"My work just brought in the LifeSpan Fitness treadmill desks and they are a game changer. Surprisingly tough to get used to - my body has gotten so used to sitting down all day for work. Takes about 2 weeks to adapt to the change, but you really do see a major improvement. I don't feel so sluggish when 5 pm rolls around.
This is the specific model we use at work: https://www.lifespanfitness.com/workplace/treadmill-desks/tr800-dt5-treadmill-desk
No crazy bells and whistles, nothing too fancy. Really happy with it!"