Posted: March 14, 2006

Athletics: Anaerobic Threshold Training

Anaerobic Threshold Training or anaerobic turnpoint running is usually the third element for preparing to race at 5-K or longer. You will usually run some base mileage, and then add hill running before running a series of sessions to stimulate your anaerobic threshold to rise. You’ll be running some hill sessions during this phase too.
According to Jack Daniels Ph.D., researcher, coach of the State University of New York at Cortland cross-country team, “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.”
“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 running biomechanics by testing the limits of your aerobic system. You become an expert at using or getting rid of your lactic acid. (Lactic acid is converted to glucose, which is the most desirable fuel for your muscle and brain cells.)
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 and teach motor responses to more of the fibers used in racing.

Anaerobic threshold pace training means running at 10 to 20 seconds per mile slower than current 10K racing speed. It will teach you to stride rhythmically at good pace and improve your ability to race faster.
Threshold is also the pace which you can sustain for about 50 to 60 minutes. For some of you it will be 10K or 5 mile race pace. For the elite, it’s close to half marathon pace. For this web page we will assume it’s 15K or 10 mile race pace.

Anaerobic Threshold Training Builds Stamina.
* Expands your capillary network.
* Increases your muscles’ enzyme activity.
* Educates your muscle cells to tolerate higher levels of lactic acid.
* Yet you educate your cells to excrete, redistribute and re-use lactic acid faster.
* You further increase your VO2 maximum.

Threshold Running Improves Form.
Concentration on running form improves, giving increased running efficiency with less wasted effort.
Further strengthening of your running muscles as you bring in more of your muscle fibers to maintain this fast pace.
Improved coordination at higher speeds...if you pay attention to your running form: you cannot just float effortlessly along. Threshold pace running also prepares you for the stresses of racing.

At threshold pace, the mitochondria in your muscle cells can no longer meet all of your energy needs. Your body partially switches to the anaerobic system and you produce energy in the fluid surrounding the mitochondria. Lactic acid is produced as a by-product to anaerobic running. Practice running at anaerobic threshold pace often enough and you’ll adapt to running with a higher level of lactate or lactic acid in your muscle cells and circulatory system. You will also excrete more lactic acid.
The point at which you produce excess lactic acid is your red line or lactate turnpoint. If you run faster than red line pace you’ll feel a burning sensation in your muscles and your body soon forces you to slow down. In the early stages of threshold training your red line will probably be 80 percent of maximum heartrate. As you get fitter, your red line rises 90-92 percent.

Running anaerobic threshold sessions for the first time? Do not worry. Threshold training is gentle speed running, and starts with innocuous sessions such as 4 times half a mile at your half-marathon race pace. You’ll run at least 25 to 37 seconds slower than 5K pace.
After each half mile effort, run easy for a minute or two before easing up to half-marathon speed again.
These intervals are often called cruise intervals because you cruise along at modest effort. While 10K race pace can be gruesome, long reps at half-marathon pace and eventually slightly faster are a delight. You’ll still feel fresh after a few repeats at this modest pace.
According to Lore of Running, by Tim Noakes, half of your improvement in lactate threshold or turnpoint comes in the first 10.5 days, but it takes 12 weeks at a certain mileage per week to reap your full gains. You can increase your threshold from 63 to 71 percent of your VO2 maximum, allowing you to run faster at your threshold and thus faster at 5K, 10K, to the marathon. It will take another 12 weeks at X mileage to reach your VO2 maximum.
The next time you increase mileage by 5 to 10 miles per week it will again take 12 weeks for maximum threshold improvement and 24 weeks for max VO2 increase, but only 10.5 days to get half of your anaerobic threshold increase.

FYI: In the second 24 weeks you would probably choose to run 2 to 4 of your extra 10 miles at good speed as fartlek, threshold intervals and some at 5K pace to further increase your economic running skills and endurance.

Gentle Transition to quality miles.
The trusty overload principle requires runners to increase training by adding mileage, or by running faster. While your long run may increase by two miles in this phase, the real goal of the anaerobic phase is to get you running at sustained pace for several miles. Adapting to a faster running pace for 3 to 5 miles each week makes your legs, your entire running system stronger.
Run half-marathon pace before 15K pace, and add half a mile of threshold running every other week until you reach 10 percent of your weekly mileage in one session. There’s no excuse for running at the same pace day after day.

