scholarly journals Group III/IV muscle afferents limit the intramuscular metabolic perturbation during whole body exercise in humans

2016 ◽  
Vol 594 (18) ◽  
pp. 5303-5315 ◽  
Author(s):  
Gregory M. Blain ◽  
Tyler S. Mangum ◽  
Simranjit K. Sidhu ◽  
Joshua C. Weavil ◽  
Thomas J. Hureau ◽  
...  
Keyword(s):  
Muscle Afferents ◽  
Whole Body ◽  
Group Iii ◽  
Metabolic Perturbation ◽  
Exercise In Humans

The Role of Group III/IV Muscle Afferents in Regulating the Hemodynamic Response to Whole Body Exercise

2020 ◽  
Vol 34 (S1) ◽  
pp. 1-1
Author(s):  
Taylor S. Thurston ◽  
Josh C. Weavil ◽  
Vincent P. Georgescu ◽  
Ryan M. Broxterman ◽  
Hsuan-Yu Wan ◽  
...  
Keyword(s):  
Hemodynamic Response ◽  
Muscle Afferents ◽  
Whole Body ◽  
Group Iii

Group III/IV Muscle Afferents Restrict Intramuscular Metabolic Perturbation In Exercising Humans

2015 ◽  
Vol 47 ◽  
pp. 329
Author(s):  
Gregory M. Blain ◽  
Tyler S. Mangum ◽  
Simranjit K. Sidhu ◽  
Joshua C. Weavil ◽  
Russell S. Richardson ◽  
...  
Keyword(s):  
Muscle Afferents ◽  
Group Iii ◽  
Metabolic Perturbation

scholarly journals Pharmacological attenuation of group III/IV muscle afferents improves endurance performance when oxygen delivery to locomotor muscles is preserved

2019 ◽  
Vol 127 (5) ◽  
pp. 1257-1266 ◽  
Author(s):  
Thomas J. Hureau ◽  
Joshua C. Weavil ◽  
Taylor S. Thurston ◽  
Hsuan-Yu Wan ◽  
Jayson R. Gifford ◽  
...  
Keyword(s):  
Endurance Exercise ◽  
Exercise Performance ◽  
Muscle Activation ◽  
Time Trial ◽  
Endurance Performance ◽  
Muscle Afferents ◽  
Afferent Feedback ◽  
Whole Body ◽  
Group Iii ◽  
Muscle Afferent

We sought to investigate the role of group III/IV muscle afferents in limiting endurance exercise performance, independently of their role in optimizing locomotor muscle O2 delivery. While breathing 100% O2 to ensure a similar arterial O2 content ([Formula: see text]) in both trials, eight male cyclists performed 5-km time trials under control conditions (HCTRL) and with lumbar intrathecal fentanyl (HFENT) impairing neural feedback from the lower limbs. After each time trial, common femoral artery blood flow (FBF) was quantified (Doppler ultrasound) during constant-load cycling performed at the average power of the preceding time trial. The assessment of end-tidal gases, hemoglobin content and saturation, and FBF facilitated the calculation of leg O2 delivery. Locomotor muscle activation during cycling was estimated from vastus lateralis EMG. With electrical femoral nerve stimulation, peripheral and central fatigue were quantified by pre- to postexercise decreases in quadriceps twitch torque (ΔQtw) and voluntary activation (ΔVA), respectively. FBF (~16 mL·min−1·W−1; P = 0.6), [Formula: see text] (~24 mL O2/dL; P = 0.9), and leg O2 delivery (~0.38 mL O2·min−1·W−1; P = 0.9) were not different during HCTRL and HFENT. Mean power output and time to completion were significantly improved by 9% (~310 W vs. ~288 W) and 3% (~479 s vs. ~463 s), respectively, during HFENT compared with HCTRL. Quadriceps muscle activation was 9 ± 7% higher during HFENT compared with HCTRL ( P < 0.05). ΔQtw was significantly greater in HFENT compared with HCTRL (54 ± 8% vs. 39 ± 9%), whereas ΔVA was not different (~5%; P = 0.3) in both trials. These findings reveal that group III/IV muscle afferent feedback limits whole body endurance exercise performance and peripheral fatigue by restricting neural activation of locomotor muscle. NEW & NOTEWORTHY Group III/IV muscle afferent feedback facilitates endurance performance by optimizing locomotor muscle O2 delivery but also limits performance by restricting neural drive to locomotor muscle. To isolate the performance-limiting effect of these sensory neurons, we pharmacologically attenuated their central projection during a cycling time trial while controlling for locomotor muscle O2 delivery. With no difference in leg O2 delivery, afferent blockade attenuated the centrally mediated restriction in motoneuronal output and improved cycling performance.

scholarly journals On the contribution of group III and IV muscle afferents to the circulatory response to rhythmic exercise in humans

2011 ◽  
Vol 589 (15) ◽  
pp. 3855-3866 ◽  
Author(s):  
Markus Amann ◽  
Sean Runnels ◽  
David E. Morgan ◽  
Joel D. Trinity ◽  
Anette S. Fjeldstad ◽  
...  
Keyword(s):  
Muscle Afferents ◽  
Circulatory Response ◽  
Group Iii ◽  
Rhythmic Exercise ◽  
Exercise In Humans

scholarly journals Group III and IV muscle afferents differentially affect the motor cortex and motoneurones in humans

2008 ◽  
Vol 586 (5) ◽  
pp. 1277-1289 ◽  
Author(s):  
P. G. Martin ◽  
N. Weerakkody ◽  
S. C. Gandevia ◽  
J. L. Taylor
Keyword(s):  
Motor Cortex ◽  
Muscle Afferents ◽  
Group Iii
Sign in / Sign up

Export Citation Format

Share Document