Lactic acid
Work a good honest day's hard physical labour.
When muscles work hard, they produce lactic acid as a byproduct. The accumulation of lactic acid can lower the pH level in muscles, leading to fatigue. This can interfere with muscle contractions and reduce their ability to generate force, causing muscle fatigue.
when you work out
When their muscles work
it is from a lack of water in your body Edited: Because lack of ATP.
Massage relieves tension in the body's muscles, removing lactic acids which can age and become toxins, causing temporary nerve damage if not relieved. People who work their muscles constantly often say they have very stressed muscles, this is because the pain receptors are picking up on the lactic acid, and tension builds inside of them.
No, frequency is about how often.
we are using our muscles
When muscles work without enough oxygen, they produce a byproduct called lactic acid.
They should use more oxygen your muscles burn either sugar or fat, it doesnt need oxygen to burn sugar, but the by product of burning sigar is lactic acid or pruvic acid, anyway it makes your muscles ache. if you are exercising and breathing hard, then you are burning sugars. to burn fat your muscles need oxygen. The harder you work the more ogygen is required.
Lactic acid builds up after you work out hard. Your muscles are exhausted and need to repair themselves. Check out the related link to find out tips on how to reduce muscle soreness after prolonged use.
Muscle cells need more oxygen when they are working hard. When you are working very hard and you begin to respire anaerobically (when the muscles don't get enough oxygen so work without it) your muscles produce a bi product of lactic acid, which is what makes them ache.Your muscles need oxygen to break down this acid into water and carbon dioxide, and this is called an oxygen debt.That is why you keep breathing heavily after you have stopped doing the activity.