In relaxing your body, your muscles become less tense as well. Having to wake up after a good sleep and getting ready for the day can already be a lot of physical stimulation. Then there’s going to school or work, or cleaning the house and taking care of the kids. With so much stuff to do, your muscles slowly but surely get all tensed up. With each and every task you undertake, you make use of your muscles to achieve them, and this, in turn, tightens them up and leaves you exhausted.