The short answer

The best split is the one that fits the days you can train every week, gives each muscle enough hard sets, and that you will still be running in three months. Choose by two things: how many days a week you can count on, and how long you have been lifting.

Days You are Split and article Program in Trenno
2 Beginner Full body: 2-day workout plan Beginner Full-Body, 2 days
3 Beginner, gym Full body: 3-day full-body plan, or the machine plan Beginner Full-Body Barbell, 3 days, or Machines
3 Beginner, for strength Full body in sets of five: beginner strength program Beginner Strength Barbell, 3 days
3 Beginner, dumbbells Full body: dumbbell workout plan Beginner Full-Body Dumbbells, 3 days
3 Beginner, no weights Full body: bodyweight workout plan Beginner Full-Body Bodyweight, 3 days
3 Intermediate Push pull legs Intermediate Push Pull Legs, 3 days
3 Intermediate on straps Full body: suspension trainer workout Suspension Full-Body, 3 days
4 Intermediate Upper/lower Intermediate Upper/Lower, 4 days, or with dumbbells
4 Advanced, for strength Upper/lower Advanced Upper/Lower Strength, 4 days
5 Intermediate Body-part split Body-Part Split, 5 days
6 Advanced Push pull legs Advanced Push Pull Legs, 6 days

A beginner here is someone in the first months of lifting. The American College of Sports Medicine calls a lifter intermediate after about six months of consistent training and advanced after years, and recommends 2 to 3 training days a week for novices, 3 to 4 for intermediate lifters and 4 to 5 for advanced ones. The table follows that.

Not every week fits a split. For those weeks there are shorter routines: a 30-minute full-body workout, a hotel gym workout for travel, and a resistance band workout or HIIT at home when there are no weights. Two more go on top of any plan: 20-minute core sessions and a 10-minute cooldown.

What each split does

The splits are ways of spreading the same work over the week. Counted from the rows of our programs:

Split Days Each muscle trained Hard sets a session A session
Full body 3 2 or 3 times a week 15 about 45 minutes
Upper/lower 4 twice a week 19 to 23 50 to 60 minutes
Push pull legs, 3 days 3 once a week 18 to 20 45 to 50 minutes
Push pull legs, 6 days 6 twice a week 18 to 20 45 to 50 minutes
Body-part split 5 once a week, with help from other days 15 to 20 35 to 50 minutes

Sessions last 35 to 60 minutes in every split; what changes is how often each muscle gets its turn and how many sets it collects over the week.

Where those sets land, for two muscle groups, counted by the body part each exercise is filed under in our exercise library:

Split Chest, sets a week Quadriceps, sets a week
Full body 6 9
Upper/lower 10 13
Push pull legs, 3 days 7 7
Push pull legs, 6 days 16 17
Body-part split 16 7

The body-part split gives the chest as much as the six-day plan, and the legs as little as the three-day one.

What matters more than the split

  • The weekly sets. A meta-analysis of 15 studies found a graded dose-response between the weekly sets for a muscle and its growth: more sets, more growth (Schoenfeld and colleagues, 2017). A split matters mostly through the sets it lets you do and recover from.
  • How often, second. An early meta-analysis found that, with the weekly work equal, training a muscle twice a week grew more than once (Schoenfeld and colleagues, 2016). A later one with 25 studies found no real difference between frequencies with the weekly work equal, and a modest advantage for higher frequencies when they also added work (Schoenfeld and colleagues, 2019). For strength the picture is the same: higher frequencies brought bigger gains, mostly because they added volume (Grgic and colleagues, 2018).
  • Showing up. A split that needs six days fails in a week with four. The minimum the WHO recommends for every adult is muscle strengthening on 2 or more days a week; every plan in the table meets it.

That is why the beginner rows are full body: they practice each movement often, which is what a beginner needs most. It is also why the six-day push pull legs split sits in the advanced row: it doubles the weekly sets, and only pays off when you can recover from them.

What to do after a missed day

  • Full body and upper/lower: do the missed session at the next one and keep the order. The week slides by a day; nothing is lost.
  • Push pull legs, 3 days, and the body-part split: each muscle has one day a week, so a missed day leaves it untrained for two weeks. Move the session to the next free day, and use the weekend as the buffer.
  • Never: two sessions in one day, or the missed day skipped to “get back on schedule”.

When to change your split

  • When your week changes. New job, new baby, more free evenings: pick the row that matches the days you can now count on.
  • When the program ends. The programs in the table run 12 weeks. At the end, run it again from heavier starting weights or take the next row: full body, then upper/lower or push pull legs, then the six-day version if you can recover from it.
  • When progress stops for two or three weeks on most lifts, and sleep, food and the log explain nothing. A split with more weekly sets is the usual answer.
  • Not because you are bored after two weeks. Progress is measured on the same lifts, week after week; a new split resets the comparison.

FAQ

Is a full-body workout better than a split?

For a beginner, yes, because it practices each movement several times a week. After that, with the weekly sets equal, research finds little difference between frequencies, so choose by your days.

Which split builds the most muscle?

The one that gives each muscle the most hard sets you can recover from, week after week. On the table, that is the six-day push pull legs split for an advanced lifter, and the upper/lower split for most people with four days.

Which split is best for strength?

A split that trains the main lifts heavy, often, and with long rests. Advanced Upper/Lower Strength gives each of the squat, the bench press, the overhead press and the deadlift a heavy day of 3 to 5 reps a week and a lighter day with another lift or a variation.

How many days a week should I train?

As many as you can keep for months. Two is the WHO minimum, three is plenty for a beginner, four to six suit intermediate and advanced lifters.

Can I change splits in the middle of a program?

You can, but you lose the comparison with your last weeks. Better to finish the 12 weeks and change at the end.

Sources

Every program in the table is in Trenno’s Explore, with its days, sets and rest times. Save one, and the plan for the week is set.