Sailors are famous for getting tight on rum, fighting, and getting damaged. Knit a tight gansey or two (for each of your 6 sons) and your wrists and forearms are going to be sore. If you start knitting too fast you can do real damage to your body. Save your wrists for other things.
Think of knitting as a real athletic activity such as running. It is. If you have not been running at all and then you go out and run 12 miles in an hour, you will damage your body; likewise with knitting. Most knitters are mothers, and they have been caring for their family so they have some “forearm” fitness. But, if you plunge into a tough knitting project, you WILL damage your wrists. If you have not been knitting for 6 weeks, then no more than an hour of knitting per day, and increase by no more than an hour a day no more than once a month (or 10% per week which ever is less.) Hey, I know Christmas is coming, so start early; you do not want to be wearing a wrist brace over the holidays.
If you are a fit knitter and have build up to substantial “mileage’ per week (sorry, I am a runner) then keep it up and do some training every week. Staying in shape really will help your comeback schedule.
The effort to knit depends on a number of factors including yarn lubrication. This is one reason that I like the Cottage Craft yarns – they retain the spinning oils and work easily, they are lubricated.
When I knit with a dry yarn, I often keep a bit of Udderly Smooth (http://www.uddercream.com/products.html) on my hands. This is a lanolin-based cream for dry skin. It is non greasy and inexpensive. Again, I have no connection with the company, I tried a bunch of lotions, and this is what works for me. The cream adheres the yarn and helps to lubricate it. Also, I have trouble maitaining consistent yarn tension when I have dry hands. When my hands are very dry the cream helps me maintain uniform yarn tension. It then washes out of the yarn when I block the garment. (However, if I frog the yarn out, then roll the yarn into a ball and let it sit for a couple of years, the lanolin gets all sticky and I have to skein the yarn, and wash it before I can knit with it.)
I learned to knit using the small muscles in my forearms and hands. That is OK if you are knitting loosely. But if you are knitting tightly, you need to make sure that you are mostly using the large muscles in the upper arm and shoulder. Can you retrain yourself? I do not know. I am half-way through my retraining process – it is like an alcoholic only drinking on Mondays and Thursdays.
My approach to training myself to use my upper arms is to switch from the Continental method (yarn controlled by left hand) to the English method with the yarn in the right hand with a knitting stick. With a knitting stick, knitting is done on double pointed needles with the lower end of the right-hand needle anchored in the knitting stick. Pictures of knitting sticks may be seen at (http://www.daelnet.co.uk/features/knitting/history3.htm)
I made my own knitting sticks, and they work just fine. Someday soon, I will tell you how to make your own knitting sticks, or reach over and Google “knitting sticks” and you can find a place to buy commercially knitting sticks made out of Russian olive or maple. i have not tried the commercial ones, I just know that they are out there.