Long runs are the cornerstone of training for distance runners. Among the many beneficial adaptations to long runs are increased glycogen storage (your body's carbohydrate stores) and increased fat metabolism. Following are ways to approach long runs to maximize the training stimulus.
How hard should your long runs be?
The appropriate pace for a specific long run depends on the purpose of that run within your training program, the number of weeks until your goal race, and so forth. The context of that run determines the optimal intensity of the workout.
1. Building race-specific endurance: Most long runs are for building endurance, either to prepare for a marathon or to improve your aerobic base for shorter events. When your legs are reasonably fresh, a pace of 10 to 20 percent slower than marathon race pace (MRP) is ideal because it is hard enough to provide a strong training stimulus, but requires only two to three days of recovery. The pace can start off casually, but after half an hour you should be running no more than 20 percent slower than your MRP. Over the course of the run, increase your pace until you are running roughly 10 percent slower than MRP for the last half hour or so.
Long runs in this intensity range use similar running form to marathon pace, which prepares your muscles specifically for the demands of a marathon or other long race. Compared to long runs at a slower pace, this intensity range uses more glycogen, which provides a greater stimulus to increase your glycogen stores. It also develops your body's ability to use the optimal blend of fat versus carbohydrate at close to marathon pace.
2. Learning to handle marathon race pace: The most specific marathon preparation you can do is a long run at MRP. These workouts provide a powerful training stimulus, but are also dangerous in that they require more recovery than slower runs and have an inherent risk of injury. Two to three long runs at MRP during the last 12 weeks before a marathon (with two recovery days before and three to four afterwards) should achieve the desired training effect without unduly increasing your risk of overtraining or injury.
Another effective method of marathon pace training is to start your long runs comfortably (two to three minutes per mile slower than MRP), and pick up to MRP for the last hour or so. This is an excellent way to simulate the last 10 miles of the marathon—running at MRP while fatigued—while reducing the recovery time.
3. Balancing endurance and recovery: If you work Monday to Friday, you will frequently need to do key training sessions on both Saturday and Sunday. After a race or hard workout on Saturday, your Sunday long run should be at a relaxed pace because you will be tired and have stiff muscles, which increases your likelihood of injury. If your muscles loosen up as the run progresses, you can increase the training stimulus by increasing your pace to about 20 percent slower than MRP.
How long should your long runs be?
That depends on what distances you are preparing to race and how much you have been training. The farther the race, the greater the physiological adaptations necessary for success, and the longer your long runs need to be.
|Goal Race||Longest Run (miles)|
|Marathon (Goal: to Finish)||20|
|Marathon (Goal: Personal Best)||22|
Goal Race Longest Run (miles)
Half Marathon: 16–20
Marathon (Goal = to finish): 20
Marathon (Goal = personal best): 22
The probability of injury increases significantly as runs go beyond 20 miles. When your muscles are highly fatigued, they lose their ability to absorb impact forces, which increases your risk of muscle strains, tendonitis, and even stress fractures. In addition, running technique tends to deteriorate towards the end of long runs, which can further increase the likelihood of injury. Novice marathoners with the goal to finish should include no more than one to two 20-milers in their marathon training. To be optimally prepared, more experienced marathoners should put in about five to eight 20-milers, including two to three runs of 22 miles. The last 20-miler should generally be three weeks before the marathon.
How often should you run long?
Because the adaptations to long runs are cumulative, most runners should do a reasonably long run most weeks, except during recovery breaks. Your risk of injury and overtraining increases, however, if you do too many taxing long runs. By judiciously building the various intensities discussed above into your training plan, you can optimize your race preparation. Two patterns that work well are to alternate weeks of harder and easier long runs, or to do relatively strenuous long runs two weeks in a row, followed by a shorter, easier long run the third week. Similarly, when you are increasing the distance of your long runs, adding one mile per week, with a shorter run every third week, lengthens your run fairly quickly while giving your body time to adapt to the load.