Role of Interval Training

Interval training and speedwork are two entirely different things. Keeping in mind that long distance running is mostly aerobic, therefore the ability to sustain pace above anaerobic threshold is important. Speed is much less important and requires short bursts and power building not needed in endurance running.

Lydiard said that intervals are “tiring, exacting work”. These workouts are designed to be uncomfortable at paces well above anaerobic threshold with enough recovery between to get through the workout holding good form. In doing this the body gets exposed to acidosis which you will encounter at the later stages of your race. The end goal is to increase the body’s ability to buffer acids so high rates can be maintained for a long period of time.

Generally speaking, an interval workout can be structured by repeats of 400m, 800m, 1200m and 1600m. Usually 5000m to 7000m in total with each interval being the time it takes for heartrate to come down to 130 bpm. On Lydiard the athlete is given a pace chart which indicates effort pace for ¼, ½ and ¾ effort. The first couple sessions are done at ¼ effort with subsequent ones being taken up to ½ or ¾ effort. The distances can be varied depending on feel and mixing it up to keep it interesting.

I remember one of my more difficult interval sessions leading into marathon. While I wouldn’t recommend this for most, for me it was a workout that really helped me get accustomed to acidosis overtime and mentality forced sustaining pace. As the log picture shows the workout was 35x440yard intervals with 110yd jog recovery. About 8 miles of sustained pace averaging 75 seconds, no faster. Always did a good warmup and cooldown and then the next day was long slow running for recovery. Also remember before doing these types of workouts I had built a strong aerobic base and had prepared my muscles with 4 weeks of hill strengthening so I was ready to do this type of work. And again, 75 seconds for 440 yards is not “speed” but sustained fast pace. Sometimes intervals were 1-mile repeats on the road at 5:00 mile pace.


Intervals are an important part of endurance training but must be done in sequence and the body must be ready. Each workout is structured for the individual based on where they are in their training and how they are feeling. And don’t mistake them for “speedwork” they are and have an entirely different purpose.

Here at Running Niche we are trained Lydiard level I & II coaches. Please stop in the store to learn more about the Lydiard Method. We can help you sign up. While your personalized plan costs $100, and goes to a non-profit, we provide the day to day coaching at no additional charge.

Bob Dyer (Co-owner, Running Niche)
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