The Cooper Institute
 

Founded in 1970 by the "Father of Aerobics"
Kenneth H. Cooper MD, MPH

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Improve Your Pace with Interval Training!

Posted in
Live well

Thursday, Jun 18, 2015

For well over a century, a cornerstone for middle distance and endurance competitors has been long slow distance (LSD) training. In addition to performing LSD, these individuals also perform interval training (IT) on a regular basis. IT is best described as alternating high intensity work periods (intervals) with low intensity work periods (recovery) within the same workout. The pace that the intervals are done at is usually slightly faster than or at goal race pace. There are an infinite number of variations for interval training workouts. The distance covered as well as the time for each interval, the number of intervals and recovery time between intervals can all be manipulated according to current fitness levels and goals. Here are two examples: A casual competitive 5K runner with a personal best time of 21 minutes might perform an IT workout consisting of 5 x 400 meter intervals in ~95 seconds each with 90-120 seconds of recovery between each interval. On the other hand, a world class 5K runner with a personal best time of 13 minutes and 30 seconds might perform 20 X 400 meter intervals in ~65 seconds each with 60-90 seconds of recovery between each interval. Either way, everyone agrees that IT days are very hard!

Over the past decade, a training approach called high intensity interval training (HIIT) has been shown to provide many of the favorable changes associated with LSD training in a significantly shorter period of time. Rather than doing each interval at a speed slightly faster than goal race pace, the individual does each interval at a maximal or near-maximal level of effort for a much shorter period of time. A HIIT study in the Journal of Applied Physiology has generated a great deal of attention. Researchers at the University of Copenhagen worked with 18 moderately trained men and women runners with an average V02 max of 52.2 ml/kg/min. Their average weekly running mileage was about 19 miles. They were split into a 10-20-30 group and a control group for 7 weeks. The control group continued their normal training regimen (~19 miles/week of LSD). The 10-20-30 group replaced all of their training sessions with the following program. For 30 seconds, they jogged very slowly (<30% of maximal intensity). This was immediately followed by moderate running (<60% of maximal intensity) for 20 seconds, which was immediately followed by high speed running (>90% of maximal intensity) for 10 seconds. This pattern was repeated 4 additional times for a total running time of 5 minutes. A two minute recovery period was then allowed before repeating the 5 minute cycle 3-4 additional times. This is shown more clearly below:

Jog 30 seconds, run 20 seconds, sprint 10 seconds. Repeat 4 times.

2 minute recovery

Jog 30 seconds, run 20 seconds, sprint 10 seconds. Repeat 4 times.

2 minute recovery

Jog 30 seconds, run 20 seconds, sprint 10 seconds. Repeat 4 times.

2 minute recovery

Jog 30 seconds, run 20 seconds, sprint 10 seconds. Repeat 4 times.

Total running time (not counting recovery): About 20-25 minutes per workout. They performed this workout ~3 days per week and did not perform any other training during the 7-week training period.

Following the 7-week training period, the 10-20-30 group had a 4% improvement in their V02 max, as well as a 21 and 48 second improvement in their 1500 meter and 5000 meter race times, respectively! All of the changes were statistically significant. There were no significant changes in the control group. Of interest, the 10-20-30 group actually decreased their training volume by ~50% (19 miles per week prior to the 7-week training period versus 9 miles per week during the 7-week training period). As a bonus, both resting systolic blood pressure and LDL cholesterol level decreased in the 10-20-30 group as well, with no changes in the control group.

To summarize, this study showed that interval training with 10 second near-maximal intensity bouts can improve V02 max and performance despite a ~50% reduction in the volume of training. So, rather than suffering through repeat 400 and 800 meter intervals, you might want to give the 10-20-30 approach a try on your interval training days and on some of the days where you might otherwise do LSD.

A word of caution though: You are much better off from an injury prevention standpoint to perform hard running on a forgiving surface such as level grass, a dirt trail, a track, or a good quality treadmill. To give your knees and low back a break, try to stay off the asphalt and concrete. Be sure to get in a good warm-up and cool-down as well.

To learn more, register for our Interval Training course – fitness professionals and the general public are welcome.

 

References

Gunnarsson TP, Bangsbo J. The 10-20-30 training concept improves performance and health profile in moderately trained runners.  J Appl Physiol. 2012. May 3 (Epub ahead of print).