"Design a 4-week workout routine for a beginner who wants to improve their overall fitness and lose weight. Consider incorporating a mix of cardiovascular exercises, strength training, and flexibility exercises. Also, provide guidance on the number of sets, reps, and rest periods for each exercise in the routine."
Week 1:
Day 1:
- Cardiovascular exercise: 20 minutes of brisk walking or jogging
- Strength training: Bodyweight squats (3 sets of 12 reps)
- Flexibility exercise: 10 minutes of stretching

Day 2:
- Cardiovascular exercise: 30 minutes of cycling or using an elliptical machine
- Strength training: Push-ups (3 sets of 10 reps)
- Flexibility exercise: 10 minutes of yoga or Pilates

Day