Three Effective Ways for Runners to Monitor Interval Intensity
If you are an everyday runner hoping to improve your performance for your target event, you need to do some speed work - or intervals.
Intervals, or kicking up your intensity for short periods, build speed, endurance, efficiency of movement, as well as bring a host of additional physiological benefits.
But how hard should you run?
While heart rate monitors and wrist devices are great tools to know how hard to go, what’s the best way to determine intensity if you aren’t using those?
Or, what can you do if you want some additional feedback or assurance that the devices are working right?
Three ways to monitor interval intensity without a device include the Talk Test, Fast or Fastest Speeds, or RPE (Rate of Perceived Exertion).
Let’s take a step back, first, and talk generally about intervals.
Targeting training by targeting energy systems
To understand how best to target our training, it helps if we understand how our bodies utilize energy.
Think of the energy systems as a rocket bound for Mars.
The first section (ATP-CP) gets the rocket off the ground quickly and forcefully but lasts only a few seconds.
The second stage (mostly anaerobic) provides a slightly longer boost to get into space, and the third (mostly aerobic) keeps the space capsule going where it’s going.
So we need to target three distinct energy systems in our training.
The only problem with this rocket analogy is that you use some of all systems while doing your endurance sport.
All three work as a continuum, providing different amounts and sources of energy depending on the activity.
Three energy systems work together to fuel your endurance adventure
The main idea of training is to stress the three systems so that they work better and you improve your performance.
The “moderate” zone is mostly aerobic. This is where most of your training takes place.
Your heart rate and effort are moderate and you do long, slow efforts.
The “heavy” zone is mostly anaerobic, which means it requires carbohydrates to fuel the work. “Heavy” zone intervals are tough. You have to hold a pretty high intensity for many minutes. They boost the capacity of your heart to work and more efficiently utilize oxygen, fat, and glucose as fuel sources, among other benefits.
The final zone is “severe,” which is essentially maximum effort. These intervals last usually 60 seconds to five minutes.
Heart rate monitors can help you monitor intensity
Runners can monitor the intensity of their intervals by using a heart rate monitor to track their heart rate during exercise.
Research has shown that monitoring heart rate during interval training can help runners accurately gauge their level of exertion and adjust their intensity accordingly.
According to a study published in the International Journal of Sports Medicine, heart rate monitoring can help runners achieve more effective interval training by keeping their heart rate within their target zone.
The study found that runners who used heart rate monitors during interval training were able to maintain a higher average heart rate than those who did not use monitors.
Another study published in the Journal of Strength and Conditioning Research showed that heart rate monitoring during interval training can help runners improve their aerobic capacity and endurance.
The study found that runners who used heart rate monitors during interval training were able to increase their VO2 max, a measure of aerobic fitness, by over 10%.
For example, you can program devices so you can follow a specific workout or beep when you’re in the right heart rate zone.
Heart rate can lag for short intervals
But your heart rate lags when you're doing short intervals.
You don’t often get into the right training zone until up to a minute into the intervals, and these hard intervals are often only 30 to 90 seconds long!
Plus, our bodies change daily, and our training “zones” might not be perfectly set up.
Fatigue, sleep, and caffeine can all affect your heart rate as well.
Pace is another metric
Runners can use pace or a percentage of threshold pace as a tool to monitor interval intensity.
Runners often use targeted pace to reach a goal, for example, 5k race pace.
But you still have to keep looking at your watch to know exactly what your pace is.
While there are pace guides available, it is a challenge to understand how fast to run to be consistent throughout the interval.
If you’re a runner, you can go to a local track and time yourself per lap.
But the next three tools can be effective tools for understanding how your body responds to the work you’re asking it to do.
The “Talk Test” is one way to know the interval intensity
The Talk Test is a valid way for runners to monitor the intensity of their intervals. Research has shown that the Talk Test is a reliable and practical tool for measuring exercise intensity during both moderate- and vigorous-intensity activities, including interval training.
