1. Genetics and Breeding: The potential for a Pitbull to be big and muscular starts with genetics. If you're looking for a muscular dog, it's important to choose a reputable breeder who focuses on producing healthy and well-structured dogs.

2. Nutrition: Providing a balanced and appropriate diet is crucial for muscle development. High-quality dog food with a proper balance of protein, fats, and other nutrients is essential. Consult your veterinarian to determine the best diet plan for your dog's individual needs. 

3. Exercise: Regular exercise is key for building and maintaining muscle mass. Engage in activities like brisk walks, jogging, fetch, and even weight pulling (with proper dog training and equipment) to help your Pitbull develop strong muscles.

4. Strength Training: Incorporate strength training exercises, such as resistance activities like tug-of-war, flirt poles, and climbing, to help build muscle mass. However, be mindful not to overexert your dog, especially during the puppy stage when their joints are still developing.

5. Consistency: Consistent exercise and training routines are essential for muscle growth. Create a schedule that includes both physical activities and mental stimulation to keep your Pitbull engaged and motivated.

6. Positive Reinforcement Training: Use positive reinforcement techniques for training. Reward-based training methods, such as treats, praise, and play, can encourage your dog to learn commands and behaviors.

7. Socialization: Proper socialization from an early age is important for the overall well-being of your Pitbull. Expose them to different people, animals, and environments to help build their confidence and reduce the risk of behavioral issues.

8. Healthcare: Regular veterinary check-ups are crucial to monitor your dog's health and address any concerns promptly. Keep up with vaccinations, parasite prevention, and dental care to ensure your Pitbull is in optimal condition.

9. Rest and Recovery: Muscles need time to recover after exercise. Make sure your Pitbull gets adequate rest between workout sessions to prevent overexertion and injuries.

10. Love and Attention: Building a strong bond with your Pitbull through love, attention, and positive interactions contributes to their overall well-being. A happy and well-loved dog is more likely to thrive physically and emotionally.

Remember that each dog is unique, and genetics play a significant role in how muscular a Pitbull can become. Not all Pitbulls will naturally develop massive muscles, and it's important to prioritize their health, happiness, and well-being above aesthetics. Always consult with a veterinarian or professional dog trainer to ensure you're providing the best care for your furry friend.