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Training of high-performance athletes is always like a "ride on a razor blade". A balance of necessary phases of overload and recovery will, in general and if all other conditions are all right, e. g. day form, environmental conditions, etc., lead to good competition results. A training/competition ≫ recovery imbalance, however, will result in performance incompetence and overtraining syndrome. [ABSTRACT FROM AUTHOR]

The sleep of humans and animals is influenced by environmental and inner organic circumstances like the sunlight and circadian rythms of hormones. Sleep by itself can be divided in phases of REM (Rapid Eye Movement)- and Non-REM sleep. Both sleep phases influence physical parameters as heartrate, blood pressure, muscle tension and they seem to be both essential for the organism. The change of sleep phases is centrally controled in the brain. But at present no single population of neurons and no single transmitter can be made responsible for the control of REM- and Non-REM-sleep. Research of the last three decades however could show that neurons in the gigantic cellular field (FTG) in the pons mainly control REM-Sleep. This part of the brain has mainly cholinoceptive receptors and cholinergic transmitters like carbachol can enforce REM-sleep and anticholinergic substances like atropin can suppress REM-sleep.Unlike cholinergic substances the influence of adrenergic and monoaminercig substances in sleep control could not be proven on a neuronal level. However since several years some authors postulate the influence of aminergic substances in sleep control. One of their arguments is the strong relation of respiratory neurons and sleep neurons in the same area of the brain and for respiratory neurons the parasympathic as well as the sympathic influence is proven. [ABSTRACT FROM AUTHOR]

From a physiological standpoint, exercise can impose a significant amount of stress on an organism. Muscular activity requires coordinated integration of many physiological and biochemical systems. Such integration is possible only if the body's various tissues and systems can communicate with each other. The nervous system is responsible for most of this communication through central command and peripheral adjustments. Regular exercise or training will result in better performance, however this ‘challenge of homeostasis' can lead to an disturbed balance between training and recovery. This stress is counteracted by several adaptive and regulation mechanisms. The physiological responses to any disturbance of the body's equilibrium and its ‘feed-forward'and ‘feed-back' from and to the brain is primarily the responsibility of the endocrine system . The endocrine and nervous system work in concert to initiate and control movement and all physiological processes it involves. When all facets of the central nervous and neuroendocrine system are performing in harmony, the ability to coordinate and regulate key physiological and metabolic functions, under the perturbations imposed by physical exercise, is quite remarkable. To date, relatively little attention has been placed on the role of the central nervous system in overtraining and fatigue during exercise and training. This chapter will focus on the possible involvement of the central nervous system in the onset of fatigue during exercise and the role of neurotransmitters and neuromodulators in possible mechanisms that underlie overtraining. [ABSTRACT FROM AUTHOR]

The physiological systems of the human body are placed under a great deal of stress during the process of exercise training. Within elite athletes this stress can be of enormous levels because of the volume and intensity of work they perform in their training regimes . When training stress is of an appropriate level then there is a positive adaptation in the human organism and typically physical performance improves. However, the converse can also be true—inappropriate levels of stress can result in negative, maladaptations and declines in physical performance. In the adaptive process to exercise training, it is well known that there is a need for rest and recovery from the stress of training. If this is not allowed, repetitive exposure to what would normally be an appropriate level of stress can become inappropriate in nature. When an inappropriate level of training stress is imposed upon the athlete there is a great likelihood of the athlete developing the "overtraining syndrome". Once this occurs, physical performance can decline so severely that the athlete's competitive season may be over. [ABSTRACT FROM AUTHOR]

Most of the research on endurance exercise has focussed on the physiological and metabolic demands during an event and on factors causing fatigueFatigue during and after prolonged submaximal running may have many origins. The conventional explanation for fatigue after running a marathon or ultra-marathon is that glycogen is depleted in the skeletal muscles, thus reducing their ability to produce force. This form of fatigue may occur only when the muscle glycogen concentrations fall below a critical level perhaps causing impaired sarcoplasmic reticulum function. Fatigue, particularly after prolonged exercise exceeding 4 hours, may also coincide with the development of hypoglycaemia. There is some evidence to suggest that this fatigue may be delayed if carbohydrate is ingested during the event. The fatigue associated with hypoglycaemia probably has its origins in the central nervous system (CNS). Another mechanism underlying CNS fatigue after prolonged exercise proposed by Newsholme et al. (1992)} is that as the duration of exercise increases, more plasma free-tryptophan crosses the blood brain barrier and is converted into serotonin, which increases the perception of fatigue.Fatigue after prolonged exercise, particularly in hot, humid environments may also be caused by factors affecting the CNS arising from sustained elevation of muscle and possibly brain temperature . Studies have also identified a type of neuromuscular fatigue which occurs during and after a marathon and which accounts for the decrement in running performance. The above discussion highlights some of the metabolic issues and aetiology of fatigue associated with prolonged submaximal exercise. [ABSTRACT FROM AUTHOR]

