Submaximal neuromuscular economy is related to cardiorespiratory fitness in endurance-trained runners

William P McCormack; Caleb J Yoo; Kiana M Harpstrite; Todd C Shoepe; Caitlin A Jennings; Lance M Capel; Carolyne E Copley; William P McCormack 3rd

doi:10.1016/j.jelekin.2019.06.006

Submaximal neuromuscular economy is related to cardiorespiratory fitness in endurance-trained runners

J Electromyogr Kinesiol. 2019 Oct:48:69-75. doi: 10.1016/j.jelekin.2019.06.006. Epub 2019 Jun 19.

Authors

William P McCormack¹, Caleb J Yoo², Kiana M Harpstrite², Todd C Shoepe², Caitlin A Jennings³, Lance M Capel⁴, Carolyne E Copley⁵, William P McCormack 3rd⁶

Affiliations

¹ Department of Health and Human Sciences, Loyola Marymount University, Los Angeles, CA, United States. Electronic address: william.mccormack@lmu.edu.
² Department of Health and Human Sciences, Loyola Marymount University, Los Angeles, CA, United States.
³ College of Chiropractic, University of Western States, Portland, OR, United States.
⁴ Fisherman Labs, El Segundo, CA, United States.
⁵ Emergency Department, Mission Hospital Medical Center, Mission Viejo, CA, United States.
⁶ Department of Physics, University of California, Berkeley, CA, United States.

PMID: 31234056
DOI: 10.1016/j.jelekin.2019.06.006

Abstract

A number of factors determine neuromuscular economy (NE) and running economy (RE) in endurance-trained runners. The purpose of this investigation was to examine the relationship between aerobic fitness and NE in endurance-trained runners. Twenty-seven endurance-trained runners (25.1 ± 10.2 y) completed a maximal voluntary isometric contraction of the leg extensors to measure maximal electromyography (EMG_max) amplitude of the vastus lateralis (VL) and rectus femoris (RF), a steady-state treadmill run at 9.66, 11.27, and 12.87 km∙hr^-1 and a maximal graded exercise test. Participants were outfitted with surface electrodes over the VL and RF muscles to record EMG amplitude throughout each test. During the steady-state test, the EMG (as a percentage of EMG_max) and oxygen consumption (VO₂) over the final minute of each stage were established and considered NE and RE, respectively. Pearson product moment correlations were used to determine the relationships between VO₂max and velocity at VO₂max (vVO₂max) and NE and RE. The results revealed significant negative correlations between VO₂max and vVO₂max and relative NE and RE at all three speeds. In addition, there were significant correlations between relative RE and NE at all three speeds. These results indicate that faster runners have improved NE and RE when expressed as a relative measure.

Keywords: Electromyography; Running economy; Running performance; VO(2)max.

MeSH terms

Adolescent
Adult
Athletes*
Cardiorespiratory Fitness*
Electromyography
Endurance Training*
Exercise Test
Female
Humans
Isometric Contraction
Male
Oxygen Consumption
Physical Endurance
Quadriceps Muscle / physiology*
Running / physiology*
Young Adult