Current Issues
No.48
September 2006
 
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European College of Sport Science Symposium

Environmental Aspects of the Olympic Games –
an Interdisciplinary Approach
At the 2004 Pre-Olympic Congress
“Sports Science Through the Ages”: Challenges to the New Millennium.
6-11 August, Thessaloniki, Greece

Thomas Reilly

 

The environment of the Olympic Games: An Introduction
Abstract
Environmental factors can have an impact on performance in major sports tournaments. The history of the modern Olympic Games illustrates how environmental aspects influence the outcomes. Such factors have included air quality (St Louis), pollution (Los Angeles), altitude (Mexico), heat (Rome), for example. Travel schedules and jet-lag syndrome were considerations for most nations competing in Sydney 2000, due to the disharmony between local time and “body clock time” after arrival in Australia. Acknowledging the potential for degrading competitive performance, many competitors prepare coping strategies by acclimatisation, acclimation or behavioural means. Weather conditions are unpredictable well in advance and can deviate substantially from average climatic data. Air ions and electric storms may have differential effects on competitors and spectators. Contemporary athletes use projections for Athens 2004, targeting heat and pollution as potential stressors. A range of pollutants is also relevant to consider for Beijing, 2008. Ecological issues have influence also, notably in the legacy left behind for host cities.
Key words: Air quality, altitude, heat, pollution, weather.

An Interdisciplinary Approach
Environmental factors have been relevant considerations in the modern Olympic Games since the reinstallation of the Summer Olympics in 1896. Physiological stressors have featured most prominently according to climatic and local conditions. The history of the Olympic Games is marked by examples of how performances are influenced by environmental variables. In the events of the first half of the 20th Century, little was done to take possible environmental extremes of heat into consideration when planning the competitive schedule (4).
The modern Olympics have grown in scale as well as appeal. Hosting the Games affords huge benefits for the organising nation, usually acquiring a legacy of resources and facilities (and sometimes debt) for its own community. The venues and installations change the local landscape in a way not otherwise possible. The local infrastructure is transformed in a major way to represent a huge economic investment for the future. The global appeal of the Games raises its own pressures for related commercial applications. Inevitably, there is a question about the Summer Olympics (and Paralympic Games) as to whether its scale has outstripped its ideals.
These considerations provide a background for treating environmental issues in an interdisciplinary framework. The environment is interpreted liberally for this purpose. Broad ecological questions may be raised alongside known effects on athletes interacting with the Olympic environment. In order to demonstrate the relevance of discrete environmental stresses, some examples are first given from previous Games. These include heat, altitude, travel stress and air pollution.

Heat
It is clear that performance in events that entail high heat storage may be degraded in hot conditions. Stresses are accentuated when high relative humidity impairs evaporative heat loss. A radiant heat load may further accentuate the strain on the athlete.
There are may instances of torrid conditions prevailing at the Olympic Games, most notably in the men’s marathon. The event at Paris in 1900 has been described as the “hottest Olympic marathon in history” (3). Race-time temperature was reported as between 35ºC and 39ºC. The extremely hot spell was a continuation of what had been a very warm summer throughout France that year. Of the 16 starters, only seven finished the course which at this time was over a distance of 40.26 km.
There have been later instances of heat influencing performance of Olympic competitors. Acknowledging the potential for negative impact on performance, many athletes prepare coping strategies by using warm-weather camps to gain the benefits of physiological acclimatisation. Such benefits may also be acquired by periodic use of environmental chambers for simulating hot conditions, the process being referred to as acclimation (5). There is also something to be gained from experiencing the hot conditions (even if there is insufficient exposure time for physiological acclimatisation) so that the athlete may devise a strategy to cope in competition.
Projections for climatic conditions utilise meteorological databases which may differ in detail from the competitive locations. Weather conditions are inherently variable, are not highly predictable well in advance and can at any time vary from the average climatic data provided by meteorological sources. Nevertheless, sports science support programmes utilise climatic data to prepare their athletes for exercise in the heat. It is likely that the vast majority of competitors at the 2004 Olympic Games will have benefited from sport-specific advice about how the environment in Athens might impact upon their performance.

Altitude
Altitude is a common feature of the Winter Olympics, the winter sports being associated with mountainous environments. The single instance of altitude stress at the Summer Olympics was in Mexico, 1968. The results from the Games demonstrated how performances in events largely dependent on the oxygen transport system were impaired. In contract, the reduced air density at altitude helped to enhance performance in sprint races of up to an including 400 m and in the horizontal jumps (see Table 1).
All medallists in track-and-field at the Mexico Olympics in events over 800 m and longer were either born or had trained at altitude. Subsequently attention shifted from how to cope with competing at altitude to exploiting the physiological adaptations to altitude in order to aid performance at sea level. This change in emphasis has led to the widespread use of altitude training camps in preparation for major tournaments. The practice is now adopted across a range of sports including swimming and rowing as well as running and cycling.
The use of altitude as a training stimulus has been extended to incorporate altitude chambers located at sea-level. These may be the so-called “altitude huts” or normobaric hypoxic chambers. Commercially available mobile simulators alter the inspired oxygen tension to allow exercise hypoxia to be experienced. Another resource is represented by the hypoxic tents which allow the athlete to sleep in an enclosed environment with reduced partial pressure of the oxygen being breathed in. This places emphasis on habitual activity and living at altitude rather than training in it. In view of the fact that the absolute exercise intensity is usually reduced at altitude, an alternative strategy that is advocated for athletes is to live for sojourns at altitude but return periodically to lower levels in order to maintain the quality of training (2).

