I bought a pull up bar and have been doing chin ups every time i walk by it. Put it in a good place in my hosue so im doing at least 100 a day. Lately i dont feel anything in my biceps, only my tricpes are burning and a little sore at the end of the day. What has changed? I usually do 10-15 every time i walk under it/ by it. I still feel exhausted at the end of each one like i cant do any more unless i kick up, so what gives? why have my biceps stopped caring? I dont think my form has changed at all.