0123 GMT November 13, 2019
A University of Kansas study shows that the communication between the brain and quadriceps muscles of people who take part in endurance training, such as running long distances, is different than those who regularly took part in resistance training and those who were sedentary. The findings may offer clues to the type of physical activity humans are most naturally suited to, Science Daily reported.
Trent Herda, an assistant professor of health, sport and exercise sciences, and Michael Trevino, a doctoral student, conducted studies in which they measured muscle responses of five people who regularly run long distances, five who regularly lift weights and five sedentary individuals who regularly do neither.
Among the findings, Herda and Trevino showed that the quadriceps muscle fibers of the endurance trainers were able to fire more rapidly.
"The communication between the brains and their muscles was slightly different than the resistance trainers and sedentary individuals," Herda said of endurance trainers. "This information also suggested that resistance trainers and those who are sedentary were more likely to fatigue sooner, among other things."
Participants wore mechanomyographic and electromyographic electrode sensors on their quadriceps muscle and extended their leg while seated. The researchers measured submaximal contraction and total force by having participants extend their leg, then exert more force, attempting to achieve from 40 to 70 percent of total force, which they could see represented in real time on a computer screen.
While it is not immediately clear why the communication between the brain and muscle was different as a result of different types of exercise as evidenced by the difference in rates of muscle fibers firing, Herda said it offers leads for new means of research into neuromechanical differences in muscle function, muscle performance, muscle stiffness and other areas. It also provides several clues into the type of exercise humans are more naturally built for.