Are You Performing Your Intervals Correctly?

There is a ton of research in the last few years that has lead everyone to believe that intervals are the cure of everything.  They definitely should be a regular part of your training.  The hormonal response and gene expression that comes from intense efforts for short periods of time have proven that they have a roll for all clients.  The problem in fitness is that the industry takes a small amount of science and markets it to create programs that are just shorter, but not necessarily better. 

Many programs claim that only doing intervals is all you need for long duration cardio events.  This is not true although some of what you read would lead you to believe that intervals will solve all the problems of any fitness program. 

Intervals can definitely improve a cardio competitor’s maximum sustained power but the longer duration energy system still needs to be taxed on a regular basis and properly developed.  However, in tandem one could achieve improved results.  

The other problem with many interval training sessions is that they are no longer intervals but just harder than normal cardio for short periods.  This is because of inadequate output levels and poorly timed rest between intervals.  We are in a fitness world where harder is always considered better.  This is so wrong!   As you get fitter you need to increase intensity, but you have to build in greater rest in order to increase intensity.  If done correctly 6 to 10, 30 second intervals completed in a half hour can be brutal.  However, many would look at this as too short of a workout.  This is because they are not measuring the output to make sure there is an overload in the efforts.  5 min of total work time can be one of the hardest workouts of the week. 

Our FUBAR VersaClimber workouts have utilized the science behind intervals very effectively and the VersaClimber as a machine is perfect for these types of overloads. 

When starting interval training spend time on developing baselines so that you know what type of output you are capable of in a maximum effort.  These baselines are dynamic, so as you get fitter they change.  Pay attention to these changes and make adjustments.   If you want the most sophisticated measure you may find lactate testing and VO2 max testing helpful in determining these baselines.  I find that power is the easier and most effective way to measure output.  You spend time identifying power outputs at different levels of intensity.    You have to have a good understanding of your capabilities before you can determine the interval time and intensity.   

This leads me to one of the most important parts of utilizing intervals.  Measurement of output!  Typically this is where the wheels come off the workout.  You must measure the amount of output!   If you do not, then the intensity of an interval late in a workout will diminish in output to such a point that there is little value.  I call this no man’s land.  It is not hard enough for overload, but leads to overtraining and valueless fatigue.  Without measuring output you cannot determine if the time of the interval and rest period is adequate.   Utilize power as your primary measurement tool.  This eliminates most other issues that may be impacting performance.  In our Fubar classes we put output on the board and look at pacing to help the client determine appropriate outputs based on their fitness level. 

How do you measure output of an interval?  Time and distance is the poor athlete’s power meter.  For example you are doing sprint intervals for 20 seconds on the track.  You want to measure the distance you are covering during these intervals. This will tell you whether you are producing more power than the previous interval.  On the VersaClimber we look at time and distance.  If in a 30 sec interval the total feet increases more power needed to be produced if all else is equal.   On a slide board we use number of touches in the time of the interval and record it.  More touches mean more power produced and now you have a way to measure improvement.  It also allows us as coaches to determine if the interval should be shorter/longer, or should there be more rest between the intervals and also how many total intervals to perform.

The quality of the interval is of great importance. Poor output in your interval sessions will just make you fatigued with little performance value.  This can lead to the start of overtraining.  This is typically the problem with poorly coached group cardio workouts.   Intervals are also an excellent window into your fitness.  If you have in the past been performing much greater power outputs than the interval currently being performed then maybe you have not had enough rest since your last workout.  If we observe this lack of output we would skip these intervals and pick them up again after the athlete has had adequate rest to perform at the desired output.  The interval is a great barometer of how rested you are and the speed of your regeneration and health.

If you are going to perform intervals in your training one of the first things you need to think about is determining your baselines and then coming up with a method for recording the output on an ongoing basis.  This will allow you to see what type of training outside of your intervals is adding or subtracting from your performance in an interval and also what type of intervals are adding to your performance outside of the intervals.


Jacques DeVore, CSCS