exercise training ( 14 ). The rise in blood flow to the active muscle at the onset of exercise increases shear stress, causing endothelium-dependent vasodilation ( 37 ). Shear stress, the functional force exerted by blood flow on the vessel wall, can be inferred from Doppler assessment of vessel wall shear
Ali M. McManus, Nathan R. Sletten and Daniel J. Green
Darryn S. Willoughby, Tony Boucher, Jeremy Reid, Garson Skelton and Mandy Clark
Arginine-alpha-ketoglutarate (AAKG) supplements are alleged to increase nitric oxide production, thereby resulting in vasodilation during resistance exercise. This study sought to determine the effects of AAKG supplementation on hemodynamics and brachial-artery blood flow and the circulating levels of L-arginine, nitric oxide metabolites (NOx; nitrate/nitrite), asymmetric dimethyl arginine (ADMA), and L-arginine:ADMA ratio after resistance exercise.
Twenty-four physically active men underwent 7 days of AAKG supplementation with 12 g/day of either NO2 Platinum or placebo (PLC). Before and after supplementation, a resistance-exercise session involving the elbow flexors was performed involving 3 sets of 15 repetitions with 70–75% of 1-repetition maximum. Data were collected immediately before, immediately after (PST), and 30 min after (30PST) each exercise session. Data were analyzed with factorial ANOVA (p < .05).
Heart rate, blood pressure, and blood flow were increased in both groups at PST (p = .001) but not different between groups. Plasma L-arginine was increased in the NO2 group (p = .001). NOx was shown to increase in both groups at PST (p = .001) and at 30PST (p = .001) but was not different between groups. ADMA was not affected between tests (p = .26) or time points (p = .31); however, the L-arginine:ADMA ratio was increased in the NO2 group (p = .03).
NO2 Platinum increased plasma L-arginine levels; however, the effects observed in hemodynamics, brachial-artery blood flow, and NOx can only be attributed to the resistance exercise.
Austin T. Robinson, Adriana Mazzuco, Ahmad S. Sabbahi, Audrey Borghi-Silva and Shane A. Phillips
Falls, NY ). All BP measurements were taken in triplicate with 1-min intervals between measures. The average of the three values was recorded. Flow-mediated vasodilation FMD was assessed using ultrasonography (Prosound Alpha 7; Hitachi Aloka, Chiyoda, Tokyo, Japan). A rapid-release cuff (D. E. Hokanson
Matthew David Cook and Mark Elisabeth Theodorus Willems
of the blackcurrant studies with short-duration exercise periods of Cook et al. ( 2015 ), Murphy et al. ( 2017 ), Perkins et al. ( 2015 ), and Willems et al. ( 2016 ). Anthocyanins have been shown to increase vasodilation and cardiac output ( Cook et al., 2017b ) and peripheral blood flow in the
Gustavo Monnerat, Alex S. Maior, Marcio Tannure, Lia K.F.C. Back and Caleb G.M. Santos
Classical twin studies that presented heritability rates associated with performance in various sports disciplines support the value of genetics in determining the response. In addition, numerous trials involving physiological responses such as hypertrophy, energy expenditure, vasodilation, cardiac output
Lee N. Burkett, Jack Chisum, Jack Pierce, Kent Pomeroy, Jim Fisher and Margie Martin
Twenty spinal-cord-injured subjects (4 quadriplegics and 16 paraplegics) were