You have now spent ten or twenty or maybe thirty weeks building up mileage to prepare for your first 50K. You have finished your third 5 hour training run and the race you selected is three weeks away. What now? Well, the taper is almost like a reward for all the work. The taper runs will not be slow, easy runs. You will run at the same level of effort as you runs during the building stage, they will just be shorter.
I am going to assume you are following the 30 week plan I outlined in a previous post, The First Ultra - Training from a One Hour Run. The taper begins immediately following the final long run of your training. If your final run was 5 hours, run your usual mid week runs (Tuesday and Thursday) the same as always. If you have been running one hour each day, at an 8 minute per mile pace, then continue to run one hour at an 8 minute pace. The taper is on the weekend run.
On Saturday, two weeks before your race, simply go out and run about 3 to 3.5 hours instead of 5 hours. If I have been running 6 hill repeats during a 5 hour training run, I will cut back to 4 hill reps. then run a loop to complete a 3.5 hour run. What you are trying to do is keep running exactly as you have been running. Reduce the quantity not the Quality. Once again, your mid week runs should be the same distance and same pace as usual. (If your long runs were 4 hours instead of 5 hours then you first taper run should be about 2 or 2.5 hours.)
It is now Saturday , one week before your big race. Again, head out to your usual run location but this time run only 1.5 or 2 hours at your usual pace. You will feel like you have barely gotten warmed up before the run is over. Now, during the week I would only run one time, on Tuesday or Wednesday, and this time run at a slow pace. This is just a run to get the muscles warmed up and the blood flowing. Run for about 45 minutes.
Thursday night is critical. Eat a good dinner and get a good nights sleep. Go to bed early enough to get at least 8 hours sleep. More if possible. You may not sleep very well the night before a race. That really doesn't matter but you do need to sleep good two nights before the race.
Some people like to run on the Friday before a race. I do not, but an easy run will not hurt anything and it might help if you are nervous. If the race is local, just hang out and gather and sort gear. Try to think through the course and figure out how you are going to run the race. Look at maps and elevation profiles and estimate how long it will take to get from one aid station to the next so you will know how much water you should carry. Check the weather so you are prepared. If there is a chance of rain, consider whether you will need a rain jacket or not. Remember, in hot or warm weather a shower or storm my feel good. In even cool weather (50s) a storm can actually cause hypothermia. Just be prepared for what ever you might encounter.
Friday night, eat a light meal and eat early. Stay away from things that digest slowly like salads. Some people prefer to eat a bowl of soup or even drink a "Boost" or similar drink. I usually eat chicken and rice or pasta and I eat early, 4:30 or 5:00. I try to go to bed early enough to get at least 6 hours sleep.
Saturday morning I get up more than an hour before I have to leave to go to the race. Weekend after next is the Oak Mountain 50K, 10 miles from my house. The race starts at 7:30 AM and it will take me 20 minutes to get to the starting area. I will get up about 5:00, have a cup of coffee, eat a piece of toast or bowl of oatmeal and drink a Boost. I will leave the house by 6:15. I like to get to the race location early, otherwise I tend to get in a panic. Then I wait.
If you are traveling out of town to he race then there will be a few things you should do upon arrival. Most important is to locate the race site. Check out the area, find out where the start will be, look at the trails and run or walk a little on them. Drive around and try to see various sections of the course if that is possible. Know the route from your hotel to the starting area. Sometimes the start of an ultra is pretty difficult to locate. The Stump Jump in Chattanooga, TN, is a perfect example. I have run the race 4 times and I still print out a map and directions and usually make at least one wrong turn before reaching the start.
Don't forget breakfast if you are staying in a motel. You will probably need to leave before the restaurant opens and you might not want to eat at McDonald's before the race. I usually bring breakfast from home or stop at a store on Friday and buy what I want. If the motel doesn't have a microwave, I use the coffee maker to heat the water for my oatmeal. It works!