Workout for the day-Running in Oslo

Two weeks of training after Easter is accomplished. I've been running half the amount in length as I did in the first three months of the year. Clearly I've been rearranging my priorities. Well, then. A long run to day, easy, on the road. My aim is to keep the speed on marathon-level. For now this is 6 min/km(9,6 min/mile). In doing this I keep my heart rate between 150-160. I've finished three marathons by doing this.I felt strong most of the time, but I felt the fatigue when approaching the ascend from the harbour in Oslo towards the suburb Helsfyr. I did some test on a new energydrink called Yt. It consists of different kinds of fruit juice-lemon and raspberry. It served me well during the exercise. I had 0,3 l of it during the length of the exercise of 2h 42 m. Most important to me during an endurance-workout is to consentrate on executing as good running technique as possible while maintaining speed and heart rate within limits.I have to keep on increasing the lengths of my long run. This one ended on 28 km(17,5 miles). Additionally I have to move my workouts to the trails. I'm starting my running on gravel roads and gradually moving out in the terrain. Anyhow, my long runs will be on roads paved with asphalt the next two weeks. By the end of May all my long runs will be on trail in the terrain.Regarding length of the workout I have to work my way up to 5-6 hours. I should be able then to cover about a marathon in an endurance-workout.Up to know my body is responding well to the training. I hope it stays that way.