Training

A Comparison of the Five Training Elements

Part 4:  Reduced training intensity and Review

For his final study, Hickson studied the effect a reduction in intensity had on performance.  Again following the same 10 week protocol as in the three previous studies, Hickson had the subjects exercise for 40 minutes per day, 6 days per week, for 10 weeks.  At the end of 10 weeks, the subjects reduced intensity either 1/3 or 2/3 while maintaining both frequency and duration of training.

To accomplish the reduction in intensity, the subjects cycled with a one- or two-thirds decrease in wheel resistance.  With running, subjects reduced their running pace so that they ran one- or two-thirds of the distance as performed during the final 3 weeks of the initial training period.  The subjects still trained 40 minutes per day, 6 days per week.

As in the previous study on reduced duration, during the initial 10 week training period intensity was plateaued for the final three weeks of training.  Also like the previous duration reduction study, the subjects were tested for both short- and long- term endurance performance.

Results

The results of reducing intensity were vastly different than when either frequency or duration was reduced.  Short term endurance remained the same for the 1/3 reduction group.  Short term endurance decreased significantly for the 2/3 reduction group.  Long term endurance performance decreased significantly for both the one- and two-thirds reduction group.  Long term cycling endurance decreased 21% in the 1/3 reduction group and 30% in the 2/3 reduction group - a decrease of 39 minutes in the 1/3 reduction group and 61 minutes in the 2/3 reduction group.

Table 3:  Decrease in cycling performance after 1/3 or 2/3 decrease in intensity

Discussion

At a minimum, the results of this study show that intensity is the primary training variable responsible for maintaining performance.  This has strong implications for those who support conventional training wisdom.  As noted in the introduction, conventional wisdom holds that volume of training is the most influential element of training.  As a result of this belief, runners are commonly advised to “build a base” by conducting a training phase of increasing weekly mileages conducted at easy running paces.  This study clearly shows that any runner who has increased capacity via high intensity training and who then begins a period of “base building”, or lower intensity training, can expect a immediate and profound decrease in performance due to the decrease in intensity.  A return to previous levels of capacity is likely to occur only when intensity is restored to previous levels.

There are other important lessons here, which we will cover next in a review of all of the studies.

Review

An initial analysis of the results of these four studies seems to support the idea that volume of training is more important in improving performance than in maintaining an already trained performance level.  Indeed, this may prove to be the case, though more research on this topic is needed.  However, a more detailed examination of the results of these studies supports a different view on the importance of the five elements of training.

First, recall that in the first two studies intensity was increased every week of the initial 10 week training phase.  In the last two studies intensity was plateaued during weeks 7 – 10.  Frequency, duration, volume, and specificity of training during the initial 10 week training period were constant in all four studies – only intensity was modified.  The magnitude of improvements in the last two studies was significantly less than in the first two studies.  Since intensity was the only variable that was modified and performance changed in conjunction with these modifications, this demonstrates that intensity is responsible for the changes in performance.

The observation about the role of intensity in improving performance during the initial 10 week training period was addressed only once by the researchers.  They noted in the reduced duration study that performance improvements were not as great as in the previous two studies.  They offered two possible explanations.  One was that there might be some unidentified physical limitation in the subjects or second, that perhaps the lower level of intensity had negatively impacted performance improvements.  For unknown reasons the researchers did not address this same phenomenon when it occurred in study four.  In any case, since the identical initial training protocol was used in both the third and fourth studies, with the same results of decreased improvements, it clearly indicates that intensity was the reason for the lesser performance.

The second significant observation from these studies is that, with only one exception, each plateau of intensity was followed by a plateau in performance.  (The only exception was the decreased long term endurance of the group that decreased training duration to 13-minutes per day and this can be logically explained by the significant decrease in specificity of training.)  Other than the one observation about plateaued performance noted above, the researchers did not address the observation that plateaus in intensity were followed by plateaus in performance.

The third significant observation is that even a small 1/3 decrease in intensity was enough to significantly affect performance.  (Consider that a 1/3 decrease in intensity would result in a runner who is capable of training at a 6-minutes per mile pace training at an 8-minute per mile pace.)

Below is a comparison of the observations about volume and intensity observed during these four studies.

Compare these results:

To these results:

As our summary above illustrates, volume of training did not play a significant factor in changes in performance in any of the four studies, while every change in intensity resulted in a performance change.

The researchers identified that intensity played a primary role in maintaining performance.  Since they did not identify that intensity plays a dominant role in improving performance, nor did they identify that each intensity plateau resulted in a performance plateau, it is understandable as to why they reached the conclusion that a higher volume of training is required to improve performance than is required to maintain it.

However, when we combine the observation that intensity played a key role in both improving and maintaining performance and volume exerted little to no influence on performance, we can logically draw the conclusion that intensity, and not volume, exerts the most influence on both improving and maintaining performance.

 Reference: 

1.  Hickson, R., Bomze, H., Holloszy, J.: Linear increase in aerobic power induced by a strenuous program of endurance exercise:  J. Appl. Phsiol., 1977, 42(3), 372-376

2.  Hickson, R., Rosenkoetter, M.: Reduced training frequencies and maintenance of increased aerobic power:  Med. Sci. Sports Exercise, 1981, 13(1), 13-16

3.  Hickson, R., Kanakis, C., Davis, R., Moore, A., Rich, S.: Reduced training duration effects on aerobic power, endurance, and cardiac growth: J. Appl. Physiol., 1982, 53(1), 225-229

4.  Hickson, R., Foster, C., Pollock, M., Galassi, T., Rich, C.: Reduced training intensities and loss of aerobic power, endurance, and cardiac growth:  J. Appl. Phsiol., 1985, 58(2), 492-499

5.       Houmard JA, Scott BK, Justice CL, Chenier TC.:  The effects of taper on performance in distance runners. Med Sci Sports Exerc. 1994 May;26(5):624-31