Exercise physiology loss of integrity to the blood brain barrier. Hyperthermia also can lower cerebral blood flow, and raise brain temperature. Researchers once attributed fatigue to a build-up of lactic acid in muscles. However, this is no longer believed. Rather, lactate may stop muscle fatigue by keeping muscles fully responding to nerve signals. The available oxygen and energy supply, and disturbances of muscle ion homeostasis are the main factor determining exercise performance, at least during brief very intense exercise. Each muscle contraction involves an action potential that activates voltage sensors, and so releases Ca ions from the muscle fibre’s sarcoplasmic reticulum. The
Vacuum exercise Vacuum exercise The vacuum exercise is an exercise which involves contracting some internal abdominal muscles, primarily the transverse abdominal muscle, and not as much the diaphragm. Repetitions of the exercise may be used as a form of endurance training, and light strength training. There is difficulty building strength in the muscle, as it is not easy to apply resistance training to the deeper internal muscles. The reasons for performing this exercise vary. It has been done for aesthetic purposes in bodybuilding competitions (to suck the abdomen in, making it appear less bulgy). It can be done to enhance overall core