Interval Training for Cardiovascular Fitness. Part II: Planning your interval program

Four things to think about when planning your interval training:

1. Keep it simple

Even if 15s work 15s recovery would be the best method, this type of workout may be difficult to execute. This is especially true if you are training by yourself or running on roads versus the track. The most important thing to consider in your training regimen is that is has to be something that you can actually do. Your training environment and schedule are all things that need to be considered. For example, if you are training in the dark how often do you want to look at your stopwatch? If you are training on the road, how ridiculous do you want to look stopping and starting every 15 seconds? What can you do if you get to the track ans realize you forgot your watch? (…or does that only happen to me?)

2. Remember that this is an aerobic workout

The goals is to increase the amount of time you spend processing the maximum amount of oxygen you are capable of without increasing lactic acid. If you feel sore during or the day after your training, this indicates that you accumulated too much lactic acid. Adjust by doing fewer intervals, decreasing your intensity, or increasing the length of the recovery times.

3. Form

I firmly advise running only at speeds and volumes in which you can maintain good form. By good form, I mean that you should be landing on the midfoot or forefoot, and you are able to remain tall in your core. Both speed and fatigue will affect your form.

If you experiment with running at different speeds, you will notice that your form subtly changes. Sprinting, you will naturally be contacting the ground with the balls of your feet. As speed is decreased, the point of contact with the ground tends to shift farther back on the foot. Some people even strike the ground with their heels at a slow jog. The amount of time your foot spends on the ground should be minimized. Think of each step as its own plyometric event. The foot should tap the ground, not stick to it.

The second contributor to form is level of fatigue. If at any point there is flailing of the arms, or slouching in the trunk, I will stop running. Every repetition done with poor form is practicing a motor pattern you don’t want to learn. Running with poor form also invites overuse injuries.

Pick intervals at which you can fun fast enough to maintain good form. Stop your interval training session if your form starts to break down.

4. Rest intervals

Deciding on the intensity/time/duration of work intervals is only part of an interval workout. The next thing to decide is the intensity and duration of the rest intervals. Studies show that complete rest does not clear lactic acid from the bloodstream as well as active rest intervals. Some people prefer jogging intervals. I recommend walking intervals for two reasons.

First there is the form issue. Jogging usually results in lollygagging accompanied by plodding or shuffling feet. I cannot think of a less efficient, more awkward form of movement. Please stop! Jogging in the way I’ve described also uses a very small range of motion in the hip. Walking is actually more similar to sprinting than jogging in hip range of motion. This is why so many long distance runners experience tight hamstrings and hip mobility issues. Walking can help prevent this tightening up because the range of motion in the hip is larger.

Second, some studies show that clearance of lactic acid between bouts of work is more efficient at 40% velocity VO2 max versus 60% velocity VO2 max. I don’t know about you, but my velocity at VO2 max is slow enough that 40% , or maybe even 60% of that pace is better accomplished at a walk than a jog.

Until next time…

I hope these suggestions were helpful. In Part III of this series, I’ll give you examples of interval workouts I’ve used with a lot of success. I’m still experimenting with my interval workouts so I’ll also talk about how I’m modifying my workouts based on my prior training.

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By the way, my knowledge of interval training comes mostly from reading a studies by Veronique Billat.

Her comprehensive review of aerobic interval training research is a fantastic read.

Related Posts:

Interval Training for Cardiovascular Fitness. Part I: What is it? Why do it?

Interval Training for Cardiovascular Fitness. Part III: Three interval protocols I’ve used successfully

9 comments to Interval Training for Cardiovascular Fitness. Part II: Planning your interval program

  • Casey

    “If you feel sore during or the day after your training, this indicates that you accumulated too much lactic acid. Adjust by doing fewer intervals, decreasing your intensity, or increasing the length of the recovery times.”

    I am going to disagree with you here.

    • Casey, do you want to expound upon that? Or tell me upon what are you basing your disagreement? The aim of these types of intervals is to target primarily the aerobic system. Especially if you are doing this type of training every day, you’ll get the most adaptation if you don’t accumulate fatigue or soreness. Or are you disagreeing that the cause of the soreness is lactic acid? If so, that’s a reasonable disagreement. Perhaps I’ve oversimplified.

      • Casey

        I guess, at this point, I’m just wondering what you are trying to accomplish with these intervals.

        If I’m reading correctly, you are advocating running less, running slower, and increasing recovery. And then for that recovery you recommend walking.

        On the field, I want to be able to run faster for longer, to be able to recover quicker and, if possible, recover while still jogging. So that’s what I practice.

        The next day I’m sore. So for recovery, I go for a nice long ‘aerobic’ run.

        • Perhaps you’re misunderstanding the speeds at which the intervals are done? One of my favorite interval workouts last year was doing 20 second intervals at about 80% of my max sprint speed followed by 40 seconds of walking. If I do that 20 times two days in a row, I’ve done 40 near sprints, accelerations, decelerations, and recoveries without doing any long, slow running. I may or may not achieve that volume with one day of high intensity and one day of low intensity exercise as you’re describing. I am not saying what you’re describing is a bad idea. It’s just different. You are still allowing for recovery from an intense workout, which is good. The workouts I am describing do not need a day of recovery. You’re probably more familiar with high intensity intervals with shorter recovery periods. I believe they’re used a lot in crossfit programs and some people call it HIT (high intensity training). There is a place for those types of intervals, but that’s not what this particular post is talking about.

  • the whole point of interval training is anaerobic training. aerobic interval training does not exist.

    also, anaerobic training increases both aerobic and anaerobic performance, while aerobic training (log slow runs) only trains aerobic performance.

  • […] To understand the purpose of aerobic interval training and my opinions on it (like seriously, why is this chick walking all the time?) please see Part I: What is it?  Why do it? and Part II: Planning your Interval Program. […]

  • […] Interval Training: tips on planning your intervals | Melissa's … […]

  • Superb post.Never knew this, appreciate it for letting me know.

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