https://theconversation.com/dangers-of-a-sedentary-covid-19-lockdown-inactivity-can-take-a-toll-on-health-in-just-two-weeks-149666

Insulin resistance (a warning sign for the development of type 2 diabetes), reduced muscle mass, increased body fat and poor sleep quality are just some of the health concernscaused by physical inactivity. Physical inactivity is also a major contributor to poor mental health and social isolation, which can be particularly problematic for older adults.

The health effects of inactivity start piling up within days.