What causes your muscles to burn after a workout?

Answer 1

Lactic acid accumulation has been assumed to be the cause of muscle burn for many years. In the past few years, it has been discovered that lactic acid is not a by-product but is actually a source of fuel for muscles. So very little accumulates in the cells and greater lactic acid presence helps endurance, by providing needed fuel. Lactic acid will disappear within an hour of exercising, and is no longer thought to be responsible for muscle soreness that may appear 1-3 days after exercising.

Current thinking holds that calcium is the primary culprit for muscle soreness. Muscles contract through neuronal activation of calcium channels, which in turn cause the activation of contractile proteins. However, after continued activation, calcium channels become leaky. The muscles fatigue due to running out of the calcium supply to keep them contracting. As for the burn itself, it is not entirely clear. Some researchers hold that the same leaky calcium channels are also responsible for muscle burn, but it may just as well be other substrates within the muscle cells that are responsible.

Answer 2

When muscles are using energy faster than it can be produced by the normal aerobic route, there is also an emergency anaerobic energy procuction process, which yields lactic acid as a by-product. The lactic acid will eventually be carried away by the blood and re-processed by the liver, but it builds up temporarily in the muscles and causes the burning sensation that you have asked about.

Answer 3

Build up of lactic acid in the muscle tissue.

Lactic acid builds up when the muscles are being worked at such an intensity that the demand for oxygen eventually cannot be met, culminating in an excess of lactic acid. The end result is severe burning sensation of the muscles.

Answer 4

When muscles are worked vigorously they can not receive oxygen and energy from the body fast enough to sustain them. Because of this, they undergo lactic acid fermentation. Lactic acid fermentation provides the muscle cells with this missing energy, however the build up of this lactic acid causes muscles to burn.

Answer 5

Well your muscles don't burn, they ache usually. They do this because you work you muscles and they are not used to the training or whatever you're doing. But the ache is good and means that you are getting stronger.

Answer 6

You are exercising them, and almost pushing them past their tolerance. This is how they get stronger. The muscles are contracting and using energy sources such as Glucose and Glycerin.

Answer 7

because you are burning the fat that's in your body

Answer 8

The burning sensation is your muscles tearing, which makes you sore. After the muscles tear, your muscles will repair themselves and grow bigger.