An inmate that is about ready to be executed is usually given some medicine to sedate them and calm them down beforehand.
So the inmate is kind of already drugged so they are more relaxed as they're headed to the room to be executed.
Most inmates do not resist the walk to the execution or resist when they're putting them on the gurney to be executed.
Also some death row inmates accept the fact and are ready to get the execution over with instead of sitting on death row any longer.
Death Row inmates can sit on death row in a dark cell for around 15 and even 25 years before being executed so after living that life they're ready to just die.
And if the death row inmate did resist they would just bring in more guards to subdue and manhandle the inmate so they would still not get out of it by resisting so resisting would not work anyway.
They would still be eventually strapped down to the gurney and executed.