Many people believe that a 30-minute workout is enough to build muscle. However, this is not always the case. The amount of time that you spend working out actually plays a major role in how effective your workout will be. If you are only doing a 30-minute workout, it is likely that you will not see the same results as if you were to do a 60-minute workout. This is because the 30-minute workout does not provide enough time for your muscles to fully recover.