Travel
Contemporary elite sport entails frequent travel, often over long durations and distances. Indeed competing on a global basis and inter-continental travel are lifestyle features of top performers. Major tournaments are dispersed throughout the world so that the personal attraction of visiting foreign countries is often tempered by the disruption and inconvenience associated with the trip.
Recent Olympic Games have forced European athletes in particular to consider their itineraries carefully. The summer Olympics of 1996 entailed travel across multiple time-zones westward whereas the Sydney Games required a greater displacement in an easterly direction. The Winter Olympics in Nagano 1998 and Salt Lake City in 2002 also highlighted the need for the European national teams to possess a travel strategy. A similar situation prevails for European countries competing in Beijing 2008, or travelling to China beforehand for the purpose of a “dry run”.
Travel strategies separate the hassle of travel and associated travel fatigue from the desynchronisation of the body clock due to the mismatch between the new local time and the body’s circadian rhythm. The disruption is characterised by the syndrome of jet-lag (6). Whilst the body clock is readjusting gradually to the new time zone, performance can be affected. Pharmacological means of accelerating the adjustment have proved to be less effective in athletes than have behavioural methods (1). Exercise and training can play a role but lifestyle factors are critical.

Air Quality
A concern in urban areas is the quality of the air the inhabitants breathe in. The level of pollution has been a consideration at Olympic Games venues in the past, notably Mexico in 1968 and Los Angeles in 1984. Yet evidence of air quality affecting competitors is available from the Summer Olympics 100 years ago.
The marathon course at St. Louis in 1904 was held over a rural road surface. The runners were preceded by the new generation of motor cars, scattered haphazardly amongst them (3). The clouds of dust generated by the cars practically suffocated the runners moving in their wake. Such lack of concern for the athletes was characteristic of sports spectacles at this time.
Many teams visiting Athens before the 2004 Games have been able to acquire their own data close to competitive venues for the concentration of atmospheric pollutants. Athens is built on a basin, surrounded on three sides by mountains and open to the sea. The topology and industry in the basin and surrounding plains result in very high pollution levels. The 90th percentile values shown in Table 1 demonstrate how Athens is inferior to London for a range of environmental pollutants. These include ozone, nitrogen dioxide, particulate matter less than 10 microns in diameter (PM10s) and black smoke. The likelihood of vulnerable individuals such as asthmatics being adversely affected in the environment of Athens has been an issue with medical staff of competing teams.
The vagaries of climate place some sports at risk from the weather. Swimming in open pools is halted in electrical storms. Wind conditions may also prevent some sports being held or at least disrupt performance. The Meltini wind funnels down from the Balkan mountains over Athens when there is a thermal low over nearby Turkey. Sailors, triathlon swimmers and rowers must learn how to deal with it, as must the archers.

Overview
The global appeal of the Summer Olympics has never been more marked. It is estimated that four billion people will have watched the Games being transmitted on television. During the 16 days of competition, the attention of the international media is focused on Athens and the Olympic Games.
Individual environmental factors will be dealt with as they arise by participants, prepared in advance with sports-specific support programmes. In many cases, support staff as well as competitors are exposed to environmental influences and must also be ready to cope. There are then more telling questions to be addressed with respect to the context of the Games overall. These embrace elements of legacy and economics, culture and philosophy, materialism and ecology. In the changing milieu, it is appropriate to consider again the relevance of the Olympic ideals to the contemporary environment.

References
(1) Atkinson, G., Drust, B., Reilly, T. and Waterhouse, J. (2003). The relevance of melatonin to sports medicine and science. Sports Medicine, 33, 809-831.
(2) Levine, B. (1995). Training and exercise at high altitudes. In: Sport, Leisure and Ergonomics, pp. 74-92. London: E. and F.N. Spon.
(3) Martin, D.E. and Gynn, R.W.H. (2000). The Olympic Marathon: The History and Drama of Sport’s Most Challenging Event. Champaign, Ill: Human Kinetics.
(4) Peiser, B. and Reilly, T. (2004). Environmental factors in the Summer Olympics in historical perspective. Journal of Sports Sciences, 22 (in press).
(5) Reilly, T. and Waterhouse, J. (2005). Sport, Exercise and Environmental Physiology. Edinburgh: Elsevier.
(6) Waterhouse, J., Reilly, T. and Atkinson, G. (1997). Jet lag. Lancet, 350, 1611-1615.

Table 1. Winners of men’s event in track and field: Mexico Olympics

Table 2. A comparison of environmental pollutants in Athens and London. Data presented are 90th percentile values in parts per million.


Heat
Bengt Saltin
The Copenhagen Muscle Research Centre
University of Copenhagen
Copenhagen
Denmark

Abstract
Hot conditions impose strain on the cardiovascular system, which is accentuated by dehydration. With reductions in cardiac output to the active muscles, performance is adversely affected. Exhaustion seems to occur at a common body temperature, implicating a thermoregulatory limiting factor. Attention is shifted to mechanisms within the brain that are associated with the exhausted state.

Key words
Dehydration, maximal oxygen uptake, pre-cooling, skin temperature

The basic issues
Intense exercise in the heat implicates three basic issues:-
  1. Exercise generates heat amounting to about 80% of the energy turnover.
  2. The transport of this heat from the body’s core to its skin puts an extra demand on the cardiovascular system.
  3. There is need to maintain skin temperature as low as possible, via sweating and the consequent disturbed water/electrolyte balance.
Exercise for 120 min at 70-75% O2 max induces the same skin temperature as exercise at 80-85% O2 max. Both muscle temperature and core temperature are increased as a function of the higher exercise intensity.
Skin temperature is influenced by the ambient air temperature rather than by exercise. The rise in skin temperature is steeper for rest compared with exercise as the air temperature increases.
The responses of skin and core temperatures for different environments are shown in Table 1. At 40oC the normal gradient from the body to the environment is reversed as the ambient temperature exceeds body temperature.
The consequence of a high skin temperature when exercising at 85-90% O2 max is that the difference between core and skin temperatures decreases with elevations in ambient temperature. A gradient of 7.5oC at 20oC is reduced to 5oC at 30oC, 2.5oC at 35oC and 0-0.5oC at 40oC. Skin blood flow increases correspondingly from 3-4 l.min-1, 5-6 l.min-1, 7-8 l.min-1 and maybe > 8 l.min-1.
The rise in core temperature is reduced during a 9-day period of acclimatization. The sweat rate is increased and at 35oC the rate of sweat loss may approach 3 l.h-1.
Two questions follow:
  1. Can the athlete drink as much as is lost?
  2. What are the bodily effects of an accumulated dehydration?
The maximal fluid intake is in the range 1-1.5 l.h-1, slightly more in exceptional cases. This means a deficit is likely to occur. This deficit increases the rate of rise in body temperature and adds to the cardiovascular strain.
The bodily effects are complex and involve haemodynamics, fuel supply to the active muscle and brain mechanisms. In many cases dehydration is combined with heat stress so thermoregulatory limits to exercise performance may prevail.

