The rest days that you take each week are just as important for increased size and strength as the workout routines that you use on the other days. There are a number of reasons why you should take 1-2 days off each week and forgo the workout regimen on these rest breaks. They will help you recover fully, make your training more effective, and help minimize any soreness that you experience. Rest days will help you avoid overtraining while increasing the size and definition of your muscles, and these short breaks can also improve immune function and improve your body’s defenses. A day of rest also helps maintain balance in your life and allows time for other important things as well. Some get so caught up in bodybuilding that they make it their entire life and it consumes every waking moment and thought, leaving no time for family or friends.

Recover Fully and Avoid Overtaining

A workout makes small tears in the muscle tissue, and when these tears heal, this increases the size and strength of the muscle affected. This is how you bulk up. What happens if these small rips are not allowed to heal properly though? Failing to include a rest day or two in your training schedule each week will mean no recovery period so that any damage can be completely reversed. Overtraining is a problem that many bodybuilders and weightlifters experience. If you train too hard and you never allow the muscle tissues to repair and recover fully then the best possible growth and results will not be experienced. In this situation you may actually decrease the mass that you gain instead.

More Effective

Allowing 1-2 rest days will help you start again rested and recovered, and this can make a workout much more effective. Muscles will be primed and ready to go, and workouts will be more intense and will often last longer. When the session starts off with damaged or tired muscles, your efforts may be cut short or you may not give the workout everything you have, and this will decrease the effectiveness. Hitting the gym means getting serious about bulking up and this means making your training as effective as possible. This allows you to get more from your efforts and see faster results, which typically provides further motivation to train even harder. If you do not include at least 1 day of rest each week you may end up burnt out and give up the training.

Minimize Soreness

Soreness is a problem that plagues every serious lifter or athlete at one point. This may be caused by muscles that are not fully recovered and are still involved in the repair process. When you are sore the effort put into a workout may be lower, and this means that the results will not be as good either. Another problem is that the muscle tissues which are still injured may be damaged further, leading to a condition that prevents further training efforts.

Increase Muscle Size and Definition

The goal of any workout that involves weight training is to increase the size, definition, and visibility of the muscles. When these tissues are allowed to repair completely before they are ripped again by the next workout session then bigger muscle size, better definition and visibility will be achieved. When muscles are torn and exhausted then they will not gain as much in size or strength, no matter how often you workout or how much you lift each session. When a proper diet is followed and 1-2 rest days are included in the training schedule then better gains will be seen in a shorter period.

Boost Immune System

Stress, injuries, and exhaustion can all impact the immune system. Taking a day or two off during each week of strength training and weightlifting will help boost the immune system and strengthen the defenses of your body. Overtraining or not allowing sufficient rest periods on a weekly basis will drag down the immune system and make you more susceptible to every illness or bug that comes along.

Maintain Balance

Bodybuilding is a great goal but it is also important to maintain some balance in life as well. Spending all of your time in the gym without fail and not adding in any rest days is a common mistake. Everyone needs time for other priorities as well, such as family, romantic relationships, and even work. Life should be well balanced with time scheduled for training as well as time set aside for other priorities.

Working hard to gain mass and size is required if you want to pump up and get the desired results, but rest days are also crucial if you want to see great results and maximize from the training efforts put in. Continuous workouts and a schedule without any rest days will weaken muscles rather than improving these tissues and building the mass you want.

Source

http://www.aworkoutroutine.com/deloading-and-taking-time-off/

http://training.fitness.com/weight-training/rest-days-do-you-take-them-after-weight-training-27266.html