The thought of those research dogs being hooked up to constant pace treadmills all day makes me sad. I suppose it's better than having bleach pipetted into their eyes, but it still seems wrong. Maybe they get the pleasure of that once this project is finished...
But, on topic: yes, freedom of movement and common sense is key. Squidge played on the beach for ages when she was a pup, and came on hour-long walks with us and the other two when we were back in Andorra. The difference to nowadays is that we didn't walk for all that time - we maybe only went half a kilometre out, and the same back, but she had loads of snuffling about in the woods, importantly learning how to move her body.