A build-up of lactic acid is often wrongly blamed for making our muscles feel heavy and tired after an intense workout. Scientists have now proved that it is actually a friend, not a foe, that improves the health of the brain when we exercise.
A study even suggests that we could give our brains a similar boost by injecting the substance created by our muscles without having to exercise at all.
During exercise the body breaks down glucose to release energy. During a more gentle workout, oxygen from breathing is used as the main fuel, helping to break down the glucose in a process known as aerobic glycolysis.
During more intense exercise, the body can no longer get enough oxygen to keep up with demand from the muscles. At this point, the body has to start breaking down glucose without oxygen, in a process known as anaerobic glycolysis. One by-product from this process is called lactate.
It is common to hear amateur athletes and even sports commentators blame a “build-up of lactic acid” for muscle fatigue, but this is incorrect in two ways.
