The benefits of sticking to a fitness plan exceed the obvious physical benefits. Exercising can have mental health benefits as well that include improving your mood and reducing the risk of depression. Even just by finding time in your day to stay fit like taking walks or using the stairs, you can not only improve your physical health but also your mental health.
Check out this infographic by Fitness19 for more information on the relationship between fitness and mental health.
[Click here for full size version]