Simply to better prevent accomodation. I honestly have no scientific datas to support it, I’m going from experience with the athletes I’m training.
This is from the upcoming article:
A STABLE TRAINING LOAD LEADS TO BOREDOM AND MONOTONY
Boredom and monotony are often seen as the same thing. In training they are not exactly the same.
Boredom is when something no longer gets you excited, this obviously affects motivation.
Monotony is when the overall training stress of the session stays the same for long enough for that stimulus to no longer lead to adaptations/changes in performance. If you impose a stress on your body, it will adapt and get stronger. But if you keep imposing the same type of load over and over, eventually the body stops adapting (even if you try to add weight over time).
In both cases, lack of variation is one of the main underlying cause.
And by lack of variation I don’t simply mean changing the exercises or methods. It can simply be a matter of always using a similar training volume or level of effort.
At first, changing the exercise while keeping volume and effort the same will be enough to prevent monotony and boredom. But fairly quickly it’s not enough. That’s why you need to have frequent variations in the training load to allow the body to keep adapting.
And that doesn’t even mean constantly increasing the training load. See, periods of lower stress training make the body more responsive to the bouts of higher training demands. In fact, the greater the contrast is between the high and lower demand periods, the higher and more sustained the progression is.
That might be the real benefit of a deload week: not necessarily the recovery but making the subsequent higher demands periods more effective by decreasing training monotony.
An article by Carl Foster (“Monitoring Training in Athletes with Reference to Overtraining Syndrome” in Medicine & Science in Sports & Exercise, July 1988). Found that the more similar the high and low load periods were, the less progress was made.
That’s the main reason why I like to throw in a bodybuilding week after three weeks of performance work. Both are essentially the opposite and that huge contrast makes the body more receptive to both phases and greater adaptations and gains follow.
This is a concept that I’ve been using for close to twenty years and I even wrote about it in the past here on T-nation (https://www.t-nation.com/training/program-shock-do-the-opposite ). At the time I didn’t fully understand the workings behind the strategy, but it’s something that I was doing with a lot of success.
Also, from a mental standpoint, the drastic shift in focus and mindset from one period to the next will have a dramatic impact on keeping your motivation and interest high, which will have a significant impact on the quality of your training.
Not to mention that it gives you a mental relief from always having to try to beat the logbook and use more weight.