lactate
when you exercise, the heart rate increases, (as does your breathing pace), so that more oxygen can be carried in the blood to your muscles. The more intense the exercise, the more your muscles have to work, so more oxygen is required and your heart rate will increase. The quicker you heart rate returns to normal, the better your fitness.
When a person is performing intense physical exercise and begins to feel fatigue and a burning pain in the muscles the response of the muscles is to synthesize more lactate or lactic acid.
During intense exercise, the majority of blood is allocated to the muscles to provide them with oxygen and nutrients needed for energy production.
its used in the body as an 'electrolyte' it helps the muscles from cramping during intense exercise.
Exercise increases the heart rate, because the blood has to supply additional oxygen to the muscles.
oxygen
During exercise our blood circulation speed increases. It effect in amino acid and a molecule ATP which causes muscles to increase strength.
Resistance exercise exerts particular muscles, and as a response, the muscles hypertrophy, causing them to grow larger and increase their work capacity.
Muscles take the stimulus of the exercise, rather offensively. Your muscles get stimulated by proper exercise and they becomes stronger and the size of muscles increases. The great scientists from developed world has done systemic study on this aspect. They probably have done permutations and combinations of exercises to get the best possible results.
Muscles can be strained in the abdomen from shoveling snow. Shoveling snow is an intense exercise that will strain most of your body muscles including the ones in the abdomen.
Before exercise, the arm muscles are in a relaxed state with limited blood flow. During exercise, the muscles contract and blood flow increases to provide oxygen and nutrients. After exercise, the muscles may feel fatigued and may experience micro-tears, which can lead to muscle growth and increased strength over time.
muscles get tired, reaction is slowed up and circulation of the blood increases