They
showed that ES at a frequency below 40–50 Hz solicited more
and more Type I, slow-twitch muscle fibers that are more
resistant to muscle fatigue. Higher frequencies solicited more
Type IIa and IIb fast-twitch muscle fibers that are easily
fatigued. Kesar and Binder-Macleod [29] reported that lowfrequency
ES (11 Hz) associated to long-pulse duration (PD)
(600 ms) is less tiring for the muscles than medium frequency
ES (30 Hz) coupled to medium-PD (150 ms) or high frequency