Desk

You will need to stand when you sing, and should be standing when practicing speaking.

Standing Desk

You will need a standing desk. I have a makeshift standing desk made out of a small writing desk that stands on a table.

Physically shifting a computer monitor between your sitting and standing desk is tiresome. I recommend buying a second a second computer monitor.

Underdesk Treadmill

I practice singing while walking on a treadmill. Underdesk treadmills are a vital investment for the intellectually inclined, who being drawn to intellectual activities would otherwise lose out on physical activity. I eat my meals on the treadmill so try to increase my exercise. It would be good work while on the treadmill but it is difficult to do cognitively demanding tasks walking or even standing up, because there is less blood getting to your brain. I believe the stress of intellectual work is mostly the result of keeping you blood pressure high enough to get the required amount of blood to your brain.

I recommend the LifeSpan TR5000.