Muscle performance

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Under muscle performance the amount of energy can be understood by the muscular work consumed per time interval or is released.

Terms

power

In physics, the power P is defined in simplified form as             :, i.e. as work W per unit of time t. The work detailed above is in turn performed by the force acting along a path:      

Service type

Two opposing service types can be distinguished in the sense of the service definition:

  • Maximum force type: Providing a service amount by minimizing the time interval (while maximizing the work to be done).
  • Endurance type: Providing the same amount of work by minimizing the work involved in a maximum time interval.

Motivation

The subjective willingness to perform is an expression of the fill level of the reservoirs of the key substances relevant for the respective type of service. It is at its lowest point at the beginning of the regeneration phase. The duration of regeneration depends on the use of measures that promote regeneration (eating habits, exercise, rest, ...). The regeneration phase ends with the supercompensation, i.e. H. in the period in which the material reservoirs are filled above the original level.

performance increase

The increase in performance occurs when the storage capacity of key substances has increased in relation to an initial value. In the course of this, the efficiency of the "processing organs" (heart, muscles, liver, ...) increases, whereby with the appropriate scaling there is "personal union".

Factors

Muscular performance depends on various factors:

  • on the organism's storage capacity of nutrients
  • on the supply status of the stores, in particular of fuels and minerals that are effective in catabolism
  • on the metabolic capacity of the metabolism (usually depending on the size of the organs responsible, e.g. lungs, skin (sweating), heart, intestines (wrinkles, villi), ...)
  • the quality and quantity of the substances supplied during the load.

Current state

  • Storage capacity
  • Supply status

PH value

Some cations are absorbed in compounds that have an alkaline effect in the metabolism (Ca 2+ , Mg 2+ , ...):

  • Amount of available mineral ions relevant for muscle function (in particular: Ca 2+ , Mg 2+ )
  • available buffer capacity (mainly stored in the blood buffer) to maintain the physiological pH optimum during muscle work
  • Breathing volume: responsible for the removal of acid-relevant CO 2

pH buffer:

  • pH reduction caused by CO 2 can only be buffered with non-bicarbonate buffers
  • on the other hand, the pH drop caused by lactate (and its formation) can be absorbed by the bicarbonate buffer. (???)

Mass transfer

Gas exchange:

  • the transport capacity for O 2 depends on the concentration and condition of hemoglobin (Hb)
  • the concentration of Hb depends u. a. the resupply of Fe 2+ from
  • the functioning of Hb depends on the oxidation state of Fe 2+ from
  • the binding (transport) of CO 2 to Hb competes with O 2 and increases with decreasing pH

CO 2 solution:

  • the chemical 'solubility' of CO 2 (as bicarbonate) decreases with the pH value.

Metabolism

Catabolism:

  • If the muscles are too active (transition aerobic → anaerobic), CO 2 accumulates as the end product of glycolysis
  • the complete breakdown of glucose or glycogen is inhibited, lactate is formed
  • the pH value also drops with lactate formation (lactic acid).

Observations

  • Low pH
    • As a result of low activity (blood flow) of the nutrient replenishment system (digestive tract): no regeneration of the body's own buffer systems, the pH value continues to decrease
    • Tissue (e.g. cartilage) soft, muscles resilient, large range of motion
    • Risk of injury is low as long as the pH is in the buffer range (i.e. bufferable cations are not exhausted)
  • high pH value (replenishment of cations, e.g. after eating, in the resting or regeneration phase)
    • Nutrient replenisher (digestive tract)
    • Buffer systems are regenerated
    • Tissue (muscle, cartilage) hard, stiff
    • Mobilization of negatively charged metabolites (mainly lactic acid: "slags") from the body cells (detoxification).

Connections

  • Muscle work - pH reduction - carbonate buffer - protonation - CO 2 outgassing - Ca 2+ release (excretion?)

Lowering the pH through metabolic work

  • CO 2 injection into the blood :

If the pH value is above 6.4, the reaction proceeds to the left:

CO 2 + 2H 2 O ↔ H 3 O + + HCO 3 -

A proton splits off and the pH value drops.

If CaCO 3 [solid] is available (bones, food) and the pH value falls below 6.4, it is dissolved. The pH value rises again as two protons and one CO 2 are absorbed. Calcium bicarbonate is formed:

CaCO 3 + 2H + + CO 2 ↔ Ca (HCO 3 ) 2

Calcium (here CaCO 3 from [Ca 2+ + CO 3 2− ]) acts as a buffer , in that CaCO 3 is dissolved when the pH is lowered through CO 2 in- gassing below pH 6.4 , and when the pH value is increased above 10 , 4 on the other hand CaCO 3 precipitates.

Meaning of calcium

From the above Reactions follows that the amount of available CaCO 3 (or calcium in other soluble form) is responsible for the amount of CO 2 that can be absorbed into the blood.

CO 2 + H 2 O + CaCO 3 ↔ Ca (HCO 3 ) 2 ↔ Ca 2+ + 2H + + 2CO 3 -

Since ~ 17 times the amount of Na + , like Ca 2+ (charge equivalents), is dissolved in the blood , Na + can be involved in the CO 2 regulation as follows :

2 NaHCO 3 + Ca 2+ → CaCO 3 + Na 2 CO 3 + 2H +

Description: CO 2 supply leads to the release of calcium (bones)

  • Hemoglobin - O 2 uptake - H + release

Muscular motivation

increase

  • pH reduction through muscle work (with sufficient nutrient supply)
    • Endurance exercise: Glucose or glycogen is burned to CO 2 , which lowers the metabolic pH value in the area of ​​the blood buffer
    • Maximum strength load: Glucose or glycogen is broken down into lactic acid and this is completely burned to CO 2 during the regeneration phase. Both degradation products have a pH-lowering effect, the complete degradation takes place late.
  • pH lowering through food intake
    • Short-term: Acids (vinegar, vitamin C (pKa: 4.2; 11.6), acidic juices, coffee (pH 4.9–5.2), smoking, etc.), acidic or acidified foods increase willingness to perform in the short term. The pH effect is, however, compensated for very quickly by metabolic buffer mechanisms.
    • long-term: bases or positively charged ions (cations, e.g. Ca 2+ , Mg 2+ ) stimulate the metabolism to produce endogenous acids. An increased urge to move can arise, the result is the formation of lactic acid, carbonic acid. This effect lasts as long as the movement itself.

Decrease

  • Increase in pH through ingestion of food (provided there is no deficiency in food components)
    • Short-term: Food with a high content of positively charged ions (minerals, electrolytes, e.g. calcium, magnesium). Equalization also takes place quickly, provided the metabolic buffers are “filled up” and the amount of cations absorbed does not exceed the capacity of the equalization mechanisms.
    • long-term: Acid foods are neutralized by the metabolism by consuming cations and thus deprived of their use in muscle work. At the same time, it signals to the body that there is an excess of acids and its own production is reduced.