Question

Age: 20
Male
57.1 kg
Goal to gain weight and strength
medical issues: none

I was in the gym doing barbell curls for 15kg 10 reps, on the start of the 3rd set (final) My left arm was no able to generate any strength at all. There was/is no pain now a day later and normal functions are easy. I went to try a dumbbell curl with the left just 5kg and it was immensly difficult and i could barely lift it. What could I have done?
Again, no pain no signs that i was over working, i did the 10 reps without fail, no real struggle, good form. But all of a sudden i go to do the next set and no force can be generated.

Answered by Roman Footnick

A. Nervous system problem (i.e. Neuropathy, stroke, etc.):   Go see a physician or medical professional (acupuncturist, chiropractor, etc.)

B. Muscular problem (i.e. myopathy): Go see a physician or medical professional (acupuncturist, chiropractor, etc.)