Myosin 'heads' in the thick filaments bind to actin; the filaments 'slide' relative to one another and thus the muscle contracts. During this process ATP is hydrolysed to ADP + Pj
In addition, the release of Ca2+ ions into the sarcoplasm leads to activation of glycogen breakdown, as shown in Fig. 8.8.
the interaction between myosin and actin, on the binding of Ca2+ to troponin, and on the enzyme phosphofructokinase, an important regulatory enzyme in glycolysis that is inhibited at low pH (see Box 8.4).
The ability to perform this type of exercise depends largely upon the bulk of the glycolytic, Type II fibres, and this bulk can be increased through training (discussed in Section 8.4.9 below). Certain interventions may aid performance. Recently there has been considerable interest in dietary supplementation with creatine in amounts of 5 g/day. This has been shown to improve anaerobic performance, by increasing the amount of phosphocreatine in the muscles. Another intervention that has shown some success in experimental situations is to ingest large amounts of sodium bicarbonate (NaHCO3), which acts as a buffer to minimise hydrogen ion accumulation and thus postpone fatigue.
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