You have all run 10K races. Running 15 seconds per mile slower than 10K pace should require only a moderately intensive effort to maintain pace. The drawback is you will be running 3 miles at threshold pace without resting up. Running a quality yet not intensive workout on slightly tired legs is called TRAINING. Practice running relaxed to gain the benefits mentioned last week at:
Tempo running, or anaerobic threshold pace training is the key to strength endurance in 10K preparation. Threshold pace training is also called Tempo Running, Sustained Running or the unfortunate Continuous Hard Running. Moderate intensity with comfortably hard running should make you delete hard running from your vocabulary. You run slower than 10K pace, you run for less than 10K, and you usually break the session into repetitions, so clearly this is a gentle session. Cruising long Intervals at 15K or 10 mile race pace--about 10-20 seconds per mile slower than 10K speed, running slower than 10K speed will actually improve your ability to run a great 10 kilometer race. Sounds far-fetched doesn’t it! Yet slowish running at 65-70 percent of maximum heartrate improved your aerobic ability, your VO2 max, when you ran a minute to one and a half minutes per mile slower than 10K pace. Likewise, running about 15 seconds slower than 10K pace will improve your anaerobic threshold, the point at which you produce ever increasing amounts of lactic acid. According to Jack Daniels Ph.D., researcher, coach of the over achieving State University of New York at Cortland cross-country team, and author, “Anaerobic Threshold is the pace or intensity beyond which blood lactate concentration increases dramatically, due to your body’s inability to supply all its oxygen needs.” Daniels continues. “Physiologically, threshold training teaches muscle cells to use more oxygen--you produce less lactate. Your body also becomes better at clearing lactate.” Threshold pace running conditions your muscle fibers to a faster pace. You build leg strength and improve your running biomechanics by testing the limits of your aerobic system. Because you’re running at a fast pace for a moderate distance, you develop speed endurance by bringing in more of your fast twitch muscle fibers. As coach Roy Benson says, you teach “motor responses to more of the muscles...used in racing.”
At threshold pace, the mitochondria in your muscle cells can no longer meet all of your energy needs. Your body switches to the anaerobic system--you produce energy in the fluid surrounding the mitochondria. You produce lactic acid as a by-product to anaerobic threshold running. Practice running at threshold pace often enough and you will adapt to running with a higher level of lactic acid in your muscle cells and circulatory system. But you will also excrete more lactic acid.
The point at which you produce excess lactic acid is your red line. If you run faster than red line pace, your body will soon force you to slow down. In the early stages of threshold training your red line will probably be 80 percent of max HR. According to Daniels, “As you get fitter, your red line rises from 80 percent of maximum heartrate to 90-95 percent. Race day red line speed rises.” Run faster than red line pace and your form is likely to fall apart. Run your first couple of threshold sessions at 80-85 percent of max HR, or about half marathon pace. Then ease to 15K pace for future sessions, about 10-20 seconds slower than your current ability at the 10K.
If you are running six to eight threshold pace sessions, try: 3 x one mile one time 3 miles 2 x 1.5 miles all at the modest pace described above. Then repeat the three sessions at closer to 15K race pace. One useful trick is to run the first half mile at half marathon pace , then speed up to 15K pace. Thinking about the running form hints in Week Two will help you become more efficient at running. Advanced runners should use the long hill reps and cross-country running at anaerobic threshold at Week Fifteen to complete their threshold training
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