A serious racer should use a variety of 3-4 "standard" types of speed training to prepare to race his or her best at any distance from 5k to marathon. What changes with race distance is the mix of different speed workouts. The following reflects my opinions based largely on what I have gleaned from my two favorite running reference books, "Daniels' Running Formula" by Jack Daniels and "The Competitive Runner's Handbook" by Bob Glover, plus my personal experiences in 17 years of training and racing.

There are several body "systems" or features that, together, determine how fast you can run for a given distance. Each has to be developed to enable your maximum race pace ability. Let's call these the "goals" of speed training. These goals are:

1. Improve anaerobic threshold (AT) or lactate threshold (LT), which determines pace at which you go into the anaerobic zone and lactic acid begins to build up in your muscles, which causes fatigue and reduces muscle fluidness.

2. Increase aerobic capacity or VO2Max, which is a combination of maximum oxygen uptake and your body's ability to process the oxygen to muscles where it's needed to burn glycogen and fat for energy.

3. Improve running economy, running strength, and anaerobic capacity. Running economy is how efficiently you use oxygen when running at a given pace. That's not the same as aerobic capacity. Increased running economy permits you to utilize a lower percentage of your aerobic capacity at any pace. Running strength is your body's overall ability to handle "overload" demands, as well as to stay within the "comfort zone" at faster paces. Anaerobic capacity is your ability to run without sufficient oxygen or to hold pace and form outside the "comfort zone."

4. Condition and program your body and mind to run at race pace.

There are 4 basic categories of speed training to accomplish these goals. I'm going to use Jack Daniels terminology because I think it makes it easier to relate the categories to the above goals.

1. Threshold training. These are tempo runs and cruise intervals which improve the anaerobic threshold. They are run at 85-92% of maximum heart rate (Hrmax) or AT pace, which is reached at 10-20 sec/mile slower than 10k race pace. A tempo run is simply 20-40 minutes of running at AT pace. For most of us, that translates to 3-6 miles. It's best to do them on fairly level ground so you can better control the pace. If your route requires that you run hills and you don't use a HR monitor, just adjust the pace so that it "feels" like AT pace. Cruise intervals are a substitute for a tempo run. They are 800m to 2 mile intervals at AT pace with brief recovery, like a minute or less, between them. Keeping the recovery periods very short permits blood lactate levels to remain fairly constant so that you experience a threshold effort throughout the session. The advantages of the breaks are that they permit you to do a little more threshold running (like 4 miles instead of a 3 mile tempo effort) while still making the session a little easier mentally than a tempo run since you have the breaks to look forward to. I seldom do tempo runs, but mostly use 1 and 2 mile cruise intervals instead, mainly because my brief breaks are to drink water, which I do at least every couple of miles even when doing speed training.

2. Intervals. These are for VO2Max, or aerobic capacity, development. They are 400-1200m (440-1320 yard) intervals at 98-100% of HRmax or about 5k race pace with recovery time equal to or slightly less than interval running time. The trick here is to recover sufficiently to be able to complete the session at the target pace without making it an "all out" effort, but also without recovering fully between interval workbouts. One of Glover's guidelines is to recover to a heart rate of 120. Glover also allows these to be run over a pace range of 5-10k pace and for as long as 1 mile, depending on the stage of a training cycle you are in. Intervals are considered by many as the bread and butter of speed training. Yasso 800s are simply a special form of intervals used for a specific reason....to verify your aeroic capacity readiness to run a particular marathon time. However, doing them successfully doesn't mean that your endurance, AT and running strength/economy are adequate to support the pace over the full 26.2 miles.

3. Repetitions. Glover calls them power intervals. They are short, fast intervals which improve anaerobic metabolism, as well as running mechanics, strength and economy. Usually 200-400m (220-440 yard) repetitions faster than 5k race pace, but not an all out sprint, with very long, full recovery. Daniels guidelines call for a repetition pace of 6 seconds faster per 400m than interval pace (that's 24 sec/mile faster than 5k race pace) and recovery times as long as 4 times the rep time. Glover says to recover up to 5 times the rep time. These are fast and hard. But short enough to stay relaxed through them. They call into play the fast twitch muscle fibers that not only help you to run faster, but also play a large role in determining running economy.

