Left ventricular twist mechanics during incremental cycling and knee extension exercise in healthy men
| Autor: | Joanna C. Richards, Nicholas Sculthorpe, John Hough, Alexander Beaumont |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2017 |
| Předmět: |
Adult
Male medicine.medical_specialty Sports medicine Adolescent Rotation Physiology Heart Ventricles Speckle tracking echocardiography Isometric exercise 030204 cardiovascular system & hematology Knee extension Ventricular Function Left 03 medical and health sciences 0302 clinical medicine Physiology (medical) medicine Humans Knee Orthopedics and Sports Medicine Twist Exercise business.industry Public Health Environmental and Occupational Health 030229 sport sciences General Medicine Mechanics Human physiology Left ventricle QP Echocardiography Original Article Cycling business Muscle Contraction |
| Zdroj: | European Journal of Applied Physiology |
| ISSN: | 1439-6319 |
| Popis: | PURPOSE: The objective of the present study was to investigate left ventricular (LV) twist mechanics in response to incremental cycling and isometric knee extension exercises.\ud METHODS: Twenty-six healthy male participants (age = 30.42 ± 6.17 years) were used to study peak twist mechanics at rest and during incremental semi-supine cycling at 30 and 60% work rate maximum (W max) and during short duration (15 s contractions) isometric knee extension at 40 and 75% maximum voluntary contraction (MVC), using two-dimensional speckle tracking echocardiography.\ud RESULTS: Data presented as mean ± standard deviation or median (interquartile range). LV twist increased from rest to 30% W max (13.21° ± 4.63° to 20.04° ± 4.76°, p < 0.001) then remained unchanged. LV systolic and diastolic twisting velocities progressively increased with exercise intensity during cycling from rest to 60% W max (twisting, 88.21° ± 20.51° to 209.05° ± 34.56° s(-1), p < 0.0001; untwisting, -93.90 (29.62)° to -267.31 (104.30)° s(-1), p < 0.0001). During the knee extension exercise, LV twist remained unchanged with progressive intensity (rest 13.40° ± 4.80° to 75% MVC 16.77° ± 5.54°, p > 0.05), whilst twisting velocity increased (rest 89.15° ± 21.77° s(-1) to 75% MVC 124.32° ± 34.89° s(-1), p < 0.01). Untwisting velocity remained unchanged from rest [-90.60 (27.19)° s(-1)] to 40% MVC (p > 0.05) then increased from 40 to 75% MVC [-98.44 (43.54)° s(-1) to -138.42 (73.29)° s(-1), p < 0.01]. Apical rotations and rotational velocities were greater than basal during all conditions and intensities (all p < 0.01).\ud CONCLUSION: Cycling increased LV twist to 30% W max which then remained unchanged thereafter, whereas twisting velocities showed further increases to greater intensities. A novel finding is that LV twist was unaffected by incremental knee extension, yet systolic and diastolic twisting velocities augmented with isometric exercise. |
| Databáze: | OpenAIRE |
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