Time length of a workout

A workout should only last as long as you want it to. The best way to answer this question is to see how many reps you do first. You should do about 12 to 25 set of reps per each workout. This means that for every workout set of reps you do, It should be added to your total and fall into about 12 to 25 reps for the best results of your workout. This however, does not include your warm-ups or stretches at the end. If you take less breaks in between each set of reps, it will be a shorter workout, but if you take a more length bread, it will last longer. This is the best way that your workout should be ran for the most muscle growth. Make sure that you give a break day after each workout with that muscle group, for it can verstress you muscles and lead to injury.