Hi, as per the subject i have a few running questions.

Q1. Can you add body weight and become a stronger runner? Or is light always best?
I'm nearing mid-40s (age) and for the past ten years i've always been about 147lbs to 153lbs, averaging around 150lbs. I run about a 38min 10km so not slow but not fast. Lately i've wanted to put on some weight to have started eating a lot more than usual over the past three months. I'm now between 156 and 160lbs. If i hit an average of 160 is it realistic to think i can maintain the same run pace as before? i.e. will my body get used to it and build up muscle? BTW, the urge to put on weight is wanting to look healthier and also the feeling that becoming stronger may be healthier.

Q2. Connection between piriformis and back
I have often have piriformis pain in my RIGHT hip. When running longer distances I also get a pain in my upper LEFT back (ie. beside my neck). Can any physios out there make a connection between the two and tell me what's going on? When i'm sitting down it often feels like i'm sitting on my right side more than my left.

Thanks!

C