Daniel T Cannon, Fred W Kolkhorst, Daniel J Cipriani
{"title":"肌电图数据不支持运动期间肌肉纤维的渐进式补充,表现出VO2缓慢成分。","authors":"Daniel T Cannon, Fred W Kolkhorst, Daniel J Cipriani","doi":"10.2114/jpa2.26.541","DOIUrl":null,"url":null,"abstract":"<p><p>The origin of the slow component (SC) of oxygen uptake kinetics, presenting during exercise above the ventilatory threshold (VT), remains unclear. Possible physiologic mechanisms include a progressive recruitment of type II muscle fibers. The purpose of this study was to examine alterations in muscle activity through electromyography (EMG) and mean power frequency (MPF) analysis during heavy cycling exercise. Eight trained cyclists (mean +/- S.E.; age = 30 +/- 3 years, height = 1771 +/- 4 cm, weight = 73.8 +/- 6.5 kg, VO2max = 4.33 +/- 0.28 l min(-1)) completed transitions from 20W to a workload equaling 50% of the difference between V(T) and VO2max. VO2 was monitored using a breath-by-breath measurement system, and EMG data were gathered from surface electrodes placed on the gastrocnemius lateralis and vastus lateralis oblique. Breath-by-breath data were time aligned, averaged, interpolated to 1-s intervals, and modeled with non-linear regression. Mean power frequency (MPF) and RMS EMG values were calculated for each minute during the exercise bout. Additionally, MPF was determined using both isolated EMG bursts and complete pedal revolutions. All subjects exhibited a VO2 SC (mean amplitude = 0.98 +/- 0.16 l min(-1)), yet no significant differences were observed during the exercise bout in MPF or RMS EMG data (p > 0.05) using either analysis technique. While it is possible that the sensitivity of EMG may be insufficient to identify changes in muscle activity theorized to affect the VO2 SC, the data indicated no relationship between MPF/EMG and the SC during heavy cycling.</p>","PeriodicalId":48730,"journal":{"name":"Journal of Physiological Anthropology","volume":null,"pages":null},"PeriodicalIF":3.3000,"publicationDate":"2007-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.2114/jpa2.26.541","citationCount":"20","resultStr":"{\"title\":\"Electromyographic data do not support a progressive recruitment of muscle fibers during exercise exhibiting a VO2 slow component.\",\"authors\":\"Daniel T Cannon, Fred W Kolkhorst, Daniel J Cipriani\",\"doi\":\"10.2114/jpa2.26.541\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<p><p>The origin of the slow component (SC) of oxygen uptake kinetics, presenting during exercise above the ventilatory threshold (VT), remains unclear. Possible physiologic mechanisms include a progressive recruitment of type II muscle fibers. The purpose of this study was to examine alterations in muscle activity through electromyography (EMG) and mean power frequency (MPF) analysis during heavy cycling exercise. Eight trained cyclists (mean +/- S.E.; age = 30 +/- 3 years, height = 1771 +/- 4 cm, weight = 73.8 +/- 6.5 kg, VO2max = 4.33 +/- 0.28 l min(-1)) completed transitions from 20W to a workload equaling 50% of the difference between V(T) and VO2max. VO2 was monitored using a breath-by-breath measurement system, and EMG data were gathered from surface electrodes placed on the gastrocnemius lateralis and vastus lateralis oblique. Breath-by-breath data were time aligned, averaged, interpolated to 1-s intervals, and modeled with non-linear regression. Mean power frequency (MPF) and RMS EMG values were calculated for each minute during the exercise bout. Additionally, MPF was determined using both isolated EMG bursts and complete pedal revolutions. All subjects exhibited a VO2 SC (mean amplitude = 0.98 +/- 0.16 l min(-1)), yet no significant differences were observed during the exercise bout in MPF or RMS EMG data (p > 0.05) using either analysis technique. While it is possible that the sensitivity of EMG may be insufficient to identify changes in muscle activity theorized to affect the VO2 SC, the data indicated no relationship between MPF/EMG and the SC during heavy cycling.</p>\",\"PeriodicalId\":48730,\"journal\":{\"name\":\"Journal of Physiological Anthropology\",\"volume\":null,\"pages\":null},\"PeriodicalIF\":3.3000,\"publicationDate\":\"2007-09-01\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"https://sci-hub-pdf.com/10.2114/jpa2.26.541\",\"citationCount\":\"20\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Journal of Physiological Anthropology\",\"FirstCategoryId\":\"3\",\"ListUrlMain\":\"https://doi.org/10.2114/jpa2.26.541\",\"RegionNum\":4,\"RegionCategory\":\"医学\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q1\",\"JCRName\":\"PHYSIOLOGY\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Journal of Physiological Anthropology","FirstCategoryId":"3","ListUrlMain":"https://doi.org/10.2114/jpa2.26.541","RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"PHYSIOLOGY","Score":null,"Total":0}
Electromyographic data do not support a progressive recruitment of muscle fibers during exercise exhibiting a VO2 slow component.
The origin of the slow component (SC) of oxygen uptake kinetics, presenting during exercise above the ventilatory threshold (VT), remains unclear. Possible physiologic mechanisms include a progressive recruitment of type II muscle fibers. The purpose of this study was to examine alterations in muscle activity through electromyography (EMG) and mean power frequency (MPF) analysis during heavy cycling exercise. Eight trained cyclists (mean +/- S.E.; age = 30 +/- 3 years, height = 1771 +/- 4 cm, weight = 73.8 +/- 6.5 kg, VO2max = 4.33 +/- 0.28 l min(-1)) completed transitions from 20W to a workload equaling 50% of the difference between V(T) and VO2max. VO2 was monitored using a breath-by-breath measurement system, and EMG data were gathered from surface electrodes placed on the gastrocnemius lateralis and vastus lateralis oblique. Breath-by-breath data were time aligned, averaged, interpolated to 1-s intervals, and modeled with non-linear regression. Mean power frequency (MPF) and RMS EMG values were calculated for each minute during the exercise bout. Additionally, MPF was determined using both isolated EMG bursts and complete pedal revolutions. All subjects exhibited a VO2 SC (mean amplitude = 0.98 +/- 0.16 l min(-1)), yet no significant differences were observed during the exercise bout in MPF or RMS EMG data (p > 0.05) using either analysis technique. While it is possible that the sensitivity of EMG may be insufficient to identify changes in muscle activity theorized to affect the VO2 SC, the data indicated no relationship between MPF/EMG and the SC during heavy cycling.
期刊介绍:
Journal of Physiological Anthropology (JPA) is an open access, peer-reviewed journal that publishes research on the physiological functions of modern mankind, with an emphasis on the physical and bio-cultural effects on human adaptability to the current environment.
The objective of JPA is to evaluate physiological adaptations to modern living environments, and to publish research from different scientific fields concerned with environmental impact on human life.
Topic areas include, but are not limited to:
environmental physiology
bio-cultural environment
living environment
epigenetic adaptation
development and growth
age and sex differences
nutrition and morphology
physical fitness and health
Journal of Physiological Anthropology is the official journal of the Japan Society of Physiological Anthropology.