Whether they know it or not, anyone who has entered a weight training facility with the intention of getting bigger or stronger or improving physical performance has had to deal with the concept of an overload. This includes not only athletes, but also recreational lifters, those exercising for health reasons, and anyone going through a rehabilitation program. In order to alter the physiological system, it is necessary to expose the system to an unaccustomed stress. Only in this manner can the body respond by appropriately adapting to the stress. As with many stresses, the adaptation response is not immediate, and requires a period of regeneration. How long this regeneration period must be to permit complete recovery will depend on the training stress itself. In many ways, this training stress response is quite similar to the General Adaptation Syndrome as proposed by Hans Selye.33 The recovery time required following a training stress is directly related to the magnitude of the stress. In training terms, this stress is called an overload, or exposing the body to a stress beyond which it is accustomed.2 [ABSTRACT FROM AUTHOR]

Regeneration from the negative aspects of intense training is an important focus of the taper period prior to major competition. For nearly half a century, competitive swimmers have been attempting to optimise competitive performance by training close to the point of overtraining and then regenerating while the training load is tapered. Tapering is a regeneration technique during which the physiological and psychological stresses of daily training are gradually reduced prior to competition in order to maximise the difference between the positive and negative effects of training. [ABSTRACT FROM AUTHOR]

The modern training of athletes is based on the overload principle and negative feedback theory: the training stimulus must be strong enough to induce disturbance of homeostasis so that the body has to initiate reactions to adapt to the training stimulus. This means that overloading is a natural part of an athletes training process and provides stimuli for adaptation and supercompensation. Imbalance in the training load-recovery relationship is the primary factor contributing to overtraining syndrome. The reflection of overtraining syndrome on the ultrastructural level of skeletal muscle has revealed that the damaging effect depends on the muscle fiber type.Due to the destruction of myofibrils and atrophy of muscle fibers, exercise myopathy develops as a result of overtraining . The most sensitive to the long-lasting exhaustive endurance exercise are fast-twitch muscle fibers. The aim of the present study was to investigate the reflection of exercise myopathy on the ultrastructural level of fast-twitch muscle fibers. [ABSTRACT FROM AUTHOR]

Stressful high intensity training periods are necessary to obtain high performance in sports. However, the simple rule ‘the more — the better' does not apply in this context. A lot of studies clearly showed that systematic recovery periods in the training process are necessary to prevent an overtraining syndrome or staleness, and to obtain overreaching for further performance improvement. Sportmedical assessment of athletes' training states are used as valuable tools to determine the necessary amount of training and recovery in preparing an athlete for peak performance. In addition, authors using the Borg's Rating of Perceived Exhaustion (RPE,or the Profile of Mood States (POMS,clearly showed that changes in training load are reflected in subjective states and in the mood of athletes,In particular, studies dealing with the POMS have demonstrated that the typical ‘Iceberg-Profile' of the well-trained athlete changes during a phase of intensive training and deteriorates during overtraining.Morgan at al. reported mood changes in swimmers during the season. Early in the season, swimmers displayed the ‘Iceberg-Profile', a profile indicative of positive mental health that is associated with successful athletic performance. During overtraining, however, mood disturbances significantly increased and were accompanied by a profile reflecting diminished mental health. After training stimulus was significantly reduced following a taper, the swimmers again exhibited the original ‘Iceberg-Profile'. More recently, the existence of a dose-response relationship was demonstrated between training volume and mood disturbances Increases in training volume parallel corresponding elevations in mood disturbance (e.g., greater anger, depression, tension, fatigue, and less vigor and well-being). [ABSTRACT FROM AUTHOR]

Knee trauma and operations have a high incidence and economic relevance. They are among the most frequent injuries especially in sports. Recently, both diagnostic possibilities (such as MRT) and the surgical spectrum (meniscus suture, cartilage cell breeding) have increased. Internationally, an increase in minimal-invasive procedures can be observed, supported by improved surgical equipment. Rehabilitation has changed, too, in parallel to the technical and surgical developments—it has been characterized by early-functional rehabilitation concepts since the early 90s. In spite of advances in diagnostics, surgical procedures and physiotherapeutic rehabilitation, there are short and/or long-term changes in motoric function following trauma and surgery. The subject matter of Motor System has nothing in common with the subject matter of movement. "In this way, there is a clear distinction between the totality of all regulating processes and functions on the one hand, and the adverse outcomes of these processes, human movement, on the other hand." (Marhold 1995 from Beyer 1992, 425). > Deficient activation of the musculature is seen, especially the knee extensors, consecutive atrophy—especially of the M. vastus medialis—and coordinative changes may occur. For posttraumatic and postoperative changes—for both the deficits and the therapy- or training-related adaptations—the explanations are meager. It is therefore urgently necessary to provide explanations in order to establish adequate treatment. The following questions must be answered: 1.How are the receptors in the knee joint supplied and what structures may be mechanically damaged in interior knee trauma or following surgical procedures?2.What metabolic changes occur in conjunction with knee trauma or surgical procedures?3.Are there any nervous functions disrupted in interior knee trauma or surgical procedures?4.What changes can be measured in complex motor functions after knee injury and after surgical treatment?5.Is there a pattern in the measurable changes?6.What therapeutic consequences arise for rehabilitation? [ABSTRACT FROM AUTHOR]

