A) A group of people working toward a shared goal
The answer is : increased resistance need to be added to the muscles.
Muscle conditioning refer to muscle strength and endurance. In order to improve it, you need to put your muscle in a harsher condition in a harsher condition than it used to be, so your muscle could adjust to it. That's why you should keep increasing the resistance
Answer:
The heart is made of three layers of tissue. Endocardium, the thin inner lining of the heart chambers that also forms the surface of the valves. Myocardium, the thick middle layer of muscle that allows your heart chambers to contract and relax to pump blood to your body.
Explanation:
Lactic acid build-up was the cause of muscle fatigue.