The best split for someone training four days a week

The goal of any split is to give each muscle enough hard work, often enough, across the week. Research on training frequency is fairly settled on one point: when you match the total weekly volume, training a muscle twice a week tends to build more muscle than training it once. Schoenfeld and colleagues reached exactly that conclusion in a widely cited meta-analysis of frequency studies.

An upper lower split hands you that twice-a-week frequency without any thought. Two upper days cover chest, back, shoulders, and arms twice each. Two lower days cover quads, hamstrings, glutes, and calves twice each. Every muscle gets its two exposures, the volume divides neatly across two sessions, and no single workout turns into a two-hour marathon.

Push pull legs (PPL) is an excellent split, but it is built around three session types: push, pull, and legs. Three does not divide evenly into four. So on a four-day week you are forced to either repeat one of the three days or run a rolling schedule that drifts across the calendar.

If you run push, pull, legs, and then a second push, your chest, shoulders, and triceps get trained twice while your back and legs get trained once. That is a lopsided week. A rolling PPL that ignores the calendar (push, pull, legs, push, pull, legs, spread over more than seven days) can work, but it makes your schedule unpredictable and is genuinely better suited to a six-day week, where each of the three days simply repeats and everything lands twice.

Run two upper days and two lower days that differ slightly, so you hit each muscle from more than one angle across the week. Lead every session with a big compound lift while you are fresh, then add isolation work to top up volume where the compounds leave gaps.

Across the week that lands each major muscle at roughly ten to fifteen hard sets, hit twice, from complementary angles. Your chest gets flat and incline pressing plus a fly. Your back gets both rows and vertical pulls. Quads and hamstrings each get dedicated work on both lower days. That balance is what fills a physique out instead of growing one or two showy muscles.

Four training days leaves three rest days to place, and where you put them matters more than people think. The aim is to avoid training the same region on back-to-back days when it is still sore, and to spread recovery across the week rather than clustering all your rest at the end.

1. The simple layout. Upper, lower, rest, upper, lower, then two days off. This is the most popular version because it separates each upper day from the next and each lower day from the next, with rest breaking up the week.
2. The spread-out layout. Upper, lower, rest, upper, rest, lower, rest. Handy if you recover slowly or your life makes consecutive days hard. It trades a little momentum for more recovery between sessions.
3. The condensed layout. Upper, lower, upper, lower, then three days off. Workable if the two upper days and two lower days differ enough, but it stacks fatigue and leaves a long gap before the week restarts. Use only if the calendar forces it.

Upper lower is the default, not the only option. A few situations point elsewhere.

• Chasing a lagging muscle. If your arms or shoulders trail, you can run three upper lower days and add a dedicated fourth day built around that weak point. This borrows from specialization programming without abandoning the twice-a-week base.
• Strength as the main goal. If your priority is a bigger squat, bench, and deadlift rather than size, an upper lower frame still works, but you will lean toward lower reps and heavier compounds with more rest, and treat isolation work as accessory.
• A pure full-body preference. Four full-body days can work for very lean, brief sessions, but they get repetitive and are usually better run as three days. For most people wanting four days, upper lower is the cleaner fit.