The evaluation of the clinical state of an athlete, e.g. of current trainability and of the diagnosis of overload and overtraining, is already one of the most complicated tasks in athletic medicine. Training is not only repetitive physical exercises, but also regular regeneration as an integral part of a successful training program. As already shown in several experimental studies, clinical, metabolic and hormonal findings, including the psychologically-related monitoring of stress and recovery, seem to reflect the clinical state of athletes.Such parameters can be used to monitor training and regeneration in athletes. However, there remains some uncertainty concerning reliability of such parameters for monitoring training and regeneration of elite athletes during periods preparatory to major events like World Championships.This review deals with some of the aspects of these important practical and scientifical questions based on the experience of several preparatory training camps in rowing. Rowing has to be seen as strenuous middle time endurance stress of 5.5 to 8.0 minutes' duration, for which the athletes perform hughe training programs in which the monitoring of adaptation is essential to prevent long-term overtraining. [ABSTRACT FROM AUTHOR]

An essential task of hormones in metabolic control is to interference into cellular autoregulation and to ensure an extensive mobilization of resources of the body. Otherwise the actualization of potential capacities of the body is impossible. Accordingly, the exercise performance depends on influence of hormones on metabolic processes. Therefore, the magnitudes of hormonal responses in exercises, including competition performance, as well as their interrelations, allow us to understand the actual mobilization of various metabolic resources. However, in monitoring of training the significance of hormonal studies is not limited only by this approach. The determination of hormones can provide information on the adaptation to certain levels of exercise intensity and duration, as well as on disorders of adaptation, including exhaustion of the organism's adaptivity and overtraining phenomena. Hormonal responses can be used for assessment of the trainable effect of exercise session and for control of the recovery period. In order to get actually information and to avoid misunderstandings and wrong depiction, several cautions and limitations must be taken into the consideration. [ABSTRACT FROM AUTHOR]

Overtraining syndrome is a serious disorder, equivalent in severity to many orthopaedic injuries, and often sufficient to end a competitive season. Although various therapeutic approaches have been tried, overtraining syndrome is generally refractory to treatments other than an extended rest from heavy training and competition. Accordingly, prevention of overtraining syndrome is of critical importance. Although widely studied, the ultimate causes and pathophysiologic nature of overtraining syndrome are not fully understood .There is a general understanding of the factors likely to cause overtraining syndrome relative to the structure of the training program, with large increases in training load, training monotony, travel, frequent competition and social factors all thought to increase the liklihood of developing overtraining syndrome. Despite extensive study, the diagnosis of overtraining syndrome still remains a diagnosis by exclusion of other pathophysiologic abnormalities. Further, even with extensive laboratory facilities available, there are no universally agreed upon markers which signal the impending development of overtraining syndrome. Beyond this, the length of time involved in the analysis of complex hematological or hormone variables creates a feedback loop which is too long to be of significant practical value to coaches and athletes. Certainly, at the present time, there are no simple indicators of impending overtraining syndrome that are available to coaches and athletes. Given the nearly universal tendency for coaches and athletes to respond inappropriately to temporary training or competitive incompetence by doing more training, simple markers which might signal impending overtraining, or at least deteriorating overreaching, would be most useful. [ABSTRACT FROM AUTHOR]

The life of endurance athletes is about effort, effort during competition and especially effort during training. In preparation for an Olympic competition in the marathon, a race of about 2 hours, an elite runner may train 20 hours per week for nine months or more. In other sports such as cycling, swimming or Nordic skiing, the number of training hours may exceed this. In individuals willing to spend the time and effort to do the requisite training, remarkable endurance performances are possible. This ability to improve with training presents a seductive lure to do more and more training in quest of achieving a desired competitive result. However, it is clear that without the basic ability to perform at a good level with minimal training, no amount of training will "make a thoroughbred out of a plow horse". [ABSTRACT FROM AUTHOR]

Definition, types, symptoms, findings, underlying mechanisms, and frequency of overtraining and overtraining syndrome have been described in an introductory article to the present volume. During the past 10 years, our increasing knowledge in this field has also been discussed in different original and review articles well as presented at the 1996 Memphis Overtraining and Overreaching in Sports Conference and summarized in a book project. Aim of this present overview, which was presented during the 1997 Reisensburg Castle workshop, is an additional up-dating of our knowledge considering mechanisms underlying overtraining-related performance incompetence in affected athletes with respect to further results obtained in this field during the past 2 years. Particular emphasis has been given to the time-course of regeneration subsequent to overtraining as far as it is known at present. From an operational standpoint, the thesis was followed that findings such as impairment of neuromuscular function depressed β-adrenergic receptor density related depressed lipolysis, glycogenolysis, glycolysis, and heart rate response as well as depressed intrinsic sympathetic activity depressed turnover in contractile proteins depressed adrenocortical and pituitary-hypothalamic responsiveness in an advanced stage or iron deficiency can explain performance incompetence in overtrained athletes, whereas appropriate regeneration should be indicated by their normalization. [ABSTRACT FROM AUTHOR]