The 12-week online unassisted running plan is designed to help you progress from a half marathon level to a marathon. It is a self-guided program that provides a structured training schedule for 12 weeks. The plan includes a gradual increase in mileage, incorporating long runs, tempo runs, and speed workouts to improve endurance and speed. It also focuses on rest days and recovery to prevent injury and optimize performance. The plan is suitable for individuals who have experience running a half marathon and are looking to tackle the challenge of running a full marathon.