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Updated: Apr 4, 2026
Ex Vivo Assessment of Contractility, Fatigability and Alternans in Isolated Skeletal Muscles
Published on: November 1, 2012
Effects of stimulation frequency, amplitude, and impulse width on muscle fatigue
Michael Behringer1, Sebastian Grützner1, Johannes Montag1
1Institute for Training Science and Sport Informatics, German Sport University Cologne, Am Sportpark Müngersdorf, 50933, Cologne, Germany.
Introduction:
We investigated the effect of stimulation intensity (in percent of maximal tolerated stimulation current, mTSC), frequency, and impulse width on muscle fatigue.
Methods:
Using a randomized crossover design, 6 parameter combinations (80% mTSC, 80 Hz, 400 μs; 60% mTSC, 80 Hz, 400 μs; 80% mTSC, 20 Hz, 400 μs; 60% mTSC, 20 Hz, 400 μs; 80% mTSC, 80 Hz, 150 μs; 60% mTSC, 80 Hz, 150 μs) were tested in both legs of 13 athletic men (age 26 ± 2.3). The slope of the linear regression line over all tetani (FIS) and the number of tetani whose force was above 50% of the initial tetanus (FIN) were used to quantify fatigue.
Results:
FIS and FIN were significantly lower in high-frequency protocols. No effects on FIS and FIN were found for intensity and impulse width.
Conclusions:
Stimulation frequency, but not impulse width or intensity, affected fatigue kinetics.
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