Gravity drains leg fluids down and gives exactly that feeling Tam, and it makes the muscle fibers so waterlogged they don't work right. Can you take a break mid-day to put your legs up (way up)? Athletes sometimes get on a bed, ass against wall and legs up against the wall, and read a book, to drain lactic acid (byproduct of workouts).

Sitting long periods can also trap leg fluids in the lower leg-- the veins on the backside of the knee/upper leg get compressed so flow back towards the heart is lessened.

Taking BP meds that add leg edema? Many do.... If so, it's time to tell the doc to try a new med or med combo. Or, you may need to explore compression stockings to help get the blood back up the leg towards the heart.

Not having DVT are you dear?

~Susan