EXECUTIVE SUMMARY

  1.  The Research Institute for Sport and Exercise Sciences has a range of research programmes that impinge on human enhancement technology. These are mainly focused on training, nutritional and behavioural manipulations.

  2.  Virtual reality environments may be employed to improve both physical and cognitive capabilities. Training programmes incorporating computer games may be adapted from clinical contexts for use by athletes utilising sophisticated mobile platforms. This system may be utilised alongside film-based training simulations to enhance decision-making capabilities in sports.

  3.  Athletes are continually in tune with the potential of ergogenic aids to help them achieve their goals. The adverse health effects of substances such as clenbuterol would render such drugs unethical, even if they were not illegal. Athletes are swayed in use of over-the-counter drugs by whether ingredients are included in the doping list. Such labile attitudes were evident after caffeine was removed from the list of prohibited substances. Use of creatine-loading is considered ethical by practitioners.

  4.  Evidence is presented that caffeine, theophylline, alkalinisers and creatine can positively alter physical performance capability. Caffeine can elicit cognitive improvements but no such benefits have been observed with taurine ingestion. Melatonin is currently being examined as a putative ergogenic aid when exercising in the heat but its benefits are questionable.

  5.  Athletes are commonly expected to compete in challenging environmental conditions. Environmental chambers are increasingly employed in the preparation of athletes for such environments. Tolerance to heat and altitude can be improved by "acclimation" in such artificial environments. Since such simulations lead to physiological adaptations over and above normal training, the ethical aspects of such practices are under scrutiny. Pre-cooling manoeuvres to effect acute improvements in the capacity to cope with heat stress seem ethically acceptable.

  6.  Pharmacological measures are increasingly advocated to help travellers cope with the disruption to their performance capability after crossing multiple time-zones. The phase-response curve of melatonin makes it difficult to administer this hormone as a phase-shifting method to accelerate adjustment to the new time zone. Light boxes that administer appropriate stimulation at the correct circadian times may be effective, but exposure to and avoidance of natural light are the preferred strategies.

INTRODUCTION

  The Research Institute for Sport and Exercise Sciences has a range of research programmes focussed on human performance from different disciplinary perspectives. These activities are dispersed across three main sub-areas, namely exercise performance, health, and chronobiology. The exercise performance sub-area is the one that is directly related to the elite end of the spectrum. Contributions to enhancement of human performance are generated from the other research groups, notably the knowledge base to maintain performance under thermal fatigue and environment stress. Further, research concerned with activity and health, and human ageing produces findings that have implications for high-level performance.

  The evidence presented is restricted to the potential for human enhancement technologies to improve sports performance. Technology is interpreted as the application of science: the technologies associated with our programmes in molecular biology and bioengineering are omitted from consideration since research outputs in these areas appear in the conventional scientific outlets.

A VIRTUAL REALITY TOOL FOR TRAINING AND TESTING CORE STABILITY

Introduction

  1.  In conjunction with the Royal Liverpool Children's NHS Trust, Alder Hey, the biomechanics research group has devised a balance training protocol which provides real time visual and somatosensory feedback in a multi-task environment. The primary expected benefits are the improvement of core and peripheral stability which lead to better balance, posture and movement in disorders such as cerebral palsy.

  2.  The potential for balance training was realised in the clinical context of cerebral palsy (CP) whose effects include loss of selective muscle control, muscle imbalance and deficient equilibrium reactions. The manifestation of these abnormalities around the low back and pelvis can be related to the concept of core stability which is defined as the ability of the lumbopelvic hip complex to resist buckling and to remain in equilibrium during external perturbations.

  3.  In spite of the primary damage to the central nervous system, motor function can be improved by controlled exercises and this gives rise to various training methods in CP aimed at improving core stability. Several methods exist for quantifying core stability including strength measurement and electromyography of lumbopelvic muscles. In our laboratory, a virtual reality game employed a multiple-task driven visual and somatosensory bio-feedback environment that was expected to serve both as an assessment and training tool for core stability in CP children. The engaging power of a virtual reality game can be used to measure and potentially improve core stability and general movement function.

  4.  The method entails standing on a CAREN movable platform (MOTEK, Amsterdam, Holland) facing a video screen, wearing a safety harness. The 3D position and orientation of the pelvis is calculated by a Vicon motion system in real time from reflective markers mounted on the two ASISs and the sacrum. Antero-posterior translation of the pelvis increases/decreases the forward speed, sideways translation drives the sideways speed and anterior/posterior pelvic tilt controls the ascent/descent speed of a virtual "magic carpet" in a real-time dynamic computer game involving a sea with islands, visualised in stereo.

