The critical threshold hypothesis proposes that performance fatigability during high-intensity exercise is tightly regulated by negative-feedback signals from the active muscles. We propose that performance fatigability is simply dependent on the exercise mode and intensity; the consequent adjustments, in skeletal muscle and the other physiological systems that support exercise, interact to modulate fatigue and determine exercise tolerance.
The magnitude of performance fatigability observed after high-intensity exercise is task-dependent, and not regulated to a peripheral critical threshold.
1Faculty of Health and Life Sciences, Northumbria University, Newcastle-upon-Tyne, United Kingdom;
2Water Research Group, School of Environmental Sciences and Development, Northwest University, Potchefstroom, South Africa
Address for correspondence: Dr. Kevin Thomas, Faculty of Health and Life Science, Department of Sport, Exercise and Rehabilitation, Northumbria University, Newcastle-upon-Tyne, NE1 8ST, UK (E-mail: firstname.lastname@example.org).
Accepted for publication: June 6, 2018.
Editor: Sandra K. Hunter, Ph.D., FACSM.