4. Marathon Pace runs. Obviously, these are intended to practice race pace so that your body and mind become comfortable with it. They are usually 6-13 miles at marathon pace, but can be as long as 18-20 miles for experienced marathoners. You only have to do a couple of them late in a marathon program. Race pace training for shorter distances doesn't make a lot of sense….at least not over continuous, extended distances. Such training would quickly approach being a race effort. It's better to "train" at race pace for shorter distances by racing frequently. There is more flexibility to run a lot more races in a shorter distance program than there is in a marathon program. Also, there is plenty of race pace running in the intervals.

Daniels also provides guidelines on how much of weekly mileage should be comprised of the first three categories. He says that threshold running can be up to 10% of weekly mileage, intervals up to 8% and reps up to 5%. In other words, the harder and faster the speed work, the lower the percentage of weekly mileage it should be. Of course, you shouldn't do all three types in any one week. One or two speed sessions per week is enough hard work for any of us. In weeks that include a race, only do one speed session and make sure it's at least 3 days before the race. And, obviously, all other running, including long runs, should be in the "easy" range of 70-80% HRmax or 1-2 minutes per mile slower than 10k race pace.

There are lots of variations of these 4 basic speed work categories. Hill repeats, for example, which are intervals run on hills. Daniels considers them to be a form of Repetitions and prefers they be done on a treadmill so the incline can be precisely controlled. Glover considers them to be a key element of the strengthening phase of a training program and talks extensively about them in his book. He defines categories of long hills (a quarter mile or so) and short hills (50- 200 yards), with the short hills twice as steep as the long ones. He recommends that both be run anywhere from repetition pace to 10k race pace, depending on your level of ability, but the short ones faster than the long hills. Hill repeats are great for improving running strength and economy. I can verify from my experience that hill training will go a long way to make you a faster runner and stronger marathoner.

Fartlek, the Swedish word for "speed play", is simply a less structured form of any of the speed work categories and can include a mix of them. Fartleks are a good way to introduce speed work into each training cycles or to provide a little "break" from the rigors of a training program while still deriving speed work benefit.

There are lots of other variations of speed training....ladders, pyramids, cutdowns, cut times, cruise repetitions, rolling hills fartlek, long run tempo, and others. All are forms or mixes of the 3 basic categories of threshold, intervals, and repetitions.

Some speed training categories provide other training benefit in addition to that for which they are primarily intended. For instance, intervals not only develop VO2Max, but they also help lower AT. However, that doesn't mean that threshold runs should be eliminated and replaced with intervals to get a "double bang" for your effort. Intervals aren't as efficient as tempo runs for developing AT. Since intervals are harder and run a lot faster than threshold pace, you can't run as far at interval pace as you can at AT pace in a single session. It's for that reason that Daniels recommends that they be a lower percentage of weekly mileage than threshold running. The best approach is to include the optimum balance of speed training categories in any training program.

In scheduling speed work into a training program, I use a few guidelines:

1. Three of the four categories should be included in every training program from 5k to marathon. The exception is Marathon Pace runs, which is only used in marathon training.

2. The shorter the race distance you are training for, the more emphasis should be placed on Repetitions.

3. The longer the race distance you are training for, the more emphasis should be placed on threshold (AT) training.

4. Intervals (VO2Max or aerobic capacity training) play an equally important part in training for all distances.

For example, in training for a marathon, which is raced mostly in the aerobic zone, I try to schedule up to 50-60% of my speed work as threshold runs, 30-40% as intervals and 10% as repetitions, plus a couple of MP runs. For 10k training, where race pace is slightly anaerobic but not quite at aerobic capacity, it's more like 30% threshold, 50% interval and 20% repetition with more frequent speed sessions, since total mileage and long runs are less than in a marathon program.

For more details about speed training, I would strongly recommend the two references that I mentioned earlier.....Daniels book, "Daniels' Running Formula" in which he does an excellent job of explaining the categories of speed work, what each does for you, and determining pacing for speed work.....and Glover's 1999 edition of "The Competitive Runner's Handbook," which is a very comprehensive guide to training for all distances from 5k to marathon.

Jim2