Training

Frequency vs. Intensity vs. Duration vs. Specificity vs. Volume

A Comparison of the Five Training Elements 

Part 1 - Introduction

 Physiologists have traditionally identified four primary elements that comprise any workout - frequency, intensity, duration, and mode.   

If we limit our discussion to just one mode, or type, of exercise (in this case, running) then we have three elements, or variables, remaining that can be manipulated in order to achieve our desired workout result.  It is the combination of frequency, duration, and intensity that determine the training effect we will experience from any particular workout. 

Though we can describe any particular workout with these three traditional variables, we need to add two additional variables in order to more completely describe a training program. The two additional variables that must be considered when discussing or designing a training program are volume and specificity.  The combination of frequency and duration determine the overall volume of our training program, while the combination of duration and intensity generally determine the specificity of a training session or training program.  Note that for running, mileage is frequently used as a measure of training volume. 

The combination of all five elements - frequency, duration, intensity, volume, and specificity - determines the overall effectiveness of our training program (again, we are limiting our discussion to just one mode of training – running).  However, while all five variables play a role in determining performance that is not to say that they all exert the same level of influence on performance.  Each variable could influence performance to a different degree.  For example, volume of training might exert the most influence on performance while intensity exerts the least amount of influence on performance.  All five elements are necessary, but may not be equal.

Conventional training wisdom suggests that volume of training is the most important element in determining performance.  Again, this is not to say that the other variables of frequency, duration, intensity, and specificity are not important or don’t play a role in performance.  Instead, conventional wisdom suggests that the influence of any of the other four variables is less than the influence exerted by overall training volume.  The result of this belief is that it is commonly recommended to runners that in order to maximize performance the first element to address is increasing overall training volume, with an ultimate goal of running as many as 100 miles per week.

While conventional wisdom suggests that volume plays the most dominant role, I and others point to one or more of the other variables as exerting the most influence on maximizing performance.  So, disagreement exists as to the level of influence any of the five elements has on performance.

The level of influence any variable has on performance is an important topic because accurately determining the influence of each variable will allow us to develop the most effective training program.  Incorrectly identifying the relative influence of any or all of these five variables would likely result in a less effective program, an ineffective program or worst of all, an injury-producing training program.

To date we have mostly relied on conventional wisdom, which, in turn, is based heavily on anecdotal evidence, to determine the relative contribution of each of these variables.  Is there any way to verify the accuracy of conventional wisdom?  Yes there is.  As always, some well designed research would do the trick.  What does research have to say about the influence of each of these variables?  That’s what we are going to examine today.

Dr. Robert Hickson

This very topic was examined in a series of four research studies conducted by Dr. Robert Hickson and colleagues at the University of Illinois (1-4).  Through these four studies Dr. Hickson had groups of subjects exercise 40 minutes per day, 6-days per week, for 10 weeks, all following the same exercise program.  At the end of 10 weeks of training, Dr. Hickson individually investigated 1/3 and 2/3 decreases in frequency, duration, and intensity.  By changing just one variable at a time it would clearly indicate how much effect each variable has on performance.  In this way, the researchers hoped to identify how important the variables of frequency, duration, and intensity were individually in terms of improving and maintaining performance.

To begin, Hickson had all the subjects in each of the four research studies exercise following the same protocol – 40 minutes per day, 6 days per week, for 10 weeks.  The exercise program consisted of 3 days per week of cycling on an ergometer and 3 days per week of running.  The cycling workout consisted of six 5-minute intervals at a resistance that caused each subject to attain VO2max during the 5-min period.  Each 5-min interval was separated by two minute rest intervals, during which the subjects pedaled against a resistance that required 50-60% of VO2max.  As their fitness improved, the exercise rate on the bicycle was increased from week to week as needed so that the subjects continued to work at the same high intensity.  The running workouts consisted of continuous running as fast as possible for 30 minutes per workout during the first week, 35 minutes per workout during the second week, and 40 minutes per workout thereafter, with the goal of running further each training period.  Heart rate was taken at the end of each running session and was typically at or near maximum.

To sum up, the subjects cycled 3 days and ran 3 days each week, at intensity levels that were high and kept approximately constant for the duration of the programs (i.e. resistance was increased to account for improvements in capacity).  Performance of the subjects improved consistently over the entire course of the 10 week training program and showed no signs of leveling off.

Once the results of the initial 10 week training period were measured, the research team was then ready to begin their examination of the different training variables.

Part 2 - Reduced Training Frequency