The type of weights you should NOT use if your goals is to build muscle mass is low intensity ( lighter weights). The correct answer is D.
I think the first one should be 107-125 because I found the average maximum hart rate for 47 year old male is 173-176bbp.
I think the second one is heart health zone. I found that this zone is when your hart rate is 50-60 percent of its maximum hart rate and the maximum hart rate for a 42 year old male is about 178.
the third one seems to be right
I think the fourth one should be glycogen depletion since it can't easily be replaced.
Yes it does because the larger the brain is the more room it has to do electricity in the brain
I was thinking but lost my train of thought sorry...