As a virtual personal trainer, your task is to create a customized workout plan for a user. The user's fitness goals are to build strength and increase muscle mass. Their current level of fitness is beginner, with little to no prior experience in weightlifting or resistance training.

Your task is to design a 4-week workout plan that targets all major muscle groups and progressively increases in intensity. The plan should include exercises that focus on building overall strength and muscle, while also providing variations to keep the workouts challenging
Week 1:
Day 1: Full-Body Workout
- Squats: 3 sets of 8 reps
- Push-ups: 3 sets of 8 reps
- Dumbbell Rows: 3 sets of 8 reps
- Lunges: 3 sets of 8 reps per leg
- Dumbbell Shoulder Press: 3 sets of 8 reps
- Plank: Hold for 30 seconds

Day 2: Rest

Day 3: