Twitch potentiation after fatiguing exercise in man

Stephen Alway, R. L. Hughson, H. J. Green, A. E. Patla, J. S. Frank

Research output: Contribution to journalArticle

42 Citations (Scopus)

Abstract

Twitch potentiation was studied in the human triceps surae complex before and after intermittent maximal voluntary contractions or electrical stimulation at 20 Hz. Both forms of exercise were conducted with intact circulation for a maximum of 10 min or with circulatory occlusion until force output declined 50%. The relative potentiation was determined when a control twitch was compared to a twitch obtained after 5 s of maximal voluntary plantar flexion. The unpotentiated twitch torque (PT) and potentiated twitch torque (PT*) were reduced most severely after voluntary ischemic exercise (63.2% and 52.5% respectively, (P<0.001)). However, the relative potentiation (PT*/PT) immediately after voluntary ischemic exercise increased to 1.65±0.18 from 1.22±0.13 at rest. Both PT and PT* recovered quickly after exercise. At rest, twitch contraction time (CT) and one-half relaxation time (1/2 RT) in the unpotentiated twitch were longer than that of contraction (CT*) and one-half relaxation time (1/2 RT*) in the potentiated twitch. Following non-occluded exercise, CT, CT*, 1/2 RT and 1/2 RT* were shortened relative to rest. After ischemic exercise CT and CT* were shortened although 1/2 RT and 1/2 RT* increased relative to rest. Both CT* and 1/2 RT* quickly recovered to pre-exercise values by 5 min post-exercise. Ratios of potentiated/control twitch parameters were not altered after nonoccluded exercise, but were increased after ischemic exercise. These results suggest that the mechanisms of fatigue which depress voluntary torque and twitch and potentiated twitch torques, do not interfere with the extent of potentiation after fatiguing exercise.

Original languageEnglish (US)
Pages (from-to)461-466
Number of pages6
JournalEuropean Journal of Applied Physiology and Occupational Physiology
Volume56
Issue number4
DOIs
StatePublished - Jul 1 1987

Fingerprint

Torque
Exercise
Electric Stimulation
Fatigue

All Science Journal Classification (ASJC) codes

  • Physiology
  • Public Health, Environmental and Occupational Health

Cite this

Twitch potentiation after fatiguing exercise in man. / Alway, Stephen; Hughson, R. L.; Green, H. J.; Patla, A. E.; Frank, J. S.

In: European Journal of Applied Physiology and Occupational Physiology, Vol. 56, No. 4, 01.07.1987, p. 461-466.

Research output: Contribution to journalArticle

Alway, Stephen ; Hughson, R. L. ; Green, H. J. ; Patla, A. E. ; Frank, J. S. / Twitch potentiation after fatiguing exercise in man. In: European Journal of Applied Physiology and Occupational Physiology. 1987 ; Vol. 56, No. 4. pp. 461-466.
@article{46f6f7d004b34eba9e2444cb3fc22b1a,
title = "Twitch potentiation after fatiguing exercise in man",
abstract = "Twitch potentiation was studied in the human triceps surae complex before and after intermittent maximal voluntary contractions or electrical stimulation at 20 Hz. Both forms of exercise were conducted with intact circulation for a maximum of 10 min or with circulatory occlusion until force output declined 50{\%}. The relative potentiation was determined when a control twitch was compared to a twitch obtained after 5 s of maximal voluntary plantar flexion. The unpotentiated twitch torque (PT) and potentiated twitch torque (PT*) were reduced most severely after voluntary ischemic exercise (63.2{\%} and 52.5{\%} respectively, (P<0.001)). However, the relative potentiation (PT*/PT) immediately after voluntary ischemic exercise increased to 1.65±0.18 from 1.22±0.13 at rest. Both PT and PT* recovered quickly after exercise. At rest, twitch contraction time (CT) and one-half relaxation time (1/2 RT) in the unpotentiated twitch were longer than that of contraction (CT*) and one-half relaxation time (1/2 RT*) in the potentiated twitch. Following non-occluded exercise, CT, CT*, 1/2 RT and 1/2 RT* were shortened relative to rest. After ischemic exercise CT and CT* were shortened although 1/2 RT and 1/2 RT* increased relative to rest. Both CT* and 1/2 RT* quickly recovered to pre-exercise values by 5 min post-exercise. Ratios of potentiated/control twitch parameters were not altered after nonoccluded exercise, but were increased after ischemic exercise. These results suggest that the mechanisms of fatigue which depress voluntary torque and twitch and potentiated twitch torques, do not interfere with the extent of potentiation after fatiguing exercise.",
author = "Stephen Alway and Hughson, {R. L.} and Green, {H. J.} and Patla, {A. E.} and Frank, {J. S.}",
year = "1987",
month = "7",
day = "1",
doi = "10.1007/BF00417776",
language = "English (US)",
volume = "56",
pages = "461--466",
journal = "European Journal of Applied Physiology",
issn = "1439-6319",
publisher = "Springer Verlag",
number = "4",

}

TY - JOUR

T1 - Twitch potentiation after fatiguing exercise in man

AU - Alway, Stephen

AU - Hughson, R. L.

AU - Green, H. J.

AU - Patla, A. E.

AU - Frank, J. S.

PY - 1987/7/1

Y1 - 1987/7/1

N2 - Twitch potentiation was studied in the human triceps surae complex before and after intermittent maximal voluntary contractions or electrical stimulation at 20 Hz. Both forms of exercise were conducted with intact circulation for a maximum of 10 min or with circulatory occlusion until force output declined 50%. The relative potentiation was determined when a control twitch was compared to a twitch obtained after 5 s of maximal voluntary plantar flexion. The unpotentiated twitch torque (PT) and potentiated twitch torque (PT*) were reduced most severely after voluntary ischemic exercise (63.2% and 52.5% respectively, (P<0.001)). However, the relative potentiation (PT*/PT) immediately after voluntary ischemic exercise increased to 1.65±0.18 from 1.22±0.13 at rest. Both PT and PT* recovered quickly after exercise. At rest, twitch contraction time (CT) and one-half relaxation time (1/2 RT) in the unpotentiated twitch were longer than that of contraction (CT*) and one-half relaxation time (1/2 RT*) in the potentiated twitch. Following non-occluded exercise, CT, CT*, 1/2 RT and 1/2 RT* were shortened relative to rest. After ischemic exercise CT and CT* were shortened although 1/2 RT and 1/2 RT* increased relative to rest. Both CT* and 1/2 RT* quickly recovered to pre-exercise values by 5 min post-exercise. Ratios of potentiated/control twitch parameters were not altered after nonoccluded exercise, but were increased after ischemic exercise. These results suggest that the mechanisms of fatigue which depress voluntary torque and twitch and potentiated twitch torques, do not interfere with the extent of potentiation after fatiguing exercise.

AB - Twitch potentiation was studied in the human triceps surae complex before and after intermittent maximal voluntary contractions or electrical stimulation at 20 Hz. Both forms of exercise were conducted with intact circulation for a maximum of 10 min or with circulatory occlusion until force output declined 50%. The relative potentiation was determined when a control twitch was compared to a twitch obtained after 5 s of maximal voluntary plantar flexion. The unpotentiated twitch torque (PT) and potentiated twitch torque (PT*) were reduced most severely after voluntary ischemic exercise (63.2% and 52.5% respectively, (P<0.001)). However, the relative potentiation (PT*/PT) immediately after voluntary ischemic exercise increased to 1.65±0.18 from 1.22±0.13 at rest. Both PT and PT* recovered quickly after exercise. At rest, twitch contraction time (CT) and one-half relaxation time (1/2 RT) in the unpotentiated twitch were longer than that of contraction (CT*) and one-half relaxation time (1/2 RT*) in the potentiated twitch. Following non-occluded exercise, CT, CT*, 1/2 RT and 1/2 RT* were shortened relative to rest. After ischemic exercise CT and CT* were shortened although 1/2 RT and 1/2 RT* increased relative to rest. Both CT* and 1/2 RT* quickly recovered to pre-exercise values by 5 min post-exercise. Ratios of potentiated/control twitch parameters were not altered after nonoccluded exercise, but were increased after ischemic exercise. These results suggest that the mechanisms of fatigue which depress voluntary torque and twitch and potentiated twitch torques, do not interfere with the extent of potentiation after fatiguing exercise.

UR - http://www.scopus.com/inward/record.url?scp=0023628455&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0023628455&partnerID=8YFLogxK

U2 - 10.1007/BF00417776

DO - 10.1007/BF00417776

M3 - Article

VL - 56

SP - 461

EP - 466

JO - European Journal of Applied Physiology

JF - European Journal of Applied Physiology

SN - 1439-6319

IS - 4

ER -