Stress and Anxiety on a chronic level can be detrimental to your health. Not only can it reduce your immune system response but can inhibit your muscle gain. High levels of the stress hormone cortisol will compete with your testosterone to attach to your receptors. As well high cortisol levels can increase inflammation and reduce your white blood cell count used to combat infections. Anxiety and worry can also prevent you from getting optimal sleep with sleep deprivation causing lower growth hormone release and impair immune system function.