Cubii and DesckCycle are probably the two leading brands when it comes to under-desk exercise solutions, and the (Opens in a new window)(opens in a new tab) is one of the former's best ellipticals.

Source: https://mashable.com/uk/roundup/best-under-desk-cycles-and-ellipticals-uk

For instance, under-desk treadmills feature lower max speeds with fewer features but in return, they’re more portable and take up a smaller footprint, making them a solid choice for those working in apartments or home offices.

Source: https://www.forbes.com/sites/forbes-personal-shopper/article/best-under-desk-treadmills/

The best under-desk treadmills can help you meet your fitness goals while you work.

Source: https://www.forbes.com/sites/forbes-personal-shopper/article/best-under-desk-treadmills/

What is the best under-desk treadmill?

Source: https://mashable.com/uk/roundup/best-under-desk-treadmills-uk