Say I've run 100mpw before and have been in 14:00 5k shape (two years ago). I'm now running about 50mpw after about six months of very light exercise. I built up to this mileage over the course of one month. I ran a 1600m time trial recently in 4:38, which was kind of demoralizing since I've finished 10ks faster than that. I'm hoping to be in sub ~4:20 indoor mile shape in another 4 weeks. Do you think that's doable? My PR is 3:51 for 1500m outdoors. I'm focusing mainly on mileage, losing about 5lbs, and getting in decent threshold runs and strides. Thoughts?