“The long run is what puts the tiger in the cat.” - Bill Squires
There is no getting around the fact that long runs are crucial to a successful marathon training program.
1. Unless you are very experienced, long runs do not have to be fast. They are about building "resistance to fatigue", not speed.
2. You don't just start at 20 miles without following some sort of progressive build-up phase. Most would be marathoners are safe by adding 1-2 miles per week to your longest run, up to an absolute minimum of 15 miles. Everybody has an opinion on how far your long runs should be, and I am no exception. Depending on your speed, I recommend stopping most long runs at 2-2.5 hours, not to exceed 3, even if your projected time is 4 hours or slower. If you use distance as your measuring stick, I don’t recommend running beyond 20 miles in training. Based on personal experience, I think 18 miles is long enough, especially for beginners, provided you do enough of them. Running too far in training requires longer recovery, and trust me, if you can run 18 miles every weekend for a month, you can do 26.2 following a proper taper.
3. Surface. I believe that if you do most of your long runs off-road you recover faster. Ideally this would be on firm grass or trails that allow you to run at a respectable pace. I've found that many trails, especially those that are hilly, rocky, or at altitude, are run at a pace that is just too slow. If you can only cover 10 miles in 2 hours and hope to break 3 on race day, you might be better off back on the roads. The ideal situation would be to run on a smooth dirt or firm trail most of the time, then as your race draws closer mixing in a couple of your long runs back on the road.
4. How long? Unless you come from an ultra marathon background, I favor 18 miles as the long run upper limit for most runners because, as I mentioned earlier, recovery is so much faster than following a run 20 miles and beyond. Efficient, light weight runners are capable of going longer and may choose to do so because they can recover faster.
5. How many? Here is where my opinion varies from most marathon progression programs, that typically allow 2 weeks between your longest runs. I like to build up to 18 miles, and then maintain that distance for 4 consecutive weeks. Ideally, your first 18 miler comes 7 weeks out from your race and your last one 4 weeks out. Here is my 16 week progression for weekly long runs beginning with 8 miles:
Sample Progression of Long Runs
Week 16:....8 miles
Week 15:... 9 miles
Week 14:...10 miles
Week 13:...11 miles
Week 12:...12 miles
Week 11:...13 miles
Week 10:...14 miles
Week 9:....15 miles
Week 8:....16 miles
Week 7:....18 miles
Week 6:....18 miles
Week 5:....18 miles
Week 4:....18 miles
Week 3:....12-13 miles (race simulation)
Week 2:....12 miles
Week 1:....10 miles
I also like the 18 mile distance because the 9 minute per mile runners can still finish under the 3 hour limit (2 hr 42 min at 9 min pace).
Note the race simulation with 3 weeks remaining. Here is where you test your capability for maintaining marathon pace or faster for about half the distance. This won't prepare you for what's in store the last 6 miles, but can be a big confidence booster none the less. If you can schedule a half marathon race here, do it.
6. BE FLEXIBLE! There are many variations to long run build-ups. For example, Jeff Galloway recommends building up to distances of 26 miles and even longer, allowing a full 2 weeks in between. Hal Higdon uses 20 miles, as do most other programs, allowing 2 weeks in between. I like to stop at 18 so I can bounce back for another mid week quality workout before repeating the long one the following weekend.
7. The long run is more than just putting in the distance. Here is where you experiment with shoes; clothing, hydration and what form of calories work best for you (gels, liquid, or something else). Once you get beyond 15 miles, I would break out the shoes I plan to wear on race day for a test run or two, just to make sure nothing unexpected happens after 2 hours in them.
8. WEIGH YOURSELF BEFORE AND IMMEDIATELY AFTER ALL LONG RUNS! This is overlooked by the majority of marathoners, but avoiding dehydration is absolutely essential in preventing "the wall." You must try to drink enough to minimize large drops in body weight during long runs (4% or more). If you weigh 150, an acceptable loss would be 3 pounds (2%). Lose more than 6 pounds (4%) by 20 miles and you may have a long 6 miles ahead.
9. BUY A GPS OR MEASURE! Back in the day before GPSs, I used to estimate miles run based on time and how fast I thought I was running. More often than not I was off by 1 or maybe 2 miles on long runs, usually going shorter than I thought. Unless you measure or have a GPS, your 18 miler may actually be 16!
NOTE: Back when I was 43 years old, I ran 2hr 39 min at the 1997 Disney World Marathon placing 7th overall. My long runs were only 17 miles, but I had 3-4 weeks in a row where I did 2 of those every week- Sunday and Tuesday. Even though I had not run farther than 17 miles in a workout, I was very strong those last 6 miles!
(c) Dave Elger, 2009 All rights reserved