The increase in performance generally is related to the achievement of adaptive changes in the organism. Adaptive changes can be achieved by repeated application of Exercise load. The way to achieve adaptive changes in the organism is a systematic repetition of Exercise load. Repeated loads refer to as adaptation stimulus. The principle of adaptive changes is the axis: homeostasis → adaptation stimulus (load) → adaptation.
If adaptation stimuli are applied properly, training can be expected to have accumulative effect. If motor activity is carried out in such a way that it evokes desirable current change of human functional activity, and consequently long-term, structural and psycho-social changes, it can be referred to as load.
Example : If I run every other night in the park without much planning and adherence to the principles of sports training, sooner or later pass the same track may be quicker, but also feeling more relaxed, which is a simplified functional change. Psychosocial changes in this case represent my daily effort and responsibility run out every night out.
Metabolic specificity of exercise and training is based on an understanding of the transfer of energy in biological systems. Efficient and productive training program can be designed through an understanding of the process of energy repletion for muscle work of various inensity and duration of load.
Adenosine triphosphate allows the transfer of energy from exergonic to endergonic reactions. Without an adequate supply of ATP, muscular activity and growth would not be possible.
Indicators of exercse load provide information on the condition of organism during training activity. They are sensitive to changes in the size of load. Among the indicators, there are:
The ability to resist external resistance with muscle contraction represents a basic principle of developing the complex of strength ability. Muscle contraction is conditioned by many factors. If there is no visible movements of body segments during muscle contraction, this is referred to as static strength (e.g. holding tim in squat when thighs are held horizontally to the ground). On the other hand, if muscle contraction causes a visible movement of body segments by stretching (excentric muscle contraction) or by shortening the muscle (concentric muscle contraction), it is referred to as dynamic strength (e.g. mutual movement of forearm and upper arm during benchpress exercise). The dynamic strength can further be divided into partial manifestations of dynamic strength:
Maximal strength is manifested by overcoming high or even limit external resistance at a slow speed with a specific muscle group usually in one repetition (e.g. in benchpress).
Explosive strength is manifested by overcoming low external resistance or weight of own body with maximal acceleration in single (acyclic) movement of participating segments (e.g. in throws, or take-offs).
Endurance sports are activities which are performed during longer time interval and which prevailingly use aerobic metabolism involvement. Aerobic metabolism prevails during physical exercise which is longer than than 2-3 minutes at a low, middle or submaximal intensity load. Exercies used are usually locomotions or repeated cyclic movements. Many scientific works proved that aerobic endurance may last for a longer time before fatique appears and that it can last even in the state of fatique. Also recovery rates are highly related to quality of endurance abilities and faster recovery allows the athlete to shorten rest intervals within and between training sessions and increase overall training load.
The most recognized model of endurance abilities physiology is the Cardiovascular/Anaerobic model, initially suggested by British physiologists A.V. Hill and associates in the mid-1920s. This model basically posits that a lack of oxygen in working muscles is what ultimately limits exercise performance. The cause of fatigue is primarily in cardiorespiratory system and utilization of oxygen. Most adherents to this model use the terms of VO2max, lactate threshold, and running economy when discussing aerobic or endurance training or physiology. Thanks to the new knowledge’s from this field of exercise physiology were made several new models from various points of view, e.g Neuromuscular fatigue model, Muscle trauma model, Biomechanical model, Thermoregulatory model, etc. Every of these models have wanted to supplement the initial model of Hill. The most complex revised physiological model proposed Nakes (2002) as a Central Governor Model. He draw from the original cardiovascular anaerobic model and four additional models that regulate short-time, maximal or long-time submaximal exercise. The basis of this idea is that fatigue is caused by CNS, which is not able to activate muscles to following activities or activities on a desired level. The brain protects the body by regulating power output during any form of exercise with the ultimate goal of maintaining homeostasis and protecting life. Muscle fibre power output is not regulated by factors in the muscle itself but in the brain based on continuous information from senses of the whole body. Fatigue is a relative process and as a consequence of it the exercise intensity is constantly changed during exercise as the brain either employs additional fibres to increase power output or to decrease fibre activation to adjust power output (energy) based on its calculations.
There are different manifestation of speed in training, e.g. the speed of a sprinter in a 100-meter run, reached javelin release speed, maximum speed of the starting run of the athlete in a long-distance jump, the speed of changing position of the middle player from the middle part of the net into side area, break-free with the ball in basketball etc. Sports performance is conditioned by performing a given movement with maximum speed possible. External manifestation of the resulting speed of both cyclic movement and single-speed movement are always related to as fast carrying out of the movement as possible along defined specific track through muscle contraction. The specificity of movement is given by specific skill in the sports discipline. Manifestations of speed in sports are always characteristic in their maximum intensity. Acyclic movement (throws, casts) can be performed against slight resistance (up to 20 % 1RM). Cyclic movement (sprint) is usually performed without resistance without any significant change is direction. During cyclic movement, a significant change in direction can occur accompanied with decrease and subsequent increase in speed and movement frequency (movement of player with the ball in handball). In this case, it is specific manifestation of speed which is called agility. As far as the duration of the performance of specific motor activity is concerned, it is speed up to 15 seconds (duration exceeding 15 seconds is speed endurance). An independent part of speed abilities is represented by the scope of reaction speed. Reaction speed is manifested by speed as a reaction to a given stimulus (e.g. reaction to start-up shot in 100-meter sprint) and it is understood as time lasting from stimulus to the start of motor activity.
Speed can generally be defined as an ability to reach high speed and frequency of cyclic, single-speed (acyclic) or combined movement through muscle contraction.
Coordination ability means an ability to quickly and purposefully perform difficult spatio-temporal movement structures. Within this context, coordination abilities are understood as an externally visible manifestation of the control and regulation processes of the motor activity of the central nervous system. The complex of coordination abilities consists of a group of basic coordination abilities.
Adaptive ability enables modifications of motor activity ob the basis of comparison or anticipation of new or changing conditions during performing motor activity.
Balance ability is understood as an ability to keep body or its parts in a relatively stable position.
Combinatory ability is understood as an ability to simultaneously put partial movements together into more complex movement structures.
Kinesthetic diferentiation ability means an ability to realize kinematic and dynamic features of movement.