True or False? Muscle Question..?

Here is the statement :





Muscle get tired as heavy object is lifted for a long period of time...


This is because the contraction of muscle cancels out the blood circulation in the muscle which means the muscle receive less blood causing it to fatigue...





True or False??


Explain...True or False? Muscle Question..?
False: The muscles are structured in such a way that they do not interfere greatly with blood vessel diameter (at least not enough to cause fatigue) when they contract. Although the causes of fatigue are still being studied, the body actually increases blood flow to active muscle to try to prevent fatigue. Fatigue possibly arises from the fact that highly active muscle's areobic respiration often exceeds the maximum transport of oxygen to the muscle, but not because the muscle inhibits blood flow in any way.True or False? Muscle Question..?
Don't take this as gospel, but my impression of what is going on:





True I believe, the blood removes toxins, lactic acid, that interfer with muscle contraction. If the work conducted by the muscle creates toxins faster than they can be removed then it causes the muscle to fatigue. When you work out your body becomes more effective at removing the toxins. Inmproving the effectiveness of your toxin remove takes more energy. Since the body will not waste energy on things it does not need you have to work out to induce a need on your body to improve toxin removal. This is why it takes training to improve endurance and why we aren't all a bunch of instant marathoners.
I thinks muscle gets tired because of lactic acid, and other metabolic by-products, not for lack of oxigen, if that were the case, the muscle would get hipoxic-isquemic and eventually die
False -- it gets tired because there is less oxygen and the muscle gets energy to move via anaerobic respiration. Which means there is a steady increase in lactic acid. That's just what i think, but im not 100%.