🎓 📝 LAB REPORT-365 📝 🎓
#7 What is Muscle Fatigue and how does it happen?
Fatigue is basically what you feel during exercise (the burn) or the inability to continue with an exercise. There are a number of reasons that can cause the sensation of fatigue in the body when training. These reasons include Fuel, Hydrogen Ions, and calcium in muscle cell action.
To move, you need ATP (Adenosine Triphosphate). This is energy. Everything you eat is converted to ATP when you move (this is grossly oversimplified). For intense activity, the body relies on an Anaerobic Pathway but there is a limited store of energy (ATP/CP pathway lasts about 10 seconds and the Anaerobic Lactate Pathway lasts about 2 mins). The Aerobic Pathway produces a lot of ATP through the breakdown of glucose and glycogen, which requires oxygen, carried by the blood to support the entire process. The Cardiovascular system has a limited ability to deliver blood and oxygen to the working muscles.
When glucose or glycogen is broken down, it produces lactate and hydrogen ions (H+). If there isn’t enough oxygen is available to working muscles then hydrogen ion concentrations increase and the blood will become acidic. When this happens, it begins to block the nerve signals from the brain to muscles. This make s the muscles feel heavy and movements begin to slow down. This occurs to allow more oxygen to get to the working muscles.
The function of calcium n muscles it to help control contractions. Long bouts of intense exercise causes fatigue, which in turn may be caused tiny leaks of calcium in muscle cells. This calcium leak weakens muscle contraction and can stimulate an enzyme that “attack” muscle fibres, which results in muscle, fatigue. These leaks stop after a few days.
What do you do with this information?
Eat, sleep, train, repeat.
EDWARDS, R. H. (1981) Human muscle function and fatigue. Human muscle fatigue: physiological mechanisms, p. 1-18