Push/Pull/Legs (PPL) and Upper/Lower are two of the most popular ways to structure a training week. Both work — the right choice comes down to your schedule and how much volume you can recover from.
PPL splits training by movement pattern: pushing muscles (chest, shoulders, triceps) on one day, pulling muscles (back, biceps) on another, and legs on a third. Run twice through in a week, that's six training days — great for lifters who can train frequently and want higher weekly volume per muscle group.
Upper/Lower splits the body into two halves trained on alternating days, typically four days a week. Each session hits more muscle groups at once, which usually means slightly lower volume per muscle group per session but more built-in recovery between sessions.
If you can realistically train 5–6 days a week, PPL lets you spread volume out and recover well between sessions targeting the same muscles. If you're limited to 3–4 days, Upper/Lower gets you comparable weekly volume without needing as many gym visits.
When total weekly volume and effort are matched, research doesn't show a clear winner between the two splits. The best split is the one you can actually stick to consistently — adherence beats theoretical optimization almost every time.
Choose PPL if you want more training days and can recover well; choose Upper/Lower if your schedule is tighter but you still want to train hard. Either way, the fundamentals — progressive overload, adequate protein, and consistency — matter more than the split itself.