Sadly there's a lot of really bad advice out there about gaining muscle, passed around by ignorant people who should know better, and the real tragedy is that inexperienced people follow this bad advice without question.
Any piece of advice given to you needs to be evaluated - and you need to decide if it works for you.
One that I often hear is that you should do stretching exercises at the very beginning of your workouts, before you hit the weights.
This is total rubbish and here's why; Think of your muscles as elastic bands.
You may have noticed that a cold elastic bank often snaps, whereas a warm elastic bank is much more supple.
Same thing applies to your muscles.
If you stretch a cold muscle, you're almost inviting an injury - and these types of injury can take an age to heal, especially as you get older.
We can be talking months of rehabilitation, and sometimes longer than that.
Another bodybuilding cliche that happens to be true is "If you're injured you can't train - and if you can't train you can't gain.
" So true - these injuries can really put a crimp on your muscle building efforts - all because you stretched a cold muscle.
I hope that makes the point clear to you! Please note I'm absolutely not telling you not to stretch - but stretch at the right time.
Here's the right sequence of events; First, do your warming up stuff - always warm up properly before hitting the weights, this is even more vital in the cold months, and as you get older of course.
When you're warmed up, then it should be OK to stretch - but do the stretching gradually without forcing it.
You could try say three "reps", each one being a bit more of a stretch than the last, if that makes sense.
After you've completed your workout and showered, then is a good time to stretch again, whilst you're still warm - this should help get rid of muscle soreness too.
If pushed for time, at least try and stretch the muscles you exercised in your workout.
Good luck.