Intervals Are For All Runners

 “I encourage you to use the term “interval” correctly.  The interval is the rest/recovery period between the repetitions.  In the case of 10 x 400m with 60 seconds recovery, the interval is the 60 seconds, not the 400m (the 400m is the repetition).  If your recovery between repetitions is a 60 second walk, then saying that you’re going to the track “to run some hard intervals” is incorrect.”
Jay Johnson, running coach

Intervals are indeed for all runners. Track coach, Bill Bowerman, assigned a weekly interval workout when introducing running to adults and with his university track team for: 1) developing speed, and 2) learning pace judgement. In considering intervals, Bowerman said, “If you are unaccustomed to intervals, start with a series of 100 meters with adequate breathers between each. You should do as many of these as seem stimulating but not exhausting during any one workout. Do not exceed one mile of total intervals during your first week, but gradually work up to covering approximately three miles. The length of the intervals may also be increased from the 100 meters to 200 and then 400. They may be done in sets such as 100, 200, 400, 200, 100. The pace of each set may be varied from slow, medium, to fast.” 

How Did Intervals Originate?
Like Bowerman introducing running to adults, the origin of intervals starts with the partnership between a track coach and a cardiologist. Unlike Bowerman’s situation, the cardiologist approached the track coach to develop an exercise program to rehabilitate coronary patients on his caseload. In the 1930s, German running coach, Woldemar Gerschler, along with cardiologist Dr. Herbert Reindel, did  a three-week experiment involving 3,000 subjects on the effects of interval training.  The idea of Gerschler’s interval program was that you stress the heart until 180 beats per minute, after this you allow it 1 minute and 30 seconds to get back down to 120-125 beats per minute. Gerschler believed that the heart was trained and adapted during the rest interval, not during the stressing of the heart part.  Therefore he thought the recovery was the main emphasis. As the runner progresses with interval training, rest should decrease naturally as your heart rate should recover faster, the more fit you are. 

The results from the Gerschler & Reindel experiment showed an increase of 20 percent in heart volume and increase in cardiac output (amount pumped by the heart) in research subjects. Applied to running, interval training resulted in numerous world records on the track. In fact, Roger Bannister broke the 4-minute barrier and set the world record off an interval training program.

Intervals Build Endurance
Not only have running coaches used interval training for running faster, they’ve also used it for running farther. For instance, the Running Room, in it’s training programs, uses 10 & 1s to gradually build endurance; in which after 10 minutes of running, a 1 minute walk interval takes place. Also, time running and recovery intervals can both be altered to suit a runner’s current running fitness, such as, 30 seconds of running followed by a recovery interval of 30 seconds of walking.

Location of Intervals
Interval workouts most often take place at a track, but it's certainly possible to do this workout in other locales.  The advantage of track workouts is that the distance is clearly and accurately marked, i.e., when doing a workout of 400m of running and a recovery interval of 400m, the runner knows that this is one lap around the track. Nevertheless, in this era of smartwatches with gps capability, it is possible for the runner to measure out this distance on a road or trail course, prior to an interval workout.

Warming Up For & Cooling Down From Intervals 
Always start an interval workout with a good warm up. Run for 2k at a comfortable pace. Do some stretching and 4-5 strides. Strides are 60m-80m sprints. Roll into these, gradually picking up the pace to about 90% of full speed before decelerating. These help you get the muscles warm before the workout. End with a 2k cool down easy run.

While interval workouts have advantages, there are drawbacks too. One is risk of injury, so runners need to be extra aware of body signals during interval workouts. Another disadvantage of intervals is that the constant repetition of short distances invites boredom or mental staleness. Finally, although interval training serves some purposes, it does not provide total conditioning nor the necessary practice of sustained running.

Thanks for reading. Intervals are one way to add variety to running, next post will discuss another form - fartlek running. If you enjoy these posts and would like for them to automatically go to your email inbox follow Experiment of One Coaching and 'like' us on Facebook.

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