  5.  In this early work, core stability was assessed by quantifying the movement patterns of the pelvis embedded in a multiple task setting, rather than by quantifying the underlying mechanism of muscle activity. The differences in movement strategies between the healthy control and the patient suggest that the method can be used to evaluate core stability. The complex virtual reality environment providing concurrent tasks is expected to train the patient for the functional demands of daily living. Future studies will examine the degree to which any improvement in core stability is carried over following training and whether it has a beneficial effect not only on posture but also on balance, co-ordination and other functional activities. It has likely implications beyond the clinical context to preparation of athletes for competitions.

  6.  Conclusion: this moveable platform, controlled by computer has great potential for enhancement of capabilities in a virtual reality environment. Conditions can be created whereby decision-making capabilities can be trained. At present there are only seven of these systems available worldwide and their application to sport and exercise science is in its infancy.

PERFORMANCE ANALYSIS

  7.  Much of our research programmes into improving human capabilities have been concerned with harmonising sports equipment and the individual's characteristics and capabilities within an ergonomics framework. There is also a considerable effort to optimise training practices and procedures with a view to optimising performance. The details of interventions are fed into counselling services we provide for practitioners and in their continuing professional development programmes. The most effective means of individual improvement are observed with performance analysis methods, when outcomes are presented as feedback to the performer.

Developing anticipation and decision-making skill: cognitive interventions

  8.  The ability to make decisions under pressure is fundamental to elite level sports performance. There is growing awareness that perceptual-cognitive skills such as anticipation, decision-making and situational awareness are essential pre-requisites for skilled performance. Elite performers develop sophisticated, task-specific knowledge structures as a result of extensive practice that enable them to deal with situations in a more effective and efficient manner than less elite counterparts. Elite performers search the visual scene in a selective manner, focusing their attention on relevant rather than irrelevant sources of information. Moreover, experts are more aware than novices of the likely events that may unfold in any given situation and are better at picking-up key contextual cues (eg, postural cues from an opponent) so as to facilitate situational awareness and anticipation of events. These skills are coupled with an extensive knowledge of available strategies and tactics and how these may be implemented in any given situation. It is also evident that successful performance in high level sport depends on an individual's ability to deal effectively with stress. Although researchers have shown that stress can lead to deterioration in perceptual, cognitive and motor performance, our evidence suggests that elite performers are less inclined to suffer the negative consequences associated with stress by developing effective emotional control strategies.

  9.  The prototypical experimental approach has been to capture the performance environment using either film or virtual reality simulations. Performers are typically asked to imagine themselves in the real-world situation and to make the correct decision quickly and accurately. A range of performance measures may be recorded during performance including response time and accuracy, heart rate, galvanic skin response, eye movements and concurrent verbal reports. These measures provide an indication of how skilled athletes differ from less skilled counterparts and provide a principled basis for designing systematic training programmes to enhance such skills. A combination of film- and virtual-reality based training simulations may be used coupled with instruction and feedback relating to successful performance strategies to enhance the underlying knowledge bases and provide an opportunity to experience the demands typically faced in the competitive situation under controlled laboratory conditions. The level of instruction may also be varied (eg, explicit instruction, guided-discovery learning, discovery learning) so as to create optimal conditions for learning and transfer. Our research team has already used these types of approaches to improve performance in many sports.

DRUGS AND NUTRITIONAL SUPPLEMENTS

  10.  The search for nutritional supplements to complement training is ingrained among practitioners. It is inevitable that athletes seek substances that have ergogenic properties, especially when faced with aggressive marketing that makes strong claims for the products concerned. Our experience with some of these drugs embraces substances that are on the banned list of IOC.

Clenbuterol

  11.  Anabolic adrenergic agonists selectively stimulate ß ²-adrenergic receptors ß²-AR) and induce protein accretion. These agents also stimulate lypolysis and because they lack androgenic side effects they are particularly attractive to female athletes. Clenbuterol is possibly the most potent and most frequently investigated ß ²-AR agonist. Administration of large doses (eg 1 mg.kg^-1 body weight) of this agent to livestock or laboratory animals induces significant growth of the heart and skeletal muscles. But, such administrations also induce significant myocyte death (apoptosis and necrosis) in striated muscles and increase the collagen content of the heart. Through meticulous investigation we have discovered a dose (10 ^-1g.kg^-1.d^-1) of clenbuterol that inducefs muscle growth but is not myotoxic, and this is similar to the maximum tolerable dose for humans. Infusion of this non-myotoxic dose of clenbuterol significantly increases (20%) the size and protein content of the skeletal muscles and this is associated with preferential hypertrophy of fast contracting myofibres. The peak power output of clenbuterol-treated muscles increases in parallel with muscle hypertrophy but their resistance to fatigue is diminished, and when compared to controls clenbuterol-treated animals have a lower maximum oxygen uptake. Moreover, despite negation of the overt myotoxic effects of ß ²-AR agonist administration, molecular markers of pathology were detected. Differential analysis of the cardiac proteome of saline- and clenbuterol-treated animals revealed significant modification of the blood protein, albumin. Mass spectrometric analysis identified this modification as acetylation of a lysine residue but it was not possible to determine which lysine residue was acetylated. Acetylation of the N-terminus of albumin is used as a biomarker indicative of heart failure, whereas, acetylation of other lysine residues within the protein is associated with an attenuated capacity of albumin to transport toxins such as bilirubin. These findings corroborate our previous studies and demonstrate the adverse effects of agents such as clenbuterol on performance and health.

