I’m mostly talking about front and side delts and in terms of fatigue and volume. Are the side delts and front delts isolated or do they accumulate fatigue?
For example, if I do 2 sets of lateral raises and 2 sets of shoulder press, is that 4 total sets of shoulders or is it simply just 2 sets of lateral raise and 2 sets of shoulder press?
You have primary strength movements (shoulder press, bench press, squats, dumbbell/barbell rows, etc)
Then u have accessories
to target specific parts, isolation.
you utilize part of ur medial delts to do shoulder presses, but the activation against the resistance is distributed to other positions and muscle groups throughout the movement; hence "compound movement"
Isolation exercises are to concentrate all of the activation to a very specific area you wish to develop, like side delts for example.
hypertrophy is the result of progressive overload (more resistance) and mechanical tension (activation, pump, negatives, everything that isn't momentum essentially)
Tldr; do single arm cable side laterals, raise the cable starting point to around hip height, get a D Handle (single arm attachment) and literally pull it to directly to the side, a straight line away from you. you'll prob need to do almost no weight on this bc its very hard, but if u concentrate on pulling it directly to the side, like ur holding a bag of grocercies all the way out w ur arm extended, you'll fully target ur side delt.