A study published in the Journal of Sports Science and Medicine found that the Talk Test was a valid way to monitor exercise intensity during high-intensity interval training (HIIT). The study compared the Talk Test to other objective measures of exercise intensity, including heart rate and blood lactate levels, and found that the Talk Test was just as accurate in determining the intensity of exercise.
Another study published in the International Journal of Sports Physiology and Performance found that the Talk Test was a reliable way to monitor exercise intensity during moderate-intensity treadmill running. The study found that the Talk Test was just as reliable as heart rate monitoring in detecting changes in exercise intensity.
Overall, the Talk Test is a simple and effective way for runners to monitor the intensity of their intervals, particularly during high-intensity workouts like HIIT. By paying attention to their ability to talk or sing during exercise, runners can ensure they are working at an appropriate intensity level and making progress towards their fitness goals.
In the “moderate” intensity zone, you are able to have a normal conversation, but you can’t fully discuss religion or politics because you can’t get enough air for that.
You can sing but not the full chorus of Handel’s Hallelujah!
In the “heavy” intensity zone, you can talk, but not in complete sentences. Shorter efforts mean less ability to talk, longer efforts mean slightly more.
In the “severe” zone, you can say individual words but only in an emergency, like “help.”
You are, however, able to curse your coach in colorful language.
The Talk Test, like all measures of interval intensity, takes some time to learn how your body reacts.
Plus, I often train alone, and singing often brings funny looks!
Rate of Perceived Exertion (RPE) is another way to monitor interval intensity
In addition to heart rate monitoring, runners can also monitor the intensity of their intervals using the rating of perceived exertion (RPE) scale.
The RPE scale is a subjective measure of how hard an individual feels they are working during exercise, typically rated on a scale from 1-10.
According to research published in the Journal of Strength and Conditioning Research, the RPE scale is a valid and reliable method for monitoring exercise intensity during high-intensity interval training.
The study found that participants who used the RPE scale to monitor intensity during interval training were able to accurately self-regulate their intensity based on their perceived level of exertion.
Another study published in the European Journal of Applied Physiology showed that combining heart rate monitoring with the RPE scale can further enhance the accuracy of intensity monitoring during interval training.
The study found that when heart rate monitoring was combined with the RPE scale, participants were better able to maintain their target intensity zone and achieve greater improvements in cardiovascular fitness.
Overall, using the RPE scale in combination with heart rate monitoring can provide runners with a more comprehensive and accurate picture of their exercise intensity during interval training.
A One is getting off the couch to get another cup of coffee; Ten is a “I think I’m going to die” effort.
Typically, a “moderate” effort is about a five. It’s hard, but you can do the effort for long periods of time.
Targeting your aerobic capacity in the “heavy” zone can be between 6 and 8, and maximum “severe” efforts are 9 or 10.
The challenge with RPE, though, is that how you feel is entirely subjective.
If you aren’t used to pushing yourself, for example, a seven might feel like a 10.
“Fast” or “fastest” is a third way to monitor interval intensity
In this method to monitor interval intensity, you have two speeds to do most intervals: fast and fastest.
Pick a speed that will allow you to stay in the “heavy” zone for as long as your target interval length.
“Fast” days are for building aerobic capacity in the heavy zone. “Fastest” days are for maximum efforts in the severe zone.
What’s key is that you keep intensity consistent for the whole interval.
You should try the same pace, but as you get more tired, the same pace will increase the intensity.
The end of the interval will feel really really challenging to keep up the intensity.
And that’s what makes the intervals so challenging: You’re working hard, breathing heavy, and you still have minutes to go!
Want to know more about what you can achieve?
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Do you have questions? Email me at paulw at SimpleEnduranceCoaching.com
I support a limited number of cyclists and runners achieve their goals with more strength, endurance, and mobility.
Contact me or sign up for Virtual Coffee so we can discuss your goals, ask questions, and talk about making your endurance training more effective, fun, and Simple.
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Paul Warloski is a:
- USA Cycling Level 3 Coach
- RRCA Running Coach
- Training Peaks Level 2 Coach
- RYT-200 Yoga Instructor
- Certified Personal Trainer
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