Effects on performance
A rise in body temperature will contribute to a reduction in the level of performance and cause fatigue. A water-perfused jacket can alter the rate of rise in body temperature from 0.10 to 0.05oC.min-1.
The rate of increase in body temperature is illustrated in Figure 1 for two different air temperatures (3). Performance of high-intensity exercise was terminated earlier at the high temperature, the final muscle temperature being similar for the two conditions.
Hyperthermia also causes a reduction in cardiac output. As oesophogeal temperature increases, there is a corresponding increase in heart rate and a reduction in stroke volume. Besides affecting cardiovascular haemodynamics, hyperthermia and dehydration influence oxygen and fuel delivery to active skeletal muscle and their utilization by active muscle.
The effects of dehydration were isolated in the study of Gonzalez-Alonso et al. (1). The environmental conditions were 35oC and 40% relative humidity. The power output of 210 W represented 60% O2 max. Two trials were compared:-
  1. Progressive dehydration until fatigue;
  2. Euhydration with the same exercise duration.
Cardiac output was maintained with euhydration, as was mean arterial blood pressure (Figure 2a), in contrast to the falls occurring with dehydration. The drop in cardiac output with dehydration affected the distribution of blood to different tissues (Figure 2b). Blood flow to the legs was reduced relative to euhydration, as were blood flow to other tissues and forearm blood flow.
The decreased leg blood flow does not impair the delivery of the required oxygen, glucose and FFA, or the removal of lactate. Leg O2 , glucose uptake and FFA uptake are not drastically altered. Skeletal muscle glycogen utilization, lactate production and PCr degradation are elevated with dehydration (see Figure 3).

Exhaustion
The exercise time to exhaustion seems to depend on the core temperature reached. Observations on 10 subjects displayed a range from 40-70 min for time to exhaustion. A feature of the data was that there was a common core temperature around 40.5oC at the termination of exercise.
Brain temperature and metabolism may be linked with the process of fatigue and eventual exhaustion (see Figure 4). Exercise hyperthermia causes brain temperature to rise. Corresponding increases in a/ß waves lead to decreases in arousal and voluntary activation (Figure 5). Perceived exertion is elevated and fatigue is promoted.
Brain oxygen extraction increases during high-intensity exercise to fatigue. The a-vO2
difference reaches a similar level in hyperthermia compared to normal conditions but fatigue occurs earlier (Figure 6). A similar pattern is evident in oxygen extraction across exercising legs.
After exercise, there is an increase in brain O2. Both a-vO2 difference and global brain O2 are elevated in heat stress compared to normal conditions (Figure 7). In contrast to the exercising legs, the brain possesses a large oxygen reserve at the point of exhaustion which appears to secure the brain against reductions in systemic delivery of oxygen (4).

Adjusting body temperature
Body temperature may be altered experimentally by pre-cooling or pre-heating. Immersion in water at 18oC was compared to responses to 37oC and 41oC. Air temperature was 40oC and exercise at 240 W corresponded to 60% O2 max (3).
Exhaustion occurred at the same oesophogeal temperature and the same muscle temperature in each condition. Mean skin temperature on termination of exercise did not differ between conditions. Performance was reduced in time by about 20 min with pre-heating and extended by about the same time with pre-cooling (Figure 8).
Is fatigue due to insufficient skeletal muscle ATP production? Data from Gonzalez-Alonso et al. (2) indicate that stores of PCr and ATP are still adequate when fatigue occurs with dehydration (see Figure 9).
Muscle, oesophogeal and femoral blood temperatures stabilize during sustained exercise or show a small increase when subjects are euhydrated. This trend contrasts with dehydration, where all these temperatures continue to increase. Hyperthermia, whether subjects are euhydrated or dehydrated, induces the highest oesophogeal and skin temperatures (5). Performance is extended when dehydrated if ambient temperature is normal, and prolonged further in euhydration-normal compared to exercising in heat (see Figure 10).
Heart rate is increased with hyperthermia, whether euhydrated or dehydrated. There is a corresponding reduction in oxygen uptake at maximal exercise. Heat stress clearly impairs O2 max and has consequences for performance. These findings support the view that fatigue during maximal exercise is largely associated with the failure of the heart to maintain cardiac output and the delivery of oxygen to the skeletal muscle.

References
  1. Gonzalez-Alonso, J., Calbet, J.A.L. and Nielsen, B. (1998). Muscle blood flow is reduced with dehydration during prolonged exercise in humans. Journal of Physiology, 513, 895-905.
  2. Gonzalez-Alonso, J., Calbet, J.A.L. and Nielsen, B. (1999a). Metabolic and thermodynamic responses to dehydration-induced reductions in muscle blood flow in exercising humans. Journal of Physiology, 520-577-589.
  3. Gonzalez-Alonso, J., Teller, C., Andersen, S.L., Jensen, F.B., Hyldig, T. and Nielsen, B. (1999b). Influence of body temperature on the development of fatigue during prolonged exercise in the heat. Journal of Applied Physiology, 86, 1032-1039.
  4. Nybo, L. and Nielsen, B. (2001). Middle cerebral artery velocity is reduced with hyperthermia during prolonged exercise in humans. Journal of Physiology, 534, Part 1, 279-286.
  5. Nybo, L., Jensen, T., Nielsen, B. and Gonzales-Alonso, J. (2001). Effects of marked hyperthermia with and without dehydration on O2 kinetics during intense exercise. Journal of Applied Physiology, 90, 1057-1064.


Table 1. Responses of skin and core temperature for different environments. Values are in o C



Figure 1. Rate of increase in body temperature for different air temperatures.


Figure 2. Cardiac output, mean arterial pressure (2a) and blood distribution (2b) during euhydration and dehydration.

Figure 3. Muscle glycogen utilization and lactate production due to dehydration.
Figure 4. Brain temperature at exhaustion.