Low mileage or novice runners benefit even more from speed running than moderately high mileage runners. Running moderately fast teaches you to run with good form. It’s vital for low mileage runners to be economical with their energy. The low mileage runners schedule on this web site and in David Holt’s books contain the same percentage of speedwork as the schedules for high mileage runners! There’s no reason to deny yourself speed sessions because you run low mileage.

After a few sessions of half miles as described above, you can graduate to mile repeats. Mile repeats at 80 percent maximum heartrate, provided you run them in control, are a very relaxing way to get used to threshold pace running. Mile reps are a great benchmark for threshold training, and will prepare you for your Tempo runs, which are continuous runs of 3 to 4 miles at 40 to 45 seconds per mile slower than 5-K running pace.
You’ll move up from that modest 4 times half a mile in one session to reach 4 times one mile over a 12 week period. Your weekly sessions will go along these lines.

Week one: 4 x 800 meters with a 200 meter walk as recovery. To avoid aches, go no higher than 80 percent of maximum heartrate.
Week two: 3 x 1,200 meters with a 400 rest. Check your heartrate monitor at 800 and slow down a bit if it’s over 80 percent.

Week three: 5 x 800, but jog the first 50 meters of the rest before easing into a walk.
Week four: As for week two, but jog the first 100 meters of the rest, walk 200 and then jog the last 100 before starting the next rep.
Week five: Race at the 5K, which means 30 seconds per mile faster than these 4 training sessions at threshold pace. This is fun and reminds you that training is easy.

Week six: 6 x 800 but you’ll jog the entire recovery slowly.
Week seven: 4 x 1,200 and allow your heartrate to reach 85 percent of maximum for the last lap instead of slowing down. You will jog most of the recovery.

Week eight: 3 x one mile or 1,600 meters if at the track. Accept the fact that the 4th lap will take your heartrate to 85 percent of higher, but make sure you pace yourself to stay below that level until close to the end of lap three. Jog at least the first and last 100 of a 400 meter recovery.

How soon you add an additional half mile to a mile is up to you. You can reduce the recoveries before adding distance, or if your goal is the 5K, you may never feel the need to run more than the sessions of week 6 to 8.

As your physical running form improves and as your ability to distribute and re-use lactic acid also improves, your running speed will increase at 85 percent of your maximum. Eventually, you may become so proficient that you can train at 90 percent of max heartrate, yet still be at anaerobic threshold.

Half-marathon pace is called Lactate Threshold Velocity, the fastest pace you can run without the build-up of lactic acid. As you need to experience some lactate build-up, you’ll do most sessions at 15K pace or the pace you can handle for a 50 to 60 minute race.

You’ll produce less lactic acid if you run a few 100 striders before the threshold repeats. These are speed sessions so naturally you’ll run an easy mile before and after each session. It will take a few weeks for your muscles to adapt to anaerobic threshold training. Give your muscles time to adjust by running 40 seconds per mile slower than 5K pace during early sessions, and then as the weeks progress, allow your pace to increase to within 27 seconds per mile of 5K pace.

You’ll probably run your threshold sessions on a Saturday, and run easy, but fairly long on Sunday, covering about twice the mileage of Saturday most weeks.

Monday will be a recovery cross-training day.

Tuesday and Thursday will be relatively easy runs at 70 percent of maximum heartrate during this phase. High mileage runners will run up to 10 miles, but the 20 to 30 mile per week runners will do 4 to 5 miles.

Wednesday will be your other speedy day. You’ll maintain leg strength with hill repeats twice a month, which will also keep your legspeed up. The other two weeks will be 2 miles of 100 to 300 meter striders at 10 to 15 seconds per mile faster than 5K race pace for running form and to keep your entire system ready for Interval training.

Copyright David Holt 2006 - Posted with permission

Adapted from 5K Fitness Run, ISBN 0965889750 by its author David Holt, Get 230 pages for $14.95, from Amazon.com

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