Related Experiment Video
Updated: Jul 25, 2026
06:00
Determining The Electromyographic Fatigue Threshold Following a Single Visit Exercise Test
Published on: July 27, 2015
13.3K
The electromyographic threshold in boys and men
Brynlynn Pitt1, Raffy Dotan, Jordan Millar
1Applied Physiology Laboratory, Faculty of Applied Health Sciences, Brock University, 500 Glenridge Ave, St. Catharines, ON, L2T 2Y1, Canada.
European Journal of Applied Physiology
|January 16, 2015
Summary
Boys exhibit a higher electromyographic threshold (EMGTh) during exercise compared to men, indicating delayed type-II motor unit recruitment. This finding suggests a common factor underlying differences in exercise physiology between children and adults.
Area of Science:
- Exercise Physiology
- Pediatric Physiology
- Motor Unit Recruitment
Background:
- Children possess higher lactate (LaTh) and ventilatory (VeTh) thresholds than adults.
- This difference may stem from lower type-II motor-unit (MU) recruitment in children.
- The electromyographic threshold (EMGTh), indicative of accelerated type-II MU recruitment, has primarily been studied in adults.
Purpose of the Study:
- To compare the relative exercise intensity at which the EMGTh occurs in boys versus men.
- Investigate age-related differences in motor unit recruitment patterns during exercise.
Main Methods:
- 23 boys (11.1 ± 1.1 years) and 21 men (23.4 ± 4.1 years) with similar habitual physical activity and peak oxygen consumption (VO2pk) participated.
- Ramped cycle ergometry to volitional exhaustion was performed with surface EMG recorded from the vastus lateralis muscles.
- The electromyographic threshold (EMGTh) was determined from the composite EMG root mean square (EMGRMS) using regression analysis.
Main Results:
- EMGTh was detected in 78.3% of boys and 95.2% of men.
- Boys demonstrated a significantly higher EMGTh compared to men (86.4 ± 9.6% vs. 79.7 ± 10.0% of peak power output).
- This pattern remained consistent when EMGTh was expressed as a percentage of VO2pk.
Conclusions:
- The higher EMGTh in boys suggests delayed utilization of type-II MUs during progressive exercise compared to men.
- These findings support the hypothesis of a common underlying factor contributing to differences in LaTh, VeTh, and EMGTh between children and adults.
- This research provides insights into developmental differences in neuromuscular responses to exercise.
