Specificity is the answer. You are targeting a certain muscle in your body to improve it for an upcoming sport or activity like running a marathon or entering a Mr.Olympian body-building competition.
Because vaccines have healthy viruses that try to get your body to be immune to the diseases so when you are already sick your body won't respond to the vaccine because it's just more viruses
The three main categories are health, disease and safety.
The red blood cells have proteins, hemoglobin and myoglobin, that are responsible for the storage of oxygen from the lungs and transporting it through the body. When the hemoglobin and myoglobin are low, it is because the iron levels are low. When this occurs, the blood, which carries the oxygen, reduces the ability to process its work. When this occurs, anemia, a condition that may cause chest pain, tiredness, and headaches.
Answer:
There are five principles of fitness out of which two are overload principle and rest and recovery principle. Overload principle is one of the most important principle which tell that to gain and improve the fitness one should do the hard work.
Slowly and gradually the intensity and time of exercise are increased so that our body can adapt to the hard work. Overload principle plays an important role in improving the skills and improving performance during exercise and sports.
Rest and recovery principle is important to relax the body and release the stress that happens due to intense training like in case of weight lifting one day rest should be taken to repair and rebuild the muscles. This allows the body to encounter the fatigue and improve performance.