Over-the-counter stimulants

  12.  The use of over-the-counter (OTC) stimulants by athletes was prohibited in sports competition until recently. In 2004 many OTC stimulants were removed from the World Anti-Doping Agency Prohibited List (WADA, 2004). Common OTC stimulants such as pseudoephedrine, phenylephrine, phenylpropanolamine and caffeine were placed on a monitoring programme, but their use by athletes was not restricted. The aim of the WADA Monitoring Program is to observe the use of such substances by athletes through the examination of in-competition drug tests carried out by WADA accredited laboratories. Current research at LJMU is attempting to examine the impact of these changes to the Prohibited List on the use of OTC stimulants. The current work is able to support the Monitoring Program laboratory data through assessing athletes' current use of these stimulants, reasons for use, knowledge and education regarding the Prohibited List and Monitoring Program and views on the changes made by WADA. Preliminary data suggest that 36.2% of respondents believe OTC stimulants to have performance enhancing properties and that pseudoephedrine is the most popular OTC stimulant used by athletes (23.2% of athletes having used it in the last 12 months). Whilst their ergogenic properties are equivocal, the removal of many OTC stimulants from the Prohibited List has led to a sharp rise in their use by athletes for performance enhancement.

Caffeine

  13.  As a common constituent of food and many OTC preparations, caffeine is particularly open to misuse in sport due to its apparent ergogenic properties and following its removal from the WADA Prohibited List. Indeed, the rise in the "Energy Drinks" market in recent years has seen a concomitant rise in the association of such manufacturers with sport. Current research at LJMU is examining caffeine consumption amongst sports competitors at all levels, specifically the use of caffeine in sport for performance enhancement. Preliminary results show that from a specific group of athletes (n = 83) 63% used caffeine for performance enhancement reasons and 17.5% had increased consumption post-2004. Coffee, energy drinks and caffeine tablets are the most prevalent of the caffeine products used.

  14.  Despite caffeine being so widely used by the general population, the evidence suggests a significant increase in its use in sport across all levels. Evidence of adverse health effects are limited. Together with the deregulation of other stimulants, the combined use of OTC stimulants for human enhancement purposes is extremely likely. Further research is warranted to assess the physiological effects of such combinations.

Caffeine and creatine

  15.  Caffeine and creatine are currently being used by elite football players, separately or in combination. Their use does not always coincide with scientifically established loading regimes. Significantly faster 15-m sprint times have been observed in our University 1st and 2nd team players during simulated football activity on 5 mg/kg caffeine one hour before exercise compared to placebo (double blind cross-over design). Time to fatigue after shuttle runs (20-m at 55% then 90% VO2max pace) was increased with caffeine. In a study of full time academy and reserve players from Wrexham FC, ball dribbling and 15-m sprint times were faster after simulated football activity when 5 mg/kg caffeine was consumed 60 minutes beforehand. Elite road runners have produced significantly faster times during a 10-mile treadmill run after ingesting 5 mg/kg caffeine one hour before exercise.

Creatine and Carbohydrate

  16.  Ingesting 10g creatine together with 200g carbohydrate immediately after 90 minutes of football-simulated activity resulted in improvements in a football skills task and time to fatigue 24 hours later compared with 200g of carbohydrate alone. Neither of these manipulations is thought to be unethical by practitioners (evidence from practitioner focus groups).

Alkalinisers

  17.  A dose of 0.5g/kg sodium citrate improved 5,000-m rowing performance significantly in six experienced male rowers. It was observed in a study of elite 400-800 runners that a dose of 0.3g/kg sodium citrate ingested three hours before five 30-s sprints on a non-motorised treadmill resulted in higher power output in the 3rd to 5th sprints. Whilst a 0.3g/kg dose of sodium citrate ingested three hours before an anaerobic capacity test enhanced time to fatigue, ie 20m shuttles at pace of 120%VO2max. Blood pH and bicarbonate were higher pre-test with citrate ingestion.

