Is EMS at sub-painful levels still effective?

Let’s say that the athlete has troubling really cranking up the voltage, either due to troublesome tendon attachments or a low pain threshhold. Is using the standard protocol of 10 reps x 10 seconds still effective if the intensity is high, but not crazy?

I’m referring to an intensity which is just starting to become painful.
If, as Charlie has stated, the electrical current favors the larger fast twitch motor units, aren’t these still being preferentially recruited, albeit in diminished numbers, at the slightly lower intensity?

And if it is still fast fibers being recuited first, this scenario does still has strength benefits for the athlete, corrrect?

Bump-Anyone with a thought in this area?