Answer:
Yes!
Explanation:
This is because you can not see anything so therefore you can't do a lot of stuff. But you can use a light, though that will hurt your eyes if you do it every night. :) Hope this helped! :P
B . It is completely normal . However if you are experiencing extreme pain stop and consult your doctor . Also if you are prone to any kind heart disease let someone know where you are when exercising or better yet let them be at your side at all times .