Other methylxanthines

  18.  Theophylline has got properties that suggest its potential ergogenic uses. Our observations on six subjects cycling to voluntary exhaustion indicate it increases arousal of the central nervous system. Its metabolic effects are not as great as caffeine and its alteration of physiological responses to exercise are relatively minor.

Taurine

  19.  Taurine is included in some commercial drinks, with claims that it is the main arousing ingredient in the fluid. We have conducted a study in which cognitive functions tests were employed concomitantly with exercise sustained for 90 minutes. There was no evidence that cognitive performance was any better under the taurine condition compared with a placebo.

Melatonin

  20.  This hormone is secreted by the pineal gland and it has both soporific and chronobiotic properties. It is marketed for resynchronising circadian rhythms, has purported health benefits due to its anti-oxidant properties and could help or hinder performance. We have had negative findings with melatonin on long-haul flights with athletes, due to the difficulties of timing its ingestion according to its phase response curve. Whist it has soporific effects that induce drowsiness and impair psychomotor performance short-term, there are no hangover effects after night-time ingestion. There are, however, other possible uses for melatonin such as when exercising in the heat. We have shown that there is an increase in blood flow to the skin during sub-maximal exercise in the heat. This response helps to reduce the rise in core body temperature and increases thermal comfort. We have not yet examined whether it allows the performer to tolerate a higher core temperature prior to hyperthermic fatigue and whether it compromises the safety of the athlete in such circumstances.

IMPROVING ENVIRONMENTAL TOLERANCE

  21.  Participation in exercise in unaccustomed environmental conditions can be impaired. Preparation for training and competition in such environments can improve performance and increase safety. This realisation has led to the use of environmental chambers in which physiological adaptation is achieved and tolerance to environmental stress is increased.

  22.  Currently the use of hypoxic tents and chambers for simulating altitude are under scrutiny by the World Anti-Doping Agency. Our observations on mountain marathoners have indicated subjective benefits of periodic exposure to normobaric hypoxia in an "altitude chamber" simulating 3,200 m, where the timetable was insufficient to alter the oxygen carrying capacity of the blood.

  23.  Acclimation in a heat chamber can produce positive effects that improve the capability to tolerate heat loads. Nine 50-minute exercise sessions spread over two weeks in about 30 deg.C and approx. 80% humidity have been effective in inducing adaptations comparable with natural acclimatisation.

  24.  An alternative means of improving heat tolerance is to increase heat storage capacity by pre-cooling the body before exercise commences. We have confirmed the ergogenic benefits of pre-cooling strategies, and the reduced risk of hyperthermic fatigue; such benefits may be reversed in competitive games in the heat when the body cools down during a half-time break. In such circumstances, a second cooling manoeuvre may be necessary. At present we are adapting this strategy to enhance the performance of fire-fighters.

Jet lag

  25.  The sensation of jet lag is not related closely to decreased motivation, to altered appetite, or to changed bowel habits; rather, it tracks the sensation of fatigue. In addition, in the morning it reflects problems with the sleep just taken; in the evening, problems expected with the forthcoming sleep. Jet lag is experienced by travellers crossing multiple time-zones and can adversely affect human performance. We have found it possible to accelerate adjustment to the new time zone by modifying behaviour and exposure to light rather than use pharmacological means. For athletes, a faster adjustment means quality training can be re-introduced and performance capability restored.

  26.  In the first days after a time-zone transition, important mental and physical tasks should be timed in the new time zone to take into account the unadjusted body clock. Poorer performance should be expected—not only due to the change in time zone but also due to the loss in sleep and effects of fatigue, and individuals should be prepared for them. This advice applies also to preparation for an event, where poor performances will have a negative impact upon individuals.

  27.  There is insufficient evidence to provide a rationale for the use or avoidance of sleep-inducing (such as benzodiazepines) or alertness-enhancing (such as modafinil) drugs; the problem is not their short-term effects but rather if there are carry-over effects and longer-term side effects (like dependency). Caffeine seems to be acceptable as a stimulant, if taken in moderation. Melatonin is widely used, but its lack of licence raises other problems, and trials of any long-term effects are still awaited. Melatonin might also promote adjustment of the body clock to the new time zone, but clear evidence on this is lacking.

  28.  A natural method for adjusting the body clock is by suitable timing of exposure to/avoidance of bright light (outdoors) in the new time zone. Physical activity can be coupled to this light exposure, not necessarily because exercise promotes adjustment of the body clock but rather because it gives a purpose to being outside in the bright light.

May 2005