system
Given the following post, respond as if you're commenting on Reddit:
human
[Tron] If you're stuck in the Grid, time has slowed down for you in the real world. Why don't you continue to age?

I ask this because Kevin Flynn was trapped in the Grid for 20ish years and he aged only 20 years or so. I did the math and, to him, he would be hundreds (if not thousands) of years older. Why is he still alive and in decent health? 

Apparently a User can still bleed (shown in Tron: Legacy that proves his son is a User in the Games). So a User is still human to me.
gpt
The conversion of a human entity into a digital format creates a sort of temporal paradox. The form of a program allows the human mind to think and process their environment as quickly as the processor cycles for that system will allow, which is much faster than a pure human brain can manage, biologically. However, the human form still ages only the amount corresponding to the actual time that has passed. The form of the human does not degrade any quicker on the Grid than it would in the outside world.

**tl;dr** - Being on the Grid allows a human mind to live millisecond-by-millisecond without rapidly aging them because the same amount of time is passing.