The Definitive 4-Day Workout Split | A Full Week of Upper/Lower Training That Builds Muscle

Four days a week is the golden frequency: the best balance of time, frequency, and recovery. An upper/lower split trains every muscle twice a week with 12-20 weekly sets.

Here's a ready-to-run week built around Monday, Tuesday, Thursday, and Friday.

Why upper/lower is the best 4-day split

Divide four days into upper and lower and you get two upper and two lower sessions: every muscle automatically lands at twice a week. With half the body per session, workouts stay at 60-75 minutes while leaving room for plenty of sets per muscle. A 3- or 4-way split on 4 days drops each muscle to once a week, so for muscle growth, upper/lower is the most rational choice.

Upper body days (Upper A / B)

Upper ASets x reps
Bench Press4x6-8
Bent-Over Row4x8-10
Overhead Press3x8-12
Lat Pulldown3x10-12
Lateral Raise3x12-15
Biceps Curl2x10-15
Upper BSets x reps
Incline Dumbbell Press4x8-10
Seated Row4x8-12
Chest Press or Dips3x10-12
Face Pull3x12-15
Triceps Pushdown3x10-15
Incline Curl2x10-15

Lower body days (Lower A / B)

Lower ASets x reps
Squat4x6-8
Romanian Deadlift3x8-10
Leg Press3x10-12
Leg Curl3x10-15
Calf Raise3x10-15
Lower BSets x reps
Deadlift or Hip Thrust4x5-8
Bulgarian Split Squat3x8-12
Leg Extension3x12-15
Leg Curl3x10-15
Calf Raise3x12-20

Laying out the week and managing recovery

The base layout: Monday Upper A, Tuesday Lower A, Thursday Upper B, Friday Lower B. Even on back-to-back days you're alternating upper and lower, so each muscle always gets at least two full days off. The weekend is complete rest, so recovery takes care of itself. If your weights start slipping late in the week, that's a deload signal: don't force more volume, back the load off for a while and let the fatigue drain. Run every set at RIR 1-3 and focus on one thing only: beating your last logged numbers.

FAQ

Should I start the week with upper or lower body?
Either works. That said, legs generate the most fatigue, so putting them early in the week keeps them from dragging down later sessions. It's also effective to schedule the muscle you most want to grow first, on your freshest day.
Will my arms and shoulders grow enough on 4 days?
Yes. The presses and rows on upper days give shoulders and arms substantial indirect work. Add the lateral raises and curls built into each session and your arms and shoulders get twice-weekly training with plenty of sets.
Can I train on days other than Mon/Tue/Thu/Fri?
Absolutely. As long as upper and lower alternate and the same muscle gets at least one full day between sessions, the layout is up to you. Tue/Wed/Fri/Sat works just as well.

Key takeaways

References

  1. Effects of Resistance Training Frequency on Muscle Hypertrophy: Systematic Review and Meta-analysis
  2. Dose-response Relationship Between Weekly Resistance Training Volume and Muscle Mass
  3. ACSM Position Stand: Progression Models in Resistance Training for Healthy Adults
  4. Low- vs High-load Resistance Training for Strength and Hypertrophy: Meta-analysis

That "just one more rep than last time" - captured every time.

Muscle growth only happens when you consistently beat your previous weights and reps (progressive overload). BTB Workout Log shows your last session's numbers the moment you pick an exercise, and automatically tallies your weekly sets by muscle group. No ads, fully offline, free to start - so you never lose track of where you left off.

Use BTB Workout Log for free