Influence of muscular contraction on vascular conductance during exercise above versus below critical power. Respir Physiol Neurobiol 2021 Nov;293:103718
Date
06/15/2021Pubmed ID
34126260Pubmed Central ID
PMC8877527DOI
10.1016/j.resp.2021.103718Scopus ID
2-s2.0-85107957347 (requires institutional sign-in at Scopus site) 7 CitationsAbstract
We tested the hypothesis that limb vascular conductance (LVC) would increase during the immediate recovery phase of dynamic exercise above, but not below, critical power (CP) indicating a threshold for muscular contraction-induced impedance of limb blood flow (LBF). CP (115 ± 26 W) was determined in 7 men and 7 women who subsequently performed ∼5 min of near-supine cycling exercise both below and above CP. LVC demonstrated a greater increase during immediate recovery and remained significantly higher following exercise above, compared to below, CP (all p < 0.001). Power output was associated with the immediate increases in LVC following exercise above, but not below, CP (p < 0.001; r = 0.85). Additionally, variance in percent LBF impedance was significantly lower above (CV: 10.7 %), compared to below (CV: 53.2 %), CP (p < 0.01). CP appears to represent a threshold above which the characteristics of LBF impedance by muscular contraction become intensity-dependent. These data suggest a critical level of LBF impedance relative to contraction intensity exists and, once attained, may promote the progressive metabolic and neuromuscular responses known to occur above CP.
Author List
Hammer SM, Hammond ST, Parr SK, Alexander AM, Turpin VG, White ZJ, Didier KD, Smith JR, Barstow TJ, Ade CJAuthor
Stephen T. Hammond Postdoctoral Fellow in the Medicine department at Medical College of WisconsinMESH terms used to index this publication - Major topics in bold
AdultBicycling
Blood Circulation
Electric Impedance
Exercise
Female
Femoral Artery
Humans
Lower Extremity
Male
Muscle Contraction
Muscle, Skeletal
Ultrasonography, Doppler
Young Adult
