4-Day Workout Plan for Muscle Mass (Focus: Chest and Back) Day 1: Chest & Triceps Warm-Up: 5–10 min on a treadmill or rowing machine Dynamic stretches (arm circles, chest openers) Workout: Bench Press – 4 sets x 8–10 reps Incline Dumbbell Press – 3 sets x 10–12 reps Cable Flys – 3 sets x 12–15 reps Close-Grip Bench Press – 3 sets x 10–12 reps Tricep Dips – 3 sets x 12–15 reps Rope Pushdowns – 3 sets x 12–15 reps Cool-Down: Static stretches for chest and triceps (30 sec each) Day 2: Back & Biceps Warm-Up: 5 min rower or elliptical Light lat pulldowns (2 sets of 15 reps) Workout: Deadlifts – 4 sets x 6–8 reps Pull-Ups – 4 sets x max reps (use assistance if needed) Barbell Rows – 4 sets x 8–10 reps Lat Pulldown (wide grip) – 3 sets x 10–12 reps Barbell Curls – 3 sets x 10–12 reps Hammer Curls – 3 sets x 12–15 reps Cool-Down: Foam rolling for back Stretch lats and biceps Day 3: Rest or Active Recovery Light cardio (e.g., walking, cycling) for 20–30 min Mobility work or yoga Day 4: Legs & Shoulders Warm-Up: 5–10 min on a bike or stair climber Bodyweight squats and lunges (2 sets of 15 reps) Workout: Squats – 4 sets x 8–10 reps Romanian Deadlifts – 4 sets x 8–10 reps Leg Press – 3 sets x 10–12 reps Overhead Press – 4 sets x 8–10 reps Lateral Raises – 3 sets x 12–15 reps Face Pulls – 3 sets x 12–15 reps Cool-Down: Stretch hamstrings, quads, and shoulders Day 5: Chest & Back (Secondary Focus) Warm-Up: 5 min rowing machine Dynamic warm-up targeting upper body Workout: Incline Barbell Press – 4 sets x 8–10 reps Dumbbell Pullover – 3 sets x 10–12 reps Cable Crossover – 3 sets x 12–15 reps Single-Arm Dumbbell Row – 3 sets x 10–12 reps T-Bar Row – 3 sets x 8–10 reps Rear Delt Fly (machine or dumbbell) – 3 sets x 12–15 reps Cool-Down: