Over the past 6-12 months or so I've been weight training 2-3 times per week and have built up a fair amount of muscle (even if I do say so myself!).

However since the new year I've gone on a mission to cut fat. So far so good, 9lbs down with no noticable loss in muscle so I figured I'm doing the right things. I weight train 2 times per week with a mixture of compound and isolation movements and mix things up every few sessions to keep my work outs fresh.

I've also been doing some pretty heavy cardio at the gym and my fitness has really improved and I'm really happy with the way things are going.

The only downside is that I've had a persistant shoulder injury for the last few months. In my bid to keep my workouts going I've trained a few times on it when I perhaps shouldn't have and as a result it flares up every now and then.

Yesterday it flared up badly, probably responding to my weekend weights session and a couple of nights where I've fallen asleep on the sofa with bad posture. As a result I don't think I'm going to be able to train for a week or so and I'd really like to lay off the weights for a while to avoid aggravating it further and let it fully heal before starting again.

Now, my questions are as follows:

How long can I lay off the weights before I start to lose muscle mass? Bear in mind that I'll probably do some extra cardio and general training sessions to make up the shortfall in my regime. Will the extra cardio burn off muscle?

Secondly, Is there anything I can do to minimise the impact of this? In terms of specific excercises, diet and general tips?

FWIW I will be visiting the doctor about my shoulder on Thursday. I think it might be the Rotator Cuff.