Going to the gym every week with absolutely no idea about what you are going to do is a big waste of time. You’re more likely to have a less productive workout. Think about the workout plan before you get there. The best-case scenario is having a long-term workout schedule already planned that will best serve your level of fitness.
One way to prevent not having a plan is to hire a Personal Trainer. You will never have to waste time thinking about your workout or worry about wasting time doing the wrong kind of exercises. The job of a Personal Trainer is to guide you through a progressive workout programme that strengthens your weaknesses and leads you to your fitness goals.