain tissue [6,7].…”

“…At altitude, exposure to hypoxia is known to influence all functional systems of the body, including the central nervous system (CNS), the endocrine, respiratory, and cardiovascular systems, the blood oxygen-carrying capacity, and morphological and functional adaptations in skeletal muscle [1]. The nervous system is especially vulnerable to reactive oxygen species (ROS)-mediated injury some reasons are that the high oxygen consumption of the brain for high energy needs, that is, high O 2 consumption, results in excessive ROS produced.…”

Effect of Wearing the Elevation Training Mask on Aerobic Capacity, Lung Function, and Hematological Variables

“…Using this method, athletes live at moderate altitude (2,500 m) and train at low altitude (1,250 m) which allows athletes to obtain the benefits of altitude acclimatization and continue to train at high intensities, resulting in improvements of aerobic capacity (VO 2 max), ventilatory threshold (VT) and performance at sea level (Chapman et al, 1998;Levine and Stray-Gundersen, 1997;Levine et al, 1991;Mattila and Rusko, 1996;Roberts et al, 2003;Rusko et al, 1999). It has been suggested that in order to obtain the benefits of acclimatized altitude training the athlete must spend at least 12 hours a day for at least 3 weeks at an altitude of 2100-2500m (Rusko et al, 2004). This exposure to hypoxic conditions stimulates the kidneys to produce erythropoietin (EPO), which increases red blood cell (RBC) production (Paula and Niebauer, 2012).…”