Influence of muscular contraction on vascular conductance during exercise above versus below critical power

2021 ◽  
pp. 103718
Author(s):  
Shane M. Hammer ◽  
Stephen T. Hammond ◽  
Shannon K. Parr ◽  
Andrew M. Alexander ◽  
Vanessa-Rose G. Turpin ◽  
...  
Keyword(s):  
Critical Power ◽  
Muscular Contraction ◽  
Vascular Conductance

scholarly journals The Effects of 15 or 30 s SIT in Normobaric Hypoxia on Aerobic, Anaerobic Performance and Critical Power

2021 ◽  
Vol 18 (8) ◽  
pp. 3976
Author(s):  
Hakan Karabiyik ◽  
Mustafa Can Eser ◽  
Ozkan Guler ◽  
Burak Caglar Yasli ◽  
Goktug Ertetik ◽  
...  
Keyword(s):  
Critical Power ◽  
Interval Training ◽  
Normobaric Hypoxia ◽  
Time To Exhaustion ◽  
Anaerobic Performance ◽  
Sprint Interval Training ◽  
Mean Power ◽  
Training Adaptations ◽  
Post Test

Sprint interval training (SIT) is a concept that has been shown to enhance aerobic-anaerobic training adaptations and induce larger effects in hypoxia. The purpose of this study was to examine the effects of 4 weeks of SIT with 15 or 30 s in hypoxia on aerobic, anaerobic performance and critical power (CP). A total of 32 male team players were divided into four groups: SIT with 15 s at FiO2: 0.209 (15 N); FiO2: 0.135 (15 H); SIT with 30 s at FiO2: 0.209 (30 N); and FiO2: 0.135 (30 H). VO2max did not significantly increase, however time-to-exhaustion (TTE) was found to be significantly longer in the post test compared to pre test (p = 0.001) with no difference between groups (p = 0.86). Mean power (MPw.kg) after repeated wingate tests was significantly higher compared to pre training in all groups (p = 0.001) with no difference between groups (p = 0.66). Similarly, CP was increased in all groups with 4 weeks of SIT (p = 0.001) with no difference between groups (p = 0.82). This study showed that 4 weeks of SIT with 15 and 30 s sprint bouts in normoxia or hypoxia did not increased VO2max in trained athletes. However, anerobic performance and CP can be increased with 4 weeks of SIT both in normoxia or hypoxia with 15 or 30 s of sprint durations.

scholarly journals Determining the Optimal Workrate for Cycle Ergometer Verification Phase Testing in Males with Obesity

Sports ◽  
2021 ◽  
Vol 9 (2) ◽  
pp. 30
Author(s):  
Jenny M. Mahoney ◽  
Brett R. Baughman ◽  
Ailish C. Sheard ◽  
Brandon J. Sawyer
Keyword(s):  
Body Mass Index ◽  
Young Adult ◽  
Body Mass ◽  
Critical Power ◽  
Cycle Ergometer ◽  
Adult Males ◽  
Ramp Test ◽  
Young Adult Males ◽  
Main Effect ◽  
Vo2max Test

The aim of the present study was to assess the validity of verification phase (VP) testing and a 3 min all-out test to determine critical power (CP) in males with obesity. Nine young adult males with a body mass index (BMI) ≥ 30 kg·m−2 completed a cycle ergometer ramp-style VO2max test, four randomized VP tests at 80, 90, 100, and 105% of maximum wattage attained during the ramp test, and a 3 min all-out test. There was a significant main effect for VO2max across all five tests (p = 0.049). Individually, 8 of 9 participants attained a higher VO2max (L/min) during a VP test compared to the ramp test. A trend (p = 0.06) was observed for VO2max during the 90% VP test (3.61 ± 0.54 L/min) when compared to the ramp test (3.37 ± 0.39 L/min). A significantly higher VO2max (p = 0.016) was found in the VP tests that occurred below 130% of CP wattage (N = 15, VO2max = 3.76 ± 0.52 L/min) compared to those that were above (N = 21, VO2max = 3.36 ± 0.41 L/min). Our findings suggest submaximal VP tests at 90% may elicit the highest VO2max in males with obesity and there may be merit in using % of CP wattage to determine optimal VP intensity.

scholarly journals In vitro and in vivo applications of Euphorbia wallichii shoot extract-mediated gold nanospheres

2021 ◽  
Vol 10 (1) ◽  
pp. 101-111
Author(s):  
Rehman Ullah ◽  
Sumaira Shah ◽  
Zahir Muhammad ◽  
Sajjad Ali Shah ◽  
Shah Faisal ◽  
...  
Keyword(s):  
Gold Nanoparticles ◽  
Muscular Contraction ◽  
Surface Plasmon Resonance Peak ◽  
Plasmon Resonance Peak ◽  
Optical Absorption Peak ◽  
Visible Spectra ◽  
Scattering Spectra ◽  
Dose Dependent

Abstract The current study was designed to investigate the potential of Euphorbia wallichii shoot extract for reducting Au3+ and stabilizing gold nanoparticles. UV-visible spectra of gold nanoparticles showed obvious surface plasmon resonance peak at 548 nm. Microscopy (SEM and TEM) showed spherical dimensions, and the energy dispersive X-ray spectra displayed the strongest optical absorption peak for gold (Au) at 2.1 keV. Dynamic light scattering spectra represent polydispersed mixture with particulate diameter of 2.5–103.2 nm. The IR spectra confirm the potential functional groups of shoot extract responsible for the reduction of Au3+ to gold nanoparticles which exhibit tremendous antibacterial potential of 76.31%, 68.47%, 79.85%, 48.10%, and 65.53% against Escherichia coli, Staphylococcus aureus, Bacillus pumilus, Pseudomonas aeruginosa, and Klebsiella pneumoniae, respectively. Gold nanoparticles showed markedly elevated fungicidal potency compared to the shoot extract alone against the tested fungal strains. IC50 for 2,2-diphenyl-1-picrylhydrazyl scavenging was 31.52, 18.29, and 15.32 µg/mL at 30, 60, and 90 min of reaction time, respectively. Both shoot extract and nanoparticles revealed 71% mortality at 100 µg/mL, with LD90 values of 310.56 µg/mL. Experimental mice acquired dose-dependent analgesia of 54.21%, 82.60%, and 86.53% when treated with gold nanoparticles at 50, 100, and 200 mg/kg bw. Inhibition of gastrointestinal muscular contraction was 21.16%, 30.49%, and 40.19% in mice feed with 50, 100, and 200 mg/kg bw, respectively.

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