35 year old male training for first marathon (London 26th April). I ran my first half marathon in March 2019 and surprised myself with a 1:30:52 time since I’d mostly run a couple of days a week with my dogs and didn’t follow any training plan. I am now 11 weeks in to the Hansons Marathon plan. It’s my first marathon and based on the half I would very much like to achieve the time the many extrapolation tools say which is around 3:10. The training is going well and the hardest part has been sticking to the slower paces. I don’t really trust my GPS so I try to run a little faster and/or a little further just in case and if it was accurate the whole time then it’s a bonus, provided I don’t overdo it of course. To get to the point, I will complete the 18 week plan around 15th March, 6 weeks before the actual marathon, so I am hoping for some advice on what to do with the extra time. Due to the longest run being 16 miles I am tempted, like many others, to do a 20+.