@robg You might be under eating...
I have been working out for years, and whenever i workout and don't get all my macros in, the next day i am very tired.
@lizlugo51 Regardless of how your split is, you "need" to add an "arms day"... Away from chest and back days so the muscles are fresh when you train them.
Choose 4 biceps and 4 triceps exercises & super set them with 1.5 min of rest between each super set.
Range 8-12 reps, 4 será each exercise...