Tags

Type your tag names separated by a space and hit enter

Neuromuscular function after a bout of low-load blood flow-restricted exercise.
Med Sci Sports Exerc. 2013 Jan; 45(1):67-74.MS

Abstract

PURPOSE

This study compared endurance and neuromuscular function after bouts of low-load (LL), high-load (HL), and LL blood flow-restricted (LL(BFR)) resistance exercise.

METHODS

Eight recreationally active male subjects completed three sets of dynamic knee extensions to volitional failure under three conditions: HL (70% peak torque), LL (20% peak torque), and LL(BFR) (20% peak torque with an occlusive cuff inflated to 180 mm Hg wrapped around the thigh). Before and immediately after exercise, isometric torque, central activation, electrically evoked torque, and muscle activation via surface EMG were measured.

RESULTS

Isometric torque and evoked torque decreased an average of 37% and 40%, respectively (P < 0.01) in all conditions after exercise. There were no differences in the toque decrements between the conditions (P > 0.05). Percent central activation did not change after any condition (P = 0.09). Rate of torque development declined an average of 26% after all three conditions (P = 0.003), and rate of half-relaxation time was depressed by 48% after the HL condition (P = 0.004) only. EMG amplitude was greater in the HL condition at the beginning and end of exercise compared with the LL and LL(BFR) conditions (P = 0.001). At the end of exercise, EMG amplitude rose 19% (P = 0.02) and was not different among conditions (P > 0.05). Subjects performed more repetitions during the LL and LL(BFR) conditions (P < 0.05).

CONCLUSION

Although LL and LL(BFR) resistance exercise to volitional failure exhibit lower levels of muscle activation than HL exercise, similar torque decrements occur after all bouts of resistance exercise, and the muscle fatigue can be attributed to peripheral factors.

Authors+Show Affiliations

University of New Hampshire, Durham, NH 03824, USA. summer.cook@unh.eduNo affiliation info availableNo affiliation info available

Pub Type(s)

Journal Article
Randomized Controlled Trial
Research Support, Non-U.S. Gov't

Language

eng

PubMed ID

22895371

Citation

Cook, Summer B., et al. "Neuromuscular Function After a Bout of Low-load Blood Flow-restricted Exercise." Medicine and Science in Sports and Exercise, vol. 45, no. 1, 2013, pp. 67-74.
Cook SB, Murphy BG, Labarbera KE. Neuromuscular function after a bout of low-load blood flow-restricted exercise. Med Sci Sports Exerc. 2013;45(1):67-74.
Cook, S. B., Murphy, B. G., & Labarbera, K. E. (2013). Neuromuscular function after a bout of low-load blood flow-restricted exercise. Medicine and Science in Sports and Exercise, 45(1), 67-74. https://doi.org/10.1249/MSS.0b013e31826c6fa8
Cook SB, Murphy BG, Labarbera KE. Neuromuscular Function After a Bout of Low-load Blood Flow-restricted Exercise. Med Sci Sports Exerc. 2013;45(1):67-74. PubMed PMID: 22895371.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Neuromuscular function after a bout of low-load blood flow-restricted exercise. AU - Cook,Summer B, AU - Murphy,Bethany G, AU - Labarbera,Katherine E, PY - 2012/8/17/entrez PY - 2012/8/17/pubmed PY - 2013/5/18/medline SP - 67 EP - 74 JF - Medicine and science in sports and exercise JO - Med Sci Sports Exerc VL - 45 IS - 1 N2 - PURPOSE: This study compared endurance and neuromuscular function after bouts of low-load (LL), high-load (HL), and LL blood flow-restricted (LL(BFR)) resistance exercise. METHODS: Eight recreationally active male subjects completed three sets of dynamic knee extensions to volitional failure under three conditions: HL (70% peak torque), LL (20% peak torque), and LL(BFR) (20% peak torque with an occlusive cuff inflated to 180 mm Hg wrapped around the thigh). Before and immediately after exercise, isometric torque, central activation, electrically evoked torque, and muscle activation via surface EMG were measured. RESULTS: Isometric torque and evoked torque decreased an average of 37% and 40%, respectively (P < 0.01) in all conditions after exercise. There were no differences in the toque decrements between the conditions (P > 0.05). Percent central activation did not change after any condition (P = 0.09). Rate of torque development declined an average of 26% after all three conditions (P = 0.003), and rate of half-relaxation time was depressed by 48% after the HL condition (P = 0.004) only. EMG amplitude was greater in the HL condition at the beginning and end of exercise compared with the LL and LL(BFR) conditions (P = 0.001). At the end of exercise, EMG amplitude rose 19% (P = 0.02) and was not different among conditions (P > 0.05). Subjects performed more repetitions during the LL and LL(BFR) conditions (P < 0.05). CONCLUSION: Although LL and LL(BFR) resistance exercise to volitional failure exhibit lower levels of muscle activation than HL exercise, similar torque decrements occur after all bouts of resistance exercise, and the muscle fatigue can be attributed to peripheral factors. SN - 1530-0315 UR - https://www.unboundmedicine.com/medline/citation/22895371/Neuromuscular_function_after_a_bout_of_low_load_blood_flow_restricted_exercise_ L2 - http://dx.doi.org/10.1249/MSS.0b013e31826c6fa8 DB - PRIME DP - Unbound Medicine ER -