A gym client suggested his views about training. He spoke about his bench-press. He says that he bench presses one day in a week. Subsequently, he took a break for one week after three or four weeks of continued benching. He notes that, surprisingly, the weights shoot up whenever he takes intermittent breaks. He felt much stronger because of the rest period. He however suggested and thought, on the contrary, that more frequent workouts lead to more gains.
I suggested that the extra rest period would have led to neural adaptation. In other words, more frequent workouts can lead to neural fatigue. The central nervous system, CNS, can take much longer to recover than your muscles. This also means that your performance while training is largely decided by neural rather than muscular factors most of the time.
Moreover, a local muscular fatigue leads to muscular discomfort but muscles can and will recover in quick time. Nonetheless, consistently stressing the body reserves can lead to negative effects on hormonal status. This causes cortisol, a stress hormone, to rise, testosterone to drop. An increase in cortisol levels suggests muscle atrophy—wasting away and a suppressed testosterone leads to decreased muscle mass and strength and several other negative factors. This kind of stressing the hormones is termed neuroendocrine fatigue. Performing high intense workout day in day out can lead to this kind of fatigue. For example, we perform HIIT drills typically on Wednesdays. If I asked to execute them every day it would lead to neuroendocrine fatigue.
Last but not the least, lack of sleep and stress at work place can lead to a different kind of fatigue–environmental. However, note that longer sleep has shown in research studies that it can lead to improved performance in sports, so external forces such as lack of sleep can negatively impact the performance of the individual.
Intermittent breaks can be a blessing in disguise. Why do you think I insist on a deload week after few weeks of consistent strenuous strength training?