I'm alternating a/b workouts over 2 weeks of doing 15 reps. I gather I'm meant to up the weights each time - for 'progressive overload'. This makes sense - I'm upping weights 5kg each time (i.e. every 4 days, for exercises I alternate) but have been reaching failure on the 2nd set of chins/shoulder press. Do I keep upping the weights? So far, I've just stopped partway through the second set, then did the remaining reps after a short rest...
2nd question: the shoulder press is (aside from crunches) the only exercise I've been doing each workout. However, the weights only go up in 5kg increments - upping weight by 5kg every 2 days would quickly leave me knackered, as I'm only on 20kg now
Do I just up the weights every other workout, or would I be better doing an alt. exercise every other workout...
TIA
2nd question: the shoulder press is (aside from crunches) the only exercise I've been doing each workout. However, the weights only go up in 5kg increments - upping weight by 5kg every 2 days would quickly leave me knackered, as I'm only on 20kg now

TIA