Compound movements train multiple joints and muscle groups together—squats, hinges, presses, rows, pull-ups. They let you load heavy and coordinate the body as a unit, so they are efficient for strength and total-body stimulus.
Isolation movements target one joint or muscle—curls, extensions, lateral raises. They are useful for addressing weak links, adding volume without excessive systemic fatigue, and hypertrophy where compounds alone leave gaps.
Most programmes lead with compounds when you are fresh, then add isolations for volume or rehab/prehab. If a compound always fails at the same weak point, both technique work and targeted isolation can help.
Try this: For each main compound in your week, list one isolation that supports it (e.g. squat + split squat or leg extension; bench + triceps work). Keep isolation volume moderate and recoverable.