My first reaction was, I'd rather just focus on and enjoy the quilting, but there are some good suggestions here.
I'll add one: Keep a set of dumbbells by you, and each time you finish a section, do a quick set of 10 or 12 reps with your dumbbells. Do a different lift each time, like a set of biceps curls one time, then a set of overhead lifts (I don't know the actual names of these) the next time.
By section, you define what a section is for you, whether it's a quilt block or just a seam if you sew by hand, or cutting a set of strips, or even every 20 minutes or so.