Upper/Lower is the most-recommended split for intermediate lifters because it balances frequency, recovery, and time. Every muscle is trained twice a week, but you only need four gym sessions — leaving three days for rest, cardio, or sport.
The A/B wave structure keeps the heavy compound (squat, bench, deadlift, OHP) in front each day, then layers volume work behind it. Heavy day stays at RPE 8 on top sets; volume day pushes accessories to RPE 9. That combination drives both strength and hypertrophy without overlapping the same movement pattern two days in a row.
Run double progression on the working sets: stay in the rep range, hit every rep with form, then add the smallest plate increment next session. When you stall two sessions in a row on a main lift, MuscleBuddy drops volume and re-tests.
Default mesocycle is four hard weeks plus one deload. The deload is non-optional — it lets accumulated systemic fatigue (especially from deadlifts and heavy squats) dissipate before the next block starts.