The effects of stretching on knee flexor fatigue and perceived exertion

• Published in: Journal of sports sciences 2010-01, Vol.28 (2), p.219-226
• Main Authors: Heuser, Michael, Pincivero, Danny
• Format: Article
• Language: English
• Subjects: Adolescent; Adult; Biological and medical sciences; Effects; Fatigue; Female; Fundamental and applied biological sciences. Psychology; gender; Gender differences; Hamstring; Humans; isokinetic; Knee Joint - physiology; Leg; Male; Models, Biological; Muscle Contraction - physiology; Muscle Fatigue - physiology; Muscle Stretching Exercises; Muscle, Skeletal - physiology; Muscular system; Perception; Physical Exertion; Pliability; rating of perceived exertion; Sex Factors; Studies; Vertebrates: body movement. Posture. Locomotion. Flight. Swimming. Physical exercise. Rest. Sports; Young Adult
• ISSN: 0264-0414; 1466-447X
• DOI: 10.1080/02640410903460718

The objective of this study was to examine the effects of acute static muscle stretch on hamstring muscle fatigue and perceived exertion between young adult men and women. Twenty volunteers participated in two experimental sessions, in which we assessed maximal-effort isokinetic knee flexor force (90° · s −1 ) and the number of sub-maximal (50% maximal) knee flexor repetitions to the point of failure. Immediately before the sub-maximal contractions on one randomly selected session, participants received ten 30-s passive knee flexor muscle stretches. Perceived exertion was sampled with a modified Borg category-ratio scale following each sub-maximal repetition. Each participant's perceived exertion response was estimated every 10% across the sub-maximal repetitions, via linear interpolation and power-function modelling. The men generated significantly greater force than the women during both experimental sessions, while muscle stretching had no significant effect on the number of sub-maximal repetitions. When estimated via power-function modelling, perceived exertion increased at a significantly greater rate following muscle stretch. Perceived exertion was significantly greater for the women following muscle stretch than the men. The findings suggest that the elevation in perceived exertion following knee flexor muscle stretching may be greater in women than men, despite no significant alterations in mechanical measures of muscle fatigue.