I'm three weeks away from my first marathon and should be starting my taper now, but I got sick recently and missed a pretty crucial week of training. I eased back in towards the end of this week and completed my longest long run today (and felt pretty good) but still missed one of two 20 milers. Should I treat this week as a normal training week (with one more 20 mile run) and then have a 2 week taper, or should I just proceed as planned?