While it can't substitute for a rigorous workout (say, one on a traditional treadmill), an under-desk treadmill, like the best under-desk exercise bikes, can help you burn calories and get some steps while sending emails, watching TV, or frankly, any otherwise sedentary activity. ​ Best Luxury Under Desk Treadmill: InMovement Unsit Under Desk Treadmill​​ For the past two years, Men's Health's fitness team has researched and tested over a dozen under-desk treadmills from top home gym and cardio machine brands to find the best treadmill desks to buy in 2026.