Interval runs are used by many runners to not only improve fitness, but also to break up the repetitiveness of running at the same pace for an extended period of time. There are many ways that interval runs can be used, and some are more effective than others. By focusing on the right kind of interval workouts you can make vast improvements in your running.
What are Interval Runs?
Interval runs alternate high intensity segments of work with low intensity segments of recovery. The recovery may involve running, walking or rest. The intensity of the work will depend on the fitness of the runner and the purpose of the workout.
Why are Interval Runs Effective?
It may seem obvious, but by breaking the run into shorter segments, you can run at a higher intensity for a longer total period of time. So for example, if you are working to improve your 5k pace, you can do a workout that involves more than 5,000 meters of high intensity work at your 5k pace. You could also run faster than 5k pace for 5,000 meters. The recovery segments will allow you to be able to run faster or longer than in a 5k, which will ultimately help you to build your speed and endurance.
Interval runs are are helpful because they can lead to an increase in aerobic capacity, or VO2 max. This is the maximum rate of oxygen consumption during incremental exercise and can indicate how efficiently an individual uses oxygen while exercising.
How Long Should Interval Workouts Be?
In the 1960s Swedish physiologist Per-Olof Åstrand found that interval segments three minutes long led to very high strain including high heart rate and blood lactate values. However, if the segments were reduced to two minutes there was significantly less strain even when the total amount of workout time and intensity was the same. This means that it can be beneficial to keep the high intensity portion of an interval workout to less than two minutes, unless the goal of the workout is to overload the cardiovascular system. By shortening the workout and recovery segments even more, you can run at even higher intensities.
How To Incorporate Interval Runs Into Your Training
It is important to start adding interval runs gradually. Some runners like to do fartlek runs, which are less structured. These can be done by running for a few minutes “hard” and a few minutes “easy” (without a specific pace).
As you move into more structured interval runs you can adjust the pace, duration of work, number of reps, and recovery intervals. Adjusting these variables will make the workouts harder or easier.
Keep in mind what your current race pace is for a given distance when planning interval runs. If you are doing your interval run at 5k pace then you will want to run a total distance of high intensity work for at least 5k. You could also run for longer than 5k or faster than your 5k pace. You could start with 6 x 800m at slightly faster than your current 5k pace, and take a 2 min recovery between intervals.
How to Plan Your Recovery Intervals
The recovery intervals are a very important part of interval workouts. In the 1930s German coach Waldemar Gerschler and physiologist Hans Reindell found that cardiovascular development occurs during the recovery portion of the workout, rather than during the high intensity portion. During the recovery intervals your heart rate declines rapidly leading to a brief increase in stroke volume as a large volume of blood is returned to your heart. During an interval workout, stroke volume increases several times (during each recovery period) which can lead to cardiovascular improvements like increased maximum stroke volume and improved capacity of your oxygen delivery system. Usually the recovery intervals should be somewhere between 100 percent and 50 percent as long as the repeat itself, but this depends on the fitness level of the runner and purpose of the workout.
Sample Interval Run Workouts To Try
Before beginning an interval run, it’s always important to start with a warm-up. This can include easy running, dynamic stretching, drills, and/or strides.
Semple Interval Workouts:
6-8 x 3 minutes at 5k race pace with 2 minute recovery jog
8-10 x 400 meters at 3k pace with 90 second recovery jog
4-6 x 60 seconds at 1 mile race pace with 2 minute recovery jog
2 x 200 m, 300 m, 400 m at 1/2 mile race pace with 2 minute recovery jog between each interval & 5 minutes rest between sets.
Remember that these are just examples of workouts. Always consider your current fitness and your goals when planning your interval runs.
Final Thoughts on Interval Runs
Interval runs can be a fun and effective way to improve fitness. They don’t always need to be done for the purpose of getting faster. They can also be used to break up a run or build back fitness after time off. The most important part of interval running is to plan them appropriately for your fitness and goals. If they are done too fast or for too many reps you can risk overtraining or injury. If they are done too slow or without enough reps you won’t reap the benefits of the workout. It’s all about finding that sweet spot that will be the most effective for your fitness.
Do you include interval runs in your training?
What is your favorite interval run workout?
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