High altitude training - developing an international centre for Sri Lanka: evaluating for the best outcome

Abstract

This article is based on the detailed inception report on technical evaluation, which was presented on request to the Ministry of Sports, Sri Lanka in June 2017, proposing the establishment of a Sports Medicine Human Performance and Research Centre at the planned High Altitude Training Centre (HATC), Nuwara Eliya, Sri Lanka. The report was compiled by the Sports Medicine and Research Evaluation Team at the Faculty of Medicine, University of Colombo and the Project Consultancy Unit, University of Moratuwa in collaboration with international content experts. The objective of this report was to inform the Sports Medicine requirements that should be considered during development of the high altitude training centre in Sri Lanka. This article discusses the scientific basis of altitude training, the global context listing several international centres for altitude training and the Sri Lankan context with the assessment of the environmental suitability and recommendations based on available evidence. 1 Department of Allied Health Sciences, Faculty of Medicine, University of Colombo, Sri Lanka. 2 Queensland University of Technology, Brisbane, Australia. 3 School of Health and Life Sciences, Federation University, Australia, Mt Helen VIC 3350, Australia. 4 Murdoch Sport Science Laboratory, Murdoch University, Perth, Australia. 5 Planning Division, Ministry of Health, Sri Lanka. 6 Project Consultancy Unit, Faculty of Architecture, University of Moratuwa, Sri Lanka. Introduction High altitudes are defined as geographical locations 3000-5500 m above sea level. Different research studies, various professional bodies and institutions worldwide have specific definitions for ‘high altitude’. The consensus statement of FIFA Sports Medical Committee 2008, defines elevations between 0-500 m as ’Near sea level’, above 500 m 2000 m as ’Low altitude’, 2000 m 3000 m as ’Moderate altitude’ and above 5500 m as ’Extreme altitude’ [1, 2]. Training at low-to-moderate altitudes (500-3000 m) has long been used with endurance athletes to enhance subsequent sea level endurance performance or to acclimatise to competition at altitude. This mainly occurs through the elevations in blood parameters and/or other means of improving oxygen transport and utilisation [3, 4]. This phenomenon of metabolic adaptation provided athletes an alternative mechanism to increase endurance, and thereby, their level of performance in sports. This interest in Altitude Training (AT) has grown since the 1968 Olympics in Mexico City (2400 m), when the impact of hypoxia on sport performance became clear [5]. This has revolutionized the training of athletes for competitions since most of elite athletes engaged in individual endurance sports are now using AT [6] and athletes from different ’team sports’ worldwide engage in AT more than ever before. The science behind human body responses to altitudes Human physiological adjustments as a result of exposure to altitude environments have been studied from the 17th century by various scientists. The science behind the response of the body to altitudes at rest is well understood. The environmental hypoxia (low oxygen levels in the inspired air) that is observed in altitudes results in a series of REPORT Correspondence: CR, e-mail: chath_r@yahoo.com.au> Ransinghe C, et al. SLJSEM, 2018, 1: 1 24 physiological adaptations in the body that increases oxygen carriage by blood and utilisation by the muscles [7]. The long term physiological benefits or the adaptations to altitudes is mainly by the increase production of red blood cells in the body through stimulation of erythropoietin hormone, which increase due to low oxygen levels in blood (hypoxaemia). This in turn increases the oxygen carrying capacity of blood and endurance-like performance. Research on body’s response to altitude while exercising, has developed over the recent past. The hypoxic stress may not be the only factor involved in the enhancement of performance during training since other central (e.g., ventilation, haemodynamics or neural adaptations) and/or peripheral (e.g., musclebuffering capacity or economy) factors may also play an important role. A negative aspect to the physiological effects of acclimatization has also been studied extensively. Research studies have identified decrease in the blood flow to skeletal muscles, larger risk of dehydration, depression of immunity from living in high altitudes, possible effects of decrease in the absolute training intensity, decreased plasma production and increased destruction of red blood cells (haemolysis) after returning to low altitudes [8]. This highlights that best practice once training at altitude would need to be informed by research in order to maximize training responses and minimize potential side-effects of chronic hypoxic exposure. Types of altitude training Training that can be completed at altitudes has evolved considerably and can be categorized into three distinct types [4, 9]. 1) Live-high train-high (LHTH) 2) Live-high train-low (LHTL) 3) Live-low train-high (LLTH) These training modalities can be achieved with natural altitude, simulated altitude or a combination of both. The LHTH method involves both living and training at low-to-moderate altitudes to induce positive hematological adaptations. A potential limitation of this technique includes decrease in the aerobic capacity of the person with altitude (1% drop for every 100 m altitude ascent above 1500 m) [10]. This limits training intensities where athletes can’t train at similar high intensities than they would normally do near sea level. The LHTL involves living at high altitude while training at lower elevations. This can be achieved either through travelling between different altitude locations or through the use of artificial means of reducing oxygen delivery to the body, such as use of masks (hypoxicators and portable devices) or living in a low oxygen environments (e.g. nitrogen house, hypoxic chamber). With the LLTH approach athletes breathe hypoxic air during their usual exercise training, while living near sea level. Today, the LHTL intervention is probably recognized as the “gold standard” for maximized normoxic exercise performance gains in athletes [11]. The duration of residence/training at altitudes has also been considered a major factor dictating what is the preferred AT method to implement. Although there is no clear consensus today in the scientific community, in individual athletes, the success of altitude training may require living high enough (>1800 m), for enough hours a day (>12-14 hours/ day), for a sufficient period of time (>15 days), in order to sustain an erythropoietic effect of hypoxia; (~250-300 h) [4]. High altitude illnesses There have been cases during events such as mountain races, athletes may experience very rapid ascent to high altitudes, which places them at high risk for developing altitude illness [12]. At any point 1-5 days following ascent to altitudes 2500 m, individuals are at risk of developing one of three forms of acute altitude illness. Acute mountain sickness (AMS), a syndrome of nonspecific symptoms including headache, lassitude, dizziness and nausea; high-altitude cerebral oedema (HACE), a potentially fatal illness characterised by ataxia, decreased consciousness; and high-altitude pulmonary oedema (HAPE), a non-cardiogenic form of pulmonary oedema resulting from excessive hypoxic pulmonary vasoconstriction which also can be fatal [13]. Risk factors for developing high altitude illness include previous history of high altitude illness, a faster rate of ascent, higher elevation, poor hydration, increased intensity of physical activity, and individual variability [12] . Slow ascent to altitude is the hallmark of prevention for all acute high altitude illnesses. Guidelines recommend that once above 2500 m, altitude should be increased at a rate of 400 m to 500 m per day [14, 15]. Duration of an effective acclimatization also depends on the athlete’s residing altitude and the altitude to which the athlete plans to ascend.