Researchers have long thought that fatigue is caused by a build-up of lactic acid in the muscles, but in the past decade, a number of teams have shown that this process does not cause fatigue (and may in fact prevent it).
Muscle-fibre cells contract when calcium ions are released inside them, under the control of ion channels called ryanodine receptors.
Now, a growing body of evidence suggests that fatigue is actually related to how these calcium ions are released and processed. It seems that the ryanodine receptors can behave erratically after excessive exercise or due to disease, allowing calcium ions to leak out inappropriately and leading to fatigue.
So Andrew Marks at Columbia University, New York, has developed a drug that can switch those receptors back to their stable state, making it harder for fatigue to set in.
His invention may make it possible for athletes, soldiers, or anyone else doing strenuous exercise, to stave off muscle fatigue for longer. Victims of diseases such as HIV, muscular dystrophy and cancer, in which fatigue is major side effect of the condition or its treatment, could also benefit, he says.
Read the full muscle-fatigue blocker patent application.
Justin Mullins, New Scientist consultant
