Science-Backed 4-Day Workout Split That Maximizes Muscle Growth

Exercise scientists have identified the optimal 4-day training split for muscle hypertrophy, based on a meta-analysis of 87 studies on training frequency, volume, and muscle protein synthesis windows.

The Split

Day 1: Upper Push — Bench press, overhead press, lateral raises, tricep dips (4 exercises, 3-4 sets each)

Day 2: Lower — Squats, Romanian deadlifts, leg press, calf raises (4 exercises, 3-4 sets each)

Day 3: Rest

Day 4: Upper Pull — Pull-ups, barbell rows, face pulls, bicep curls (4 exercises, 3-4 sets each)

Day 5: Lower/Core — Deadlifts, lunges, leg curls, planks (4 exercises, 3-4 sets each)

Key Principle

Each muscle group is trained twice per week, which research shows produces 30% more growth than once-weekly training.