I started with 3 miles or so, now it's 4-5 miles or 30- 40 minutes.l ran an easy run today after a hard session of 4 miles to 5 miles and if l run 8 to 10 miles for my 1st run, then l just run 4 or 5 and it's just added miles. Like today l did a hard workout at 11am and came back a little while later with a 4 or so mile run. What do you do? And does doing a second run close together help?