19 km at an easy aerobic effort on a hilly route

This week, we aim for 2 hours 20 minutes of easy running, including some hills, while keeping our effort controlled by heart rate. The focus remains on building the aerobic base There’s no need to rush the process—it will take as long as it takes for fitness to improve and for the runs to start feeling easier For now, all runs are easy, really easy. There is no speed work at this stage; the priority is developing a strong aerobic base