I lost a month of all training due to a horrible virus. I've been back for about a week now, and have managed 3 slow plods and 2 cross training bootcamps. The boot camps were ok, but the runs are just horrible. I had done a 10km at a slow but pb 75mins at the start of August and was doing 5-8km 2-3 times per week. This morning I struggled through 3km in 26mins, and even had to stop for a short walk break twice. My legs feel like sandbags. Do I need to go back to week 7/8 of c25k to get myself going again, or is it just a case of keep going and it will eventually come back?