Figure 5. Schematic model of fatigue during exercise in the heat.

Figure 6. Arterio-venous oxygen difference across the brain in dehydration.

Figure 7. Global brain oxygen uptake during dehydration.

Figure 8. Effects of pre-cooling and pre-heating on exercise performance.

Figure 9. Stores of PCr and ATP at the point of fatigue during dehydration.

Figure 10. Performance during exercise in the heat.






The Use of Altitude Training – Possible Reasons for
Benefit and Failures
Ulrich Hartmann
Technical University of Munich
Faculty of Sport Science
Department for Theory and Practice in Sport
Munich
Germany

Abstract
Training at moderate high altitude (HA; 1800 to 2400 m) is one of the few possibilities available to increase the performance more than by the normally given circumstances. To estimate the positive (or negative) effects of training at HA, personal experiences from the point of view of a direct monitoring of training play an important role. Besides the general difficulties of estimating the (positive/negative) effect of training at HA, only few objective data from training practice with top class athletes are available. The effect of training at HA with the goal to improve performance capacity in endurance sports is still under discussion in the sports sciences [2, 3].
In discussing positive or negative effects of high altitude, we have to separate out: 1. General effects of adaptation during or after exposure to high altitude, which give an unspecific benefit. 2. Positive (or negative) training effects which can be similar during training at high altitude or at sea level; additional to this outcome, the training at high altitude can be influenced in a positive (or negative) way. 3. Effects and benefits of training which can be caused only by a stay under high altitude conditions. In most of the studies no differentiation has been made between these aspects, which makes it difficult to interpret under isolated points of view the benefits and / or failures of a stay under HA conditions. Besides these facts, there is the problem of interpreting those effects of a continuous stay versus a regular intermittent hypoxic exposure (LH – TL: Live high, train low; LL – TH; live low, train high) or even more so the effects of several new altitude training strategies like a) normobaric hypoxia via nitrogen dilution (nitrogen apartment), b) supplemental oxygen, c) hypoxic sleeping devices, and d) short-term intermittent hypoxic exposure.
Under general aspects, it should be helpful to outline the benefits of a permanent stay at HA under the aspects of an individual positive-responding athlete. According to these results, an increase of the total blood volume (BV) and a higher capacity for the transport of oxygen can be anticipated [1, 4, 5, 6]. The consequences of this effect can be interpreted by means of an approximation equation. Besides that, the maturation of the reticulocytes (RET) and their increase show a great individual variability (between 10% and 250%); the intra-individual variation in a later study (40% compared to 150% in one athlete) has probably a great influence for the individual increase in BV. The increase in BV is the basis for a positive development of performance during and after a training period at HA.
Therefore a calculation can be provided, focusing on the resulting effect of a higher transportation capacity which is caused by an increase of red blood cells in combination with a higher BV. As long as those effects are generating a systematic benefit in athletes responding positively (e.g. in many members of an elite rowing team) this seems to be at least an indication of a positive aspect of a prolonged or permanent stay at HA. For an intermittent stay or for the other new altitude training strategies (see above), consistent evidence cannot be shown as regular effects in top athletes.
Another influencing and probably the most important factor with regard to the benefit of a stay under hypoxic conditions is the stress presented to the muscle cell, possibly yielding a misleading adaptation of the muscle cell by an (inadequate) load of the training content. Therefore it should be necessary to focus more on individual aspects of the average volume and intensity in the total amount of training of athletes in middle-distance sport events [2]. Referring to our own findings, the intensities during a HA-training camp were significantly different. In particular, a medium to high intensive training (“speed training”) often did not lead to the anticipated long-term training effect or decreased the power output over a given period of time. Although dominant and solely not a specific problem under HA conditions, it seems to be one of the general problems of muscular mal-adaptation which can be negatively fortified under HA conditions, theoretically independent of which altitude training strategies have been chosen. It includes consideration of the actual subjective perceptions and their biological influences on the sport practitioner and incorporation of the traditional points of view (e.g. for periodization).

References
[1]. Ekblom et al. (1972): J. Appl. Physiol. 33, 175-180
[2]. Hartmann & Mader (1999): In: Zeitschrift für Angewandte Trainingswissenschaft (ed), 6, 1, 72–105
[3]. Levine & Stray-Gunderson (1997): J. Appl. Physiol. 83, 102-112
[4]. Luft U. (1941): Ergebn. Physiol. 44, 256-312
[5]. Rost et al. (1975): Sportarzt und Sportmedizin 26, 137-144
[6]. Williams at al. (1973): Med. and Science in Sports 5, 181-186




The lifestyle of current elite athletes: coping with jet lag
Benjamin J Edwards
Research Institute for Sport and Exercise Sciences
Liverpool John Moores University
Henry Cotton Building
15-21 Webster St
Liverpool
L2 3ET
UK


Abstract
International travel is an essential part of the lives of elite athletes, both for purposes of competition and training. Long-haul flights entail crossing multiple time zones, and this causes jet lag, due to disruption of the normal circadian rhythm. Various pharmacological and behavioural approaches have been used to reduce some of the effects of jet lag in sports performers. This overview focuses on strategies used for the Sydney summer Olympics 2000 (10 time zones to the east from the UK), and looks forward to the Beijing 2008 Olympics (8 time zones to the east from the UK). Travel fatigue lasts for only a day or so, is associated with the conditions of the journey (such as the cramped nature of the seating), anxiety about travel, and disruption to the individual’s daily routine and can be separated from the jet lag phenomenon. For those who fly across multiple time zones the effects associated with jet lag are longer lasting, and can reduce motivation to train effectively and impact negatively on performance. The severity and duration of these problems depend on the direction of flight (eastwards or westwards), the number of time zones crossed, and the strategies used to alleviate them. Behavioural solutions for dealing with jet lag involve attention to lifestyle and activity. These methods are preferable to pharmacological means of treating the syndrome. There remains the issue of athlete compliance with any travel strategies, and a systematic educational programme can assist in securing acceptance of any recommendations.
Key words: Behaviour, pharmacology, promoting readjustment, time-zone transitions.

