… because it´s that important!
In short; if you dont value you sleep as much (or more!) as you value your diet- and exercise scheme, it´s likely you´re a bit retarded.
Below are quotes taken from BodyInMind that sums up the intimate connection between exercise, sleep and pain. Read them, think for a minute or two, and go to bed to consolidate.
Sleep is an essential biological phenomenon, and sleep deprivation causes various physiologic and behavioral changes in the body. It has been shown that total sleep deprivation (Shuch-Hofer et al., 2013) or sleep deprivation of a specific stage of sleep (Roehrs et a., 2006; Azevedo et al., 2011) cause hyperalgesia (exaggerated sensitivity to pain). In addition, people who sleep less than 6 hours or more than 9 hours seem to have increased frequency of self-reported pain (Edwards et al., 2008). The sleep-wake cycle and the pain modulation system share regulating neurobiological systems (Foo and Mason, 2003), which may help to explain the relationship between sleep and pain.
There is subjective and objective evidence (through questionnaires about sleep, and polysomnography and actigraphy, respectively) that physical exercise is able to improve sleep patterns in healthy individuals (Keedlow et al., 2015). Particularly in insomnia patients, regular exercise leads to benefits over time, being comparable to pharmacotherapy and behavior therapy (see review Keedlow et al., 2015). Pilates, for example, improves muscle flexibility and strength and also improves life quality and has been shown to be able to improve sleep quality (Caldwell et al., 2009 and 2010; Leopoldino et al, 2013).