Part 1 of this two part post discussed beginner marathon training programs and the elements typically included in them. This post will cover the types of workouts usually seen in intermediate or advanced marathon programs (in addition to the previous types of workouts, which are still a backbone of the training schedule).
Where the goal in beginner programs is usually to get a runner through the experience comfortably and successfully, the goal in more advanced marathon programs is usually to improve upon a previous marathon performance. The runner does not just want to finish; he or she wants to finish faster. Therefore, the new addition in these programs is workouts meant to improve pace. These workouts generally are worked into the schedule by replacing some of the easy aerobic days and/or replacing a cross training day with a running day.
There are two main types of workouts meant to help runners improve their performances relative to marathon pace. These are lactate threshold workouts and interval workouts. Each works to improve different aspects of a runner's speed.
A Little Physiology: It is not my purpose to go deeply into physiology in this post, but you do need to understand a bit about how the body produces energy while running to understand the two types of speed work. This is a very simplified version of the explanation, but hopefully it will be enough. If you want a deeper explanation, two good training books to look at are Daniels' Running Formula or Advanced Marathoning by Pfitzinger and Douglas. These are two training books that intermediate and advanced marathoners should consider reading. They both contain excellent training plans for more advanced marathoning, and much of the information in this post is based on information from these two books.
When the body is doing activity, it has two ways to produce energy at the cellular level to move muscles, aerobically (with oxygen) and anaerobically (without oxygen). Aerobic energy production is going on constantly in our body and is what you are using when you are running your marathon and doing your marathon training.
Both of these types of energy production create waste products called lactate in the cells and bloodstream that the body has to dispose of. In low intensity aerobic activity your body can dispose of these waste products faster than you are creating them, so these wastes do not inhibit your ability to continue running. If you are running aerobically at an easy pace you can literally run for hours and hours without these wastes becoming a limiting factor in your performance, which is exactly what we strive for in our marathons.
Anaerobic metabolism is not as efficient as aerobic metabolism and creates larger amounts of waste products, more than the body can eliminate efficiently. Therefore, when you are working anaerobically, you are on a very short time clock. Eventually, depending on how much of your energy production is being done anaerobically, the waste products will accumulate in the cell which will inhibit the function. The maximum amount of time a body can work with most of its energy coming from anaerobic sources is about four minutes, so anaerobic metabolism is not usually a factor in distance running (although you may dip into the anaerobic system in a finishing kick in a distance run).
Marathoners want to train their aerobic system without moving into anaerobic metabolism. Every runner's body has a maximum limit of how much energy can be produced by their aerobic system. This upper limit in the body's ability to produce, transport, and use this energy is called the VO2 max, and this is what runners train in interval workouts. You never actually use this pace in marathon running, but by pushing back this upper end, the pace at which you can run comfortably also gets faster. It shifts the whole range of paces that are comfortable for you to run.
As you speed up from an easy aerobic pace but before you reach maximum production, you will eventually get to the tipping point in waste removal, where you are producing more waste than you can remove. Once you get past this pace, you will eventually limit your ability to continue when you have collected too much waste to clear effectively, and you will have to slow down to allow the bodies waste disposal to catch up. This tipping point is called the lactate threshold. However, the good news is that this process can also be improved with training so that runners can push back the pace at which the lactate threshold occurs. That is the goal of lactate threshold training.
Now that you understand the basic physiology, let's look at how these get worked into marathon training.
Lactate threshold (LT) workouts: Almost all intermediate and advanced marathon programs (and even some beginner programs) will include this type of workout. Pfitzinger and Douglas call this "the most important physiological variable for endurance athletes." In these types of workouts you are meant to run at a pace that is just under the lactate threshold for a particular period of time. Stimulating the body in this way causes the body to adapt to make this level of effort easier and more efficient, which pushes back the pace at which the lactate threshold occurs.
The key component of this type of training is not to run too fast. If you run faster than your current lactate threshold, then you will not produce the desired adaptations. The tricky thing with this type of training is determining that pace. It can be done scientifically in an exercise lab by taking blood samples, but most runners don't determine it that way. Most programs that include threshold training will either include a chart by which you determine your threshold workout pace based on a previous race effort, such as Daniels' VDOT charts. Others will tell you to run it at a pace that is roughly equivalent to your 15k race pace or that you could sustain for an hour without slowing down. For me this pace tends to come out to about 15 seconds per mile slower than my half marathon race pace.
The lactate threshold runs in your marathon program will usually be of one of two types. The most common is usually called a "tempo run" and involves up to 20 minutes of continuous running at LT pace. These should be done over fairly flat courses, and your goal should be to hold steady at your LT pace. In these workouts, it is better to go a little under the goal LT pace than it is to go too fast. This pace should be comfortably hard but sustainable. Besides the physiological training, they also train you to focus and develop self-discipline in pacing. You should not have to slow down toward the end of these workouts. If you do, you went too fast.
The second type of LT run that may be included is called "cruise intervals." These were popularized by Jack Daniels and have been incorporated into many marathon programs. These are shorter periods of tempo running, such as 5-15 minutes, with a short rest, usually one minute, in between. These workouts allow runners to spend more time running at threshold pace because of the short breaks that allow runners a bit of physical and mental recovery.
Many intermediate programs include LT workouts either every week or every other week. These are my favorite workouts, and I look forward to them. I always feel fantastic after these workouts, and you should too if you don't run them too fast. These workouts have a big payoff with a very low risk of injury. If you have not been doing these type of workouts in training, you will see improvements in your racing times at all distances by adding these in.
Oh geez, although I originally thought that this information on marathon training would be a two part post, I can tell from the length of this, that I am going to need a Part 3. This was already a lot to take in. I am going to stop now. The next post will cover the second and more demanding type of speed work, interval training. It will also mention other miscellaneous types of workouts that may pop up in your marathon program, such as marathon paced runs and strides. I hope you will come back midweek for the final post inthe marathon training series.