Incorporating weights into decline crunches can elevate your core workout by adding resistance, intensifying muscle engagement, and enhancing overall strength. However, it's crucial to be cautious with the weight selection. Using weights that are too heavy can strain your lower back and increase the risk of injury. Start with a manageable weight, focus on proper form, and gradually increase resistance as your strength improves. Always listen to your body, and if you experience discomfort, reduce the weight or consult a fitness professional. Balancing challenge with safety is key to effective and injury-free workouts.