Introduction
Circadian rhythmicity in human physiology has been extensively reported. The internal timing mechanism that mediates this rhythm (the body clock) is located within the anterior of the hypothalamus in the suprachiasmatic nucleus (SCN). The purpose of circadian rhythms is to prepare the body for waking in the light and for sleeping when it is naturally dark. Temporal isolation studies, wherein subjects are kept in caves or isolation chambers and in conditions of a constant environment, have shown that one of the inherent characteristics of the body clock is that it free-runs with a period of ~24.5 hours, so it tends to become phase delayed. This inexact timing mechanism is set to an exact 24-hour day by so-called zeitgebers (time givers); these include the light-dark cycle, the sleep-wake cycle, rhythms in socialisation, feeding and, possibly, based on some recent evidence, rhythms of activity and exercise.
Jet lag is caused by the sluggish readjustment of the circadian timing mechanism to the new environment. Table 1 illustrates this adjustment for a flight from the UK to Beijing, China (8 time zones eastwards). Other explanations for jet lag include 1) the hassle of the flight, 2) the new lifestyle, food and culture at the destination, 3) the excitement of attending important events, and 4) the length of the flight. However, jet lag can be induced in an isolation chamber (where no travel has been undertaken), is found after returning home back to a normal routine, and its severity is related to the number of time zones crossed, not the flight length. The symptoms of jet lag include the following: fatigue; sleep disturbance (either the inability to get to sleep or an earlier waking time); inappropriately timed hunger or loss of appetite; losses of concentration and drive; and headaches. The net result is a likely decrease in training effect and performance.
How long does it take to get over jet lag? Unlike travel fatigue, which an individual normally takes less than 24 hours to recover from, recovery from jet lag depends on the direction of travel and the number of time zones crossed. Generally, symptoms are more severe and readjustment takes longer the greater the number of time zones involved. Eastward travel is less well tolerated than westward, due to the inherent property of the body clock to run slightly slow. Further, after an eastward journey across 10 time zones, current guidelines suggest that, for the purposes of the use of light as a readjustment strategy, it should be treated as a transition of 14 hours to the west. This tendency for the body clock to adjust by a delay rather than an advance after crossing 10-12 time zones in an easterly direction (where destination time is advanced by 10-12 hours with regard to departure time) is termed an antidromic effect.
There is some evidence that older individuals, who are generally less fit, take longer to readjust than younger, fitter individuals (9). This superiority is not necessarily the case in well-motivated and experienced travellers (10).
The problems of jet lag can be reduced and managed by suitable planning before the flight, actions during it, and after arrival at the destination. Many Olympic squads are given formal advice, normally in the form of a booklet as a complement to personal counselling. In the case of the Great Britain Olympic team (Team GB), this advice was the culmination of two years research, in which a “dry run” was conducted the year before the 2000 Games, and each athlete who participated received a feedback report on his/her adjustment. This targeting and specific educational programme prior to the Games led to a good compliance of staff and athletes at the preparation camp in the Gold Coast (Australia), and identified those individuals who had severe symptoms and a slower than average rate of adjustment.

Before the flight
For complete adaptation, current advice suggests that athletes should schedule their arrival well in advance of competition, allowing one day for each time zone travelled to the west and 1.5 days for each time-zone travelled in an easterly direction (4). This allowance may be an overestimation and would be impractical, as it would require an athlete travelling from the UK to arrive 15 days prior to the 2000 Games. The athletes spend longer than this period at the “preparation camp”. It has prompted a more realistic suggestion of leaving one day for each time zone crossed in either westward or eastward journeys (9).

Travel times
Some of the factors that can be changed relatively easily are the time of flight departure, and hence time of arrival, and the decision whether or not to incorporate a stopover to break up the journey. Arriving as close to night-time in the new time zone as schedules allow promotes adjustment indirectly due to the accumulation of fatigue during the flight; this tactic aids sleep during the first night-time at the destination, and the sleep-wake cycle acts as a zeitgeber. If the journey (such as one from the UK to the East coast of Australia) is broken up, with a stopover in Singapore for a few days, this break aids adjustment at the final destination, as it gives the body clock a chance to adjust partially when exposed to the environment at the place of stopover. In practice, this break in the journey involves extra hassle for the athlete in terms of maintaining quality of training. Also, it could add complications such as heat and humidity in the stopover environment, and these present their own problems for the athlete.

Pre-adjustment strategy
Generally, adjustment of sleep-wake habits prior to the flight could in theory begin to alter the normal circadian rhythm in the desired direction prior to departure. This strategy involves sending the athlete to bed earlier and getting him/her up earlier for an eastward journey, and to retire and rise later for a westward journey. The strategy for a westward flight is tolerated more easily than that for a flight to the east as, when sent to bed earlier (eastward flight), athletes find it hard to get to sleep until the normal time (biological time) - and then are expected to wake earlier than usual. As a result, some sleep deprivation occurs. In order to avoid disrupting the circadian rhythm unduly and allow the athlete to continue to train normally, an adjustment of the sleep-wake cycle by no more than 1-2 hours and for no more than 1-2 days is recommended.

During the flight
Generally, when onboard the idea is to change as much as possible the behaviour of the athlete to that appropriate to destination time in terms of activity, sleep and wakefulness, and eating meals. These strategies should be conveyed to the cabin crew, to avoid confusion and inappropriate times of waking the athlete, for example for meals. Further, there is a need to replenish the fluid loss due to the dry environment on the plane. Diuretics such as those containing caffeine or alcohol should be avoided during the flight, as they are diuretics and would accentuate dehydration. Due to the increase in incidence of deep vein thrombosis associated with inactivity in a cramped environment, performing isometric exercises, and leaving the seat periodically to walk around the plane, are advised.

