I am trying to increase muscle mass.
I completed my first month and a half of training.
Is it okay to take a one week break and come back the week after?
Will it affect my performance?
Physically, and as long as you don't starve during your break, the negative effects will be negligible.
Mentally, I can't tell you the amount of people I know who took a short break after just a little while going to the gym and never came back.
High level Olympic weight lifters suffer a ~10% loss in strength after a month of not training.
Anecdotally, I'll take a week off every couple of months (by choice or chance), and if anything I get a bit more flexible and can get back into the weight room with less nagging inflammation.
On the one week side, and definitely if you're out near two weeks or more, you might go through DOMS again.
A couple of points I'd raise:
For a lot of folks one week can turn into two which becomes five. There's a lot to be said for keeping a habit a habit. If you're traveling, consider going for a run those days or just doing something that keeps you in the mindset of training, especially if you're new to maintaining a fitness schedule.
Keep your ego in check on your first day (or few days) back, and lift at ~80% of what you did before. Lots of warmup, nice and easy. Don't get competitive with yourself or some other dude in the gym that you know you can outlift.
So provided it really is a week or two, and you ramp back in, it's really not a problem at all. If you find yourself training solidly for months, a week off can be a terrific thing mentally, to remind you what it feels like to be in shape but not constantly recovering, and physically to reset your hormones a bit and let some things heal up.
Absolutely! There's nothing wrong with taking a break from training, especially after working so hard. Besides, it's not like you'd listen to us if we tell you not to take a break :)..
If you feel you need the rest, take a break.
One week break will have little impact on your performance, provided you've been working really hard during your training AND you just don't sit down on the couch for a whole week.
Don't take a break; instead, reduce your intensity or follow a less intense program.. This is because you're still a newbie in training and it's too early to take a vacation. You might not come back!
You've started a good thing; don't ruin it with a long break; instead, you can perform some bodyweight exercises or cardio. The idea is to make training a natural part of your life; when you reach that stage, you can take as much vacation as possible because you'll always be back.
Here's a motivational site you should check out everyday while on break. Check out the profiles everyday and you'll always find the enthusiasm and encouragement to come back.
Good luck!
Yes, it is perfectly okay to take a break, as long as it is just one week and your diet and sleeping are still being kept under control reasonably. My rule of thumb is that every two months you can have a one week break. It gives your mind a chance to calm and ease and your body a chance at a long, but not too long, rest. So sure, go ahead. You won't lose strength unless you are our for more than 3-4 weeks.