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Physiologic Adaptations to Modifying Resistive Load and Time Under Tension During Expiratory Muscle Strength Training
Avery E Dakin1, Sydney Rau1, Katya Villarreal-Cavazos1
1Laboratory for the Study of Upper Airway Dysfunction, Department of Biobehavioral Sciences, Teachers College, Columbia University, New York, NY.
Summary
Modifying expiratory muscle strength training (EMST) parameters like load and time under tension impacts respiratory responses and effort. These findings are crucial for optimizing EMST exercise prescription for better results.
Area of Science:
- Respiratory Physiology
- Exercise Science
- Rehabilitation
Background:
- Expiratory muscle strength training (EMST) is used to improve respiratory function.
- Understanding how different training parameters affect physiological responses is key for effective prescription.
Purpose of the Study:
- To investigate the effects of varying resistive load and time under tension (TUT) during EMST.
- To analyze the impact on respiratory excursion, submental muscle activity, and perceived exertion.
- To explore task specificity between EMST, cough, and swallowing actions.
Main Methods:
- Twenty healthy adults performed EMST under four conditions varying load (50% and 75% maximal expiratory pressure) and TUT (0.2s and 1s).
- Respiratory bands, submental electromyography, and microphones measured outcomes.
- Data analyzed using multilevel models and pairwise comparisons.
Main Results:
- Significant differences in rib cage and abdominal excursion, submental excitation, and RPE were observed across EMST conditions.
- Submental excitation was significantly higher during the L75 (long TUT, 75% MEP) condition compared to swallowing.
- No significant differences were found in cough or swallowing tasks across most EMST conditions.
Conclusions:
- Exercise parameters like resistive load and TUT significantly influence acute physiological responses during EMST.
- Consideration of these parameters is vital for optimizing EMST exercise prescription and achieving desired adaptations.
- Future research should focus on the long-term effects of modified EMST parameters on cough and swallow function.
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