It's when you are low and slow and try to pull up with the elevator that you may stall the aircraft. You need to push the throttle to gain some airspeed.
It's not a question of whether you are strong enough to move the flight controls.
The only thing the hydraulics do for you is to reduce your effort in moving those controls.
Control surfaces don't magically make the plane go up or down, or left or right. The only way they work is by pushing against the air flowing over them.
If there is not enough airflow over the actual controls - ailerons, elevator, rudder - you won't be able to control the airplane.
And if there isn't enough airflow over the wings, they won't provide lift. That is when you stall and lose all control, until you find a way to increase your airspeed and get some air moving over the wings and flight controls, so they have something to push against.
Source: my basic pilot training where I practiced stalls and spins and all kinds of loss of control.
Anybody who flew a badly trimmed plane at high speed will disagree. Of course more airflow over the wings will mean your GA cessna 172 controls require more human strength to operate. They are also more effective as you say, but that's not what the previous poster meant.
I think a good rule of thumb would be heading towards the ground fastly isn't a good thing