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
Liquid oxygen (supplement) the Federal Trade Commission fined the manufacturer for making false statements claiming health benefits resulting from the use of the product. The manufacturer had claimed that taking the supplement had beneficial effects on a wide variety of ailments, including angina, anaemia, and various forms of cancer, and that it also increased vigor and provided for a more positive state of mind. The company states that Vitamin O is "a special supplemented oxygen taken in liquid form and produced through electrical-activation with a saline solution from the ocean," and that the substance increases the amount of oxygen present in the blood.