From Runner’s World:
A review of 50 studies on tapering published in the journal Medicine & Science in Sports & Exercise shows that levels of muscle glycogen, enzymes, antioxidants, and hormones--all depleted by high mileage--return to optimal ranges during a taper. The muscle damage that occurs during sustained training is also repaired. And if that isn't enough, immune function and muscle strength improve, as well, which reduces the odds you'll catch a cold or get injured just before the race. And get this: The average performance improvement by the subjects who tapered in these studies was 3 percent. That works out to 5 to 10 minutes in a marathon.
The review's main conclusion: "The primary aim of the taper should be to minimize accumulated fatigue, rather than to attain additional physiological adaptations or fitness gains." In other words, it's time to chill.
My last long run of 20 miles was 2 weeks ago today. That is right on schedule for almost all marathon taper plans. However, my mileage dropped down substantially do to some discomfort in my ITB. The week following that debilitating 20 mile run my mileage was cut back substantially. I did not run the Monday, Tuesday (I attempted to run intervals – I ran about a quarter of a mile), Wednesday or Thursday. I did some swimming, elliptical and cycling but no running for 4 days. And when I did get back on my feet it was slow – real slow – jogging like slow.
I did get back to the grind and churned out some miles. Some of the runs were a little bit faster but nothing near M (marathon) pace. I did not push the pace until a full 10 days later. At lunch, on Wednesday of last week I ran 6 miles at M pace and actually ended up 5 seconds per mile faster. I was back on schedule. So although not my normal taper procedure I did knock my mileage down. On Friday I ran another 4 miles at M pace. I missed out on almost all of my sharpening phase. I never had the satisfaction of getting all of my Yasso’s. I also missed some of my crucial hard tempo runs.
Sunday was obviously my last run of any substance. I ran 10 miles at M pace. Everything clicked off fine although it was tougher than I had hoped. I finished the run in the projected time and at about the projected heart rate. I just don’t like the thought of running another 16 miles at this pace.
The last week of training it is so important to stay on schedule. Don’t do anything stupid. The training is done. There is nothing physically to be gained.
In this last week the only thing that you can do is hurt yourself. It is time to be smart.