"Steroid" is the name given to a chemical compound with a specific structure. In everyday speech, the term steroid is applied to several medications that share this structure; however, these medications have very different uses. Anabolic steroids are a class of drug that mimic the effects of male sex hormones called androgens which stimulate muscle growth and secondary male sex characteristics. They are often abused by bodybuilders and other athletes to build muscle mass and so should be used with caution. When prescribed, oral steroids should be taken as directed. If you come across extra pills that haven't been taken, and are unsure if they are steroids, you can identify the pill based on its physical appearance, information on the bottle, or by consulting a professional.
While we can all agree that running is one of the most physically enduring and best methods for attain perfect physical fitness, there is something you should be doing in between all of that running to ensure that your body stays in peak shape and that is to take the proper amounts of rest. The usual recommendation is to rest one day in between runs, so essentially you are doing a day of running that is followed by a day of resting. There are other workout plans as well that involve running with different kinds of rest periods, so what you just read is a basic example of how to rest your body while going through a running routine.