Physical fitness and stamina are crucial for the NDA exam's Physical Efficiency Test (PET). Here are some tips to help you improve your fitness level:

1. Set specific goals:
- Define your fitness goals and set a timeline to achieve them.
- Break your goals into smaller milestones to track your progress.

2. Create a workout plan:
- Consult a fitness expert or research online to create a workout plan tailored to your needs.
- Include cardiovascular exercises, strength training, and flexibility exercises in your routine.

3. Cardiovascular exercises:
- Engage in activities like running, jogging, swimming, cycling, or skipping to improve your cardiovascular endurance.
- Start with shorter durations and gradually increase the intensity and duration of your workouts.

4. Strength training:
- Incorporate exercises like push-ups, pull-ups, squats, lunges, and planks to build muscular strength and endurance.
- Use gym equipment or bodyweight exercises to target different muscle groups.

5. Flexibility exercises:
- Include stretching exercises like yoga or Pilates to improve your flexibility and prevent injuries.
- Perform static stretches after your workout or try dynamic stretches as a warm-up before exercising.

6. Interval training:
- Alternate between high-intensity exercises and active rest periods to improve your stamina and endurance.
- For example, sprint for 30 seconds followed by a 1-minute jog, and repeat for several rounds.

7. Proper nutrition:
- Maintain a balanced diet with adequate protein, carbohydrates, and healthy fats to fuel your workouts and aid in muscle recovery.
- Stay hydrated and avoid excessive consumption of processed foods and sugary drinks.

8. Consistency and rest:
- Stick to your workout routine consistently and allow your body enough time to rest and recover.
- Listen to your body and avoid overtraining to prevent injuries.

Conclusion:
By following a well-planned workout routine, incorporating cardiovascular exercises, strength training, flexibility exercises, interval training, and maintaining a proper diet, you can improve your physical fitness and stamina for the NDA exam's Physical Efficiency Test (PET). Remember to stay consistent, set realistic goals, and give your body enough time to rest and recover. Good luck with your preparations!