After arrival
There has recently been some interest in the use of massage and deep breathing. Neither of these strategies has been shown to aid adjustment at the destination, though the value of massage to stimulate blood flow after travel is not to be discouraged. The two general approaches to readjustment are pharmacological and behavioural. The use of chronobiotics such as melatonin, which directly shifts the body clock or indirectly aids adjustment due to the hypnotic properties that aid getting to sleep at the new night-time, has received some attention in research on jet lag. There has been some concern with appropriate timing of melatonin to aid in readjustment after an easterly transition across 10 time zones. Further, when strict control of light-avoidance and exposure is not adhered to, the effectiveness of melatonin is reduced (1). The current position statement of the British Olympic Association advises athletes against using melatonin. Furthermore, in the UK, pure melatonin is available only when prescribed by a physician (8).
The behavioural strategy involves the appropriate use of the zeitgebers (time-givers) that aid entrainment – the light-dark and the sleep-wakefulness cycles, diet and meal-times, and activity and exercise. There is little scientific evidence to support the value of diet in promoting clock adjustment, the suggestion being to consume protein in the morning and carbohydrate at night-time, in order to promote arousal and sleep, respectively. In implementing adjustment strategies aimed at shifting the human circadian rhythm, an indirect marker for the body clock is used. This reference point is the body temperature minimum. Rectal temperature shows its peak value at ~18:00 hours and a minimum at 06:00 hours, and this 24-hour profile can be described well by a cosine curve (see Figure 1). Light is the strongest zeitgeber, and the effect of light depends upon the time of exposure, as described by a phase-response curve (2, 3, 5). Exposure to light during the 6 hours before the temperature minimum results in a delay, and in the 6 hours after the temperature minimum a phase advance. Exposure to bright light at other times results in no phase shift, and this is referred to as a “dead-zone”. If a phase-delaying strategy is used, in the case of a 10 time-zone transition to the east (UK to the east coast of Australia), this would mean exposure to light between 10:00-16:00 hours (local time) on day 1 and avoiding light between 16:00-22:00 hours. On day 2, as the body temperature minimum would have delayed by about one hour to 17:00 h by local time), the next day’s light exposure would be between 11:00-17:00 hours and avoidance between 17:00-23:00 hours, and so on for subsequent days. If a phase-advance strategy were used for the same journey, then light would be avoided before 16:00 hours for the 2-3 days in the new time-zone. It is generally found that readjustment tends to follow an exponential function, with greater adjustment occurring in the first few days (12).

Figure 2 shows the working example of a possible advantage of adjustment by a phase delay (14 hours) rather than advance after a time-zone transition of 10 hours. Peak performance generally occurs in the evening and the temperature minimum, associated with greater sleepiness and lowest performance, is found towards the end of sleep. The cosine curve has been transposed onto the local time in the new time-zone, with complete adjustment shown. Immediately after arrival, peak temperature and performance will be at about 04:00 hours and the minimum temperature value and worst performance at 16:00 hours. If a phase delay occurs, peak performance is delayed through the day such that it occurs later each day and sleepiness prevails through the evening. This adaptation means that there is some time of the day when high-quality training can take place during the process of adjustment. By contrast, an advance of the body clock by 10 hours moves the peaks of temperature and performance through the night-time in the new time–zone, and the temperature minimum and maximum sleepiness occur in the morning and afternoon. This timing indicates a theoretical advantage with adjustment by a delay rather than an advance after an eastward journey across 10 time zones. It also is more convenient with regard to light exposure for individuals arriving in the early morning in the new time-zone. There are, however, difficulties in translating theory to practice. In the field study before the Sydney Olympics, referred to above, adjustment was consistent with a delay for 35/85 individuals, with that of an advance of the body clock for 23/85 and for 27/85 it was unclear as to whether adjustment was by an advance or delay (7, 11). Such a separation of adjustment would have made it difficult to manage daily preparations in Australia after arrival. Therefore, with the additional consideration of departure and arrival times and keeping the teams as a whole entity, a ‘phase-advance’ strategy was chosen for all, involving light-avoidance in the morning, no morning training for 3-4 days, and a lie-in in bed for the first three days. This strategy worked well prior to the 2000 Summer Olympics.

Issues relating to athletes and jet lag coping strategies
Those athletes who were the more compliant tended to adjust faster than those who were resistant; the “poor adjusters” tended to be led by coaches and managers who were resistant to the advice, but rather stuck to “what they always did”, irrespective of the multiple time-zone transition. Training at a lower intensity and duration than normal for the first couple of days after arrival was advocated, to help reduce possible problems with injury. Exercise can take place outdoors at times advocated for light exposure, and tactics might be discussed indoors when light should be avoided. One of the problems at the destination is “anchor sleep” which refers to a short sleep period at the time the individual would normally have been asleep if living on home time. Such sleep contrives to “anchor” circadian rhythms to home time and this opposes adaptation to the new local time. For this reason, napping is not advocated for the first few days after arrival at the destination. On restarting normal training practices, the coach should monitor the athletes whilst they are not fully adjusted, and everybody’s expectations of performance should reflect this lack of full adjustment. When educating the athlete as to what jet lag is and what strategies should be adopted to minimise it, the encouragement of perseverance, compliance and a positive attitude helps to promote adjustment to the new time zone.

Conclusions: Looking forward to the Beijing 2008 summer Games
Essential planning and preparation include a comprehensive programme that starts prior to travel and includes coping strategies that apply both onboard and after arrival. The first question regarding UK and European athletes travelling to Beijing is ‘should they attempt to advance the body clock by 8 hours or delay it by 16 hours?’ Unlike the Sydney Games, where a delay of 14 hours was at least feasible, an 8-hour advance (for the Beijing Games) would be easier to achieve than a 16-h delay; behaviour to promote such an advance should be advocated. The behavioural approach of light exposure and avoidance, coupled with outdoor exercise and indoor discussions when appropriate, will be paramount in achieving this aim. The strategy can be implemented by raising awareness of the issues involved, and by providing clear guidelines on the actions required and the behaviour patterns to be avoided. The use of drugs such as hypnotics or melatonin is not advocated – although those athletes that already do use these means will not be advised against continuing to do so, but they should be monitored by their sports physician. Further, it is good practice to send key athletic support staff to the destination before the athletes’ arrival, to ensure they are prepared for the athletes and not getting over jet lag themselves when they have to be fully alert for work.
Key points:
  1. Jet lag is the result of rapid transition across multiple time-zones.
  2. Preparation prior to, during, and after arrival at destination can help reduce the symptoms of jet lag.
  3. Behavioural strategies such as light avoidance and exposure should be preferentially adopted rather than pharmacology.
  4. An educational programme providing feedback to athletes by oral presentations and in written form works well and provides informed advice as what to expect.
  5. Once the decision of the appropriate strategy has been made, all athletes in the team should be informed with the expectation that all follow the resultant programme.
  6. Some individuals take longer to adjust and report heightened symptoms and should be monitored until complete adjustment has occurred.

References
  1. Edwards BJ, Atkinson G, Reilly T, Waterhouse J, Godfrey R, Budgett R. 2000. Use of melatonin on recovery from jet-lag following an easterly flight across 10 time-zones. Ergonomics 43:1501-1513.
  2. Czeisler C, Kronauer R, Allan J, Duffy J, Jewett M, Brown E, Ronda J. 1989. Bright light induction of strong (type 0) resetting of the human circadian pacemaker. Science 244:1328-1333.
  3. Honma K, Honma S. 1988. A human phase response curve for bright light pulses. Jpn J Psychiatry Neurol 42:167-168.
  4. Klein KE, Wegmann HM. 1974. The resynchronisation of human circadian
    rhythms after transmeridian flights as a result of flight direction and mode of activity. In: Scheving LE, Halberg F, Pauly JE, editors. Chronobiology. Tokyo: Igku Shoin. p. 564-570.
  5. Minors D, Waterhouse JM, Wirz-Justice A. 1991. A human phase-response curve to light. Neurosci Lett 133:36-40.
  6. Reilly T, Atkinson G, Waterhouse J. 1997. Biological Rhythms and Exercise. Oxford: Oxford University press.
  7. Reilly T, Edwards BJ, Waterhouse J. 2003. Lang-haul travel and jet-lag:
    Behavioural and pharmacological approaches. Medicina Sportiva 7:E115-E122.
  8. Reilly T, Maughan R, Budgett R. 1998. Melatonin: A position statement of the British Olympic Association. Br J Sports Med 32:99-100.
  9. Waterhouse J, Reilly T, Atkinson G. 1997. Jet lag. Lancet 350: 1611-1616.
  10. . Waterhouse J, Edwards B, Nevill A, Atkinson G, Reilly T, Davies P, Godfrey R. 2000. Do subjective symptoms predict our perception of jet-lag? Ergonomics 43: 1514-1527.
  11. Waterhouse J, Edwards B, Nevill A, Atkinson G, Buckley P, Reilly T, Godfrey R, Ramsey R. 2002. Identifying some determinants of “jet lag” and its symptoms: a study of athletes and other travelers. Br J Sports Med 36:54-60.
  12. Wegmann H, Klein K. Conrad B, Esser P. 1983. A model for prediction of resynchronization after time-zone flights. Aviat Space Environ Med 54:524- 527.


List of tables and figures
Table 1. Mismatch between local time and body clock time (hour) after a flight from the UK to Beijing (8 time-zones to the east).
Figure 1. The cosine curve for rectal temperature over a 24-hour period, with an example of the strategy for light exposure and avoidance after a easterly transition of 10 time-zones.
Figure 2. Schematic representation of advancing 10 hours or adjustment by a 14-hour delay of the circadian rhythm of rectal temperature after an easterly flight across 10 time-zones. Shading indicates nighttime.
Table 1. Mismatch between local time and body clock time (hour) after a flight from the UK to Beijing (8 time-zones to the east).




Olympic Sport and the Ecological Ideal of a
Sustainable Development
Sigmund Loland
The Norwegian University for Sport and Physical Education
Norway

Abstract
The question discussed here is whether Olympic sport can be said to meet the ecological ideal of a sustainable development. The question can be understood in several ways. Some analyses focus on ecological costs in terms of the use of non-renewable natural resources, and pollution. A less common perspective deals with the nature of Olympic competition itself and its requirements on human resources. This latter perspective will be pursued here. The approach is analytic and casuistic. Firstly, the ideal of a sustainable development is defined and operationalized. Secondly, representative cases from Olympic sport are examined as to whether the requirements on human resources support this ideal or not. The ideal of a sustainable development is defined as a development that meets the needs of the present without compromising the ability of future generations to meet their own needs. A narrow interpretation of the Olympic sport and its motto citius, altius, fortius points towards continuous, quantitative growth of performance. This interpretation is seen to contradict the ideal of a sustainable development. A wide interpretation of Olympic sport opens for human complexity and diversity and qualitative measures of performance. Such an interpretation is seen to be ecologically sound. Olympic sport and its ideals are ambiguous. A narrow interpretation expresses an ecologically unsound quest for unlimited growth in limited systems. A wide interpretation opens for an ecologically sound exploration of human complexity and diversity in open systems. In conclusion, some critical comments are given on the possible role and consequences of the wide interpretation in future Olympic sport.
Key terms: Coubertin, performance, records, sustainability.

Introduction
In the so-called fundamental principles of the Olympic Movement, one key reference is the development of human kind through a blend of sport, culture, and education. In the mid-1990s, and due to an increasing awareness of global ecological challenges, the International Olympic Committee (IOC) included the environment as an additional dimension. The IOC’s Sport and Environment Commission emphasizes the responsibility for promoting sustainable development in particular ( For more information see http://olympic.org/UK/organisation/commissions/environment/games-uk.asp).

The operational outcome of this engagement is a set of requirements to be met by Olympic organizers in terms of plans for the environment and for waste and energy management. Although such measures are of value, they do not really matter much if the basic Olympic message is non-ecological in kind. The eco-philosopher Arne Næss (5) pointed towards the significance of what he calls deep ecological thinking in which the basic principles and values guiding and justifying our practices are critically examined. My perspective here will be a deep ecological one. My focus will be on what can be seen as the core of Olympic events, Olympic sports. My question will be whether ecological ideals are compatible with the values of Olympic sports, or whether there value conflicts here which are difficult to overcome.

Ecological ideals
Ecological ideals can be of many kinds. A basic distinction can be drawn between anthropocentric and non-anthropocentric perspectives. From the non-anthropocentric perspective, all life forms, or even landscapes, can be given moral status independent of their value to human beings. Non-anthropological theories challenge in fundamental ways conventional ideas about our relationship to nature, and they have radical implications for sport (2). It will lead too far to pursue this line of reasoning here. Anthropocentric theories on the other hand, in which the value of nature depends upon its role in the contribution to human well-being, are more conventional, and these are the perspectives to which IOC subscribes.
A core anthropocentric ideal, endorsed by the UN World Commission on Environment and Development (7) and by the IOC, is the ideal of a sustainable development. A sustainable development is defined as a development that meets the requirements of the present without compromising the possibilities of future generations to meet their own needs. Further elaboration points towards the dangers of specialized mono-cultures and to the significance of biological and cultural diversity and complexity. The ideal has been discussed in fields such biology, economy, technology, politics and culture. The question here is whether Olympic sports can be said to conform to the ideal.

Sustainable Development and Olympic Sports
According to the Olympic Charter, Coubertin’s ideology of Olympism is still the defining ideology of the Movement (http://www.olympic.org.uk/utilities/reports/level2_uk.asp?HEAD2=26&HEAD1=10). Coubertin’s extensive writings are not always clear and sometimes even contradictory. However, inspired by colleagues and friends, Coubertin succeeded in formulated a striking ‘slogan’ that has become the official Olympic motto: citius, altius, fortius (faster, higher and stronger). According to Coubertin, the setting of records has the same function in Olympic ideology as the law of gravity in Newtonian mechanics – it is ‘the eternal axiom’. The motto emphasizes the highly competitive performance orientation of elite sports, and it reflects the cult of objective, quantitative progress that characterizes the Western culture of modernity in which the Olympic Movement has found its form (1,6). From an ecological perspective, the continuous quest for improved performances and records has some deeply problematic implications.
Elsewhere I have discussed in more detail problems linked to high degree of specialization in sport performances (4). Here comes a brief sketch of the argument. A specialized performance is a performance based primarily on one or two basic bio-motor abilities (such as speed, strength, and endurance), and in which sport-specific technical and tactical skills play minor roles. Most record sports provide paradigmatic cases in this respect. What is at stake here is objective and standardized performance measurements in which the crucial parameters are those of speed, strength, or endurance. Take as an example a typical record sport, the 100-metre sprint race. Biologically, human capabilities for speed are limited. Although new records can be set again and again, every new record represents a further step in the utilization of this limited capability. The continuous quest for improved performance stimulates the development of more or less extreme performance-enhancing means and methods. Some of these, such as doping, have significant moral costs. As soon as a new record is set, the challenge for other runners, or for the next generation of runners, becomes greater. “Record sports” build on the impossible quest for unlimited growth in highly specialized limited systems. In this sense, they seem to represent non-sustainable systems and appear as biological and moral risk zones.
Other sports are defined by less specialized and more complex and diverse performance requirements. In ball games, for example, performances are built on technical and tactical skills, they are measured in non-exact entities such as points and goals, and they are always relative to an opposition (Figure 1). Although discussions of who is the best player or what is the best game ever are interesting and entertaining, there are no precise and agreed criteria upon which they can be settled. Games offer no possibility for record setting in the strict sense of the term. Every new contest is a new opportunity, and one great performance does not represent a utilization of resources that are not available to other players or new generations of players. Obviously, sports with more complex performance ideals constitute sustainable systems to a larger extent, and they are less vulnerable to excessive and morally problematic performance-enhancing means and methods. From the ecological perspective, they are sounder.

Concluding Comments
I have sketched an answer to the question of whether Olympic sports can be said to conform to the ideal of a sustainable development. The answer is both in the positive and the negative. I have argued that the Olympic ideal of highly specialized record sports performances is a non-sustainable one, and that games offer a more sustainable sport paradigm. The argument calls for some concluding comments
If the points above are valid, one should expect that specialized record sports will degenerate and vanish. Indeed, the degeneration scenario is possible. However, it is not the only one. Without being able to go into details at this point, I have pointed out elsewhere how record sports can be restructured into more complex, diverse and sustainable performance systems (3) and I believe that these are constructive alternatives worth considering here.
Another possibility is that the problem of non-sustainability is met by emerging, alternative sport paradigms such as those found in the increasingly popular board sports (such as surfing, skate boarding, snow boarding, and kite boarding). These activities build on non-quantifiable, creative performances with emphasis on individual expression and artistic values. As with games, they are less vulnerable to bio-medical performance-enhancing excesses than traditional record sports, and they might constitute a more sustainable Olympic sport paradigm in the time to come.

References
  1. Korsgaard, O. (1990) ‘Sport as a practice of religion: The record as ritual’. In: Carter, J. M. and Krüger, A.(eds) : Ritual and Record. Sport Records and Quantification of Pre-modern Societies. New York: Greenwood Press, pp. 115-122.
  2. Loland, S. (1995) ‘Outline of an ecosophy of sport’, Journal of the Philosophy of Sport XXIII: 70-90.
  3. Loland, S. (2001) ‘Record sports: An ecological critique and a reconstruction’. Journal of the Philosophy of Sport XXVIII: 127-139.
  4. Loland, S. (2004) ‘The vulnerability thesis and its consequences: A critique of specialization in Olympic sports’, in: Bale, J. and Krogh-Christensen, M. (eds): Post-Olympism. Questioning Sport in the Twenty-first Century. London: Berg, pp. 189-199.
  5. Nisbet, R. (1994) History of The Idea of Progress. London: Transaction.
  6. Næss, A. (1989) Ecology, Community and Life Style. Cambridge: Cambridge UP
  7. World Commission on Environment and Development (1987) Our Common Future. Oxford, UK: Oxford UP


Figure 1. The game of hurling engages technical and tactical skills, scoring is by goals (equal to 3 points) and points.
Characteristics:
  • all round and relative progress
  • non-specialization
  • technical and tactical complexity (games)
  • few limits to progress
  • sustainable




Contact:
Thomas Reilly
Research Institute for Sport and Exercise Sciences
Liverpool John Moores University
Henry Cotton Campus
15-21 Webster Street
Liverpool, L3 2ET
United Kingdom
T.P.Reilly@ljmu.ac.uk




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