Psychological  changes. Mood enhancement, influencing of the body scheme, self-perception and self-concept.

Immunity changes. Training is influencing psychological state, which is related to endorphin excretion (beta-endorphin) and other hormones (catecholamine, norepinephrine, etc.). Regular exercise is inducing secretion of anti-stress substances. It is presupposed that exercise stress mimics a state of analgesia, which is related to the effectiveness of beta-endorphin and other substances in the body, and consequently supports immuno-health.

Neurohumoral changes.  Exercising increases production of cortisol and this way blocks insulin release (Karlson Gerok, Gross, 1987) secretion of catecholamine and adrenal steroids. After exercising the production of somatotropin and anabolic corticoids is increased. Long term adaptation to the weight lifting stress is supported in the neurohumoral way. As explained earlier, first the motion control region is adapted after exercising (intramuscular and intramuscular coordination), then enzymatic changes within muscles occur together with biochemical changes and lastly you can find changes of the muscle cross section.

Tissue changes.

1. a) Bones: From the health point of view we can say weight lifting cannot be replaced during formation of the bone stock architecture by anything else. During any kind of load, the bone architecture adapts to the action of force.

        b) Mechanical: active zone determines our actual mechanical behavior and our adjustment in terms of adaptation. Variable mechanical stress causes the bones to be stronger, tougher, and firmer. People with movement deficiency may be in danger of weakening joints – potential fractures. The mechanics of functional adaptation of bones depends both on exertion intensity (inner tension of bones – that is the after-threshold activity is necessary in order to reach the stimulation of remodeling), and on speed of deformation change and number of cycles. Studies show that during bone stock remodeling (Petrtyl, Danes 2000), a close relationship exists between the mechanical load, main dominant tension, structure orientation and its elastic features. The structure of bone is made in a way to transfer relatively biggest and physiologically acceptable pressure and pull tension in order to minimize or exclude skid tension in main directions of the structure (Marik, 2000).

2. b) Muscles: Approximately 43% of the adult human’s weight is made of muscles. The muscle firmness varies between 50 to 90 N/cm2. If the muscle is not adequately trained (including rests) and if the proper nutrition is not secured, the muscle atrophy starts to occur and the building blocks of muscles (amino acids) are used as a source of energy.

In some cases, (according to the development / muscle involvement), it is possible to see repeated use of preferred muscle groups. The main indicator of this habit is not only muscle size, it can also be muscle density. Changes in muscle density after exercising have been tested using the computer tomography (CT) and found that muscle density of an elite athlete in comparison with non-training individual is only slightly higher. Measurements have also been done to a patient with an immobile knee joint, yet has excessive use in the compensatory mechanisms of walking hip flexor muscles (m. iliopsoas) and again it has been found out that the density of this particular muscle is almost the same as by an elite athlete.

References:

Tlapák Petr, 2014. Posilování kloubní kondice: centračně-stabilizační cvičení, Praha: ARSCI.