Perceived exertion, electromyography, and blood lactate during acute bouts of resistance exercise

Utter, Alan C. Ph.D., M.P.H., FACSM

Medicine & Science in Sports & Exercise: March 2002 - Volume 34 - Issue 3 - p 560
APPLIED SCIENCES: Psychobiology and Social Sciences: Guest Editorial to accompany

In the past 25 years, the body of knowledge concerned with “perceived exertion” has generated approximately 450 published articles. In the past 10 years, there has been increasing interest in various physiological factors that mediate ratings of perceived exertion (RPE). The understanding and application of RPE in both clinical and competitive sport setting requires the knowledge of the underlying physiological and psychological processes being subjectively monitored and evaluated. Exercise physiologists and sport psychologists are challenged with unraveling the interactive nature of a complex human response such as the perception of muscular effort, which unquestionably is a composite of many inputs, including, but not limited to, physiological, psychological, and sociological.

The preceding paper by Lagally et al. provides an intriguing approach in attempting to determine the role that select physiological variables may have in mediating the intensity of exertional perceptions during resistance exercise. Among exercise psychobiologists, it is well known that physiological responses to an exercise stimulus mediate the intensity of perceptual signals of exertion by acting independently or collectively in altering tension-producing properties of skeletal muscle. The subsequent changes in skeletal muscle tension are monitored through a common neurophysiological pathway that transmits exertional signals from the motor to sensory cortex. The neurophysiological signal is consciously interpreted by the sensory cortex as effort sensation. Few studies have attempted with sound experimental methods to explore complex neurophysiological mechanisms such as electromyographic activity and blood lactic acid, and their potential role in mediating exertional perceptions during dynamic resistance exercise. Lagally et al. have laid the foundation with solid experimental design to promote and foster future research that will build theoretical models to assist in explaining human perception to physical resistive effort.

From a practical application perspective, RPE has been primarily used in various clinical settings to assess exercise tolerance and to prescribe and regulate therapeutic exercise intensity during dynamic modes of exercise. The systematic quantification of perceived exertion increases the clinical sensitivity of disease diagnosis, exercise evaluation, and the assessment of physical work capabilities. These applications assume that perceptual responses have corollary physiological mediators that are specific to the type of activity employed (i.e., resistance exercise) as demonstrated in the paper of Lagally et al. The monitoring of RPE during resistance exercise to evaluate functional tolerance, prescribe intensity, track-training adaptations, and potentially discriminate between normal and pathological conditions is in its stages of infancy. The clinical diagnosis of coronary artery and pulmonary diseases, and subsequent classification of disease severity can be facilitated by comparing RPE at fixed submaximal dynamic workloads between normal individuals and patients with various degrees of illness. By extension, future research should elucidate the role perceptual responses may play in the diagnostic discrimination of various diseases that have muscular strength and endurance limitations, such as muscle-wasting disorders, osteoporosis, arthritis, and diabetes. The preceding paper presents an engaging view into the complex flow of neurosensory information from a physical stimulus (i.e., resistance exercise) to a perceptual response, and it should serve as the impetus behind future research initiatives designed to expand our knowledge base in the area of perceived exertion and resistance exercise.

©2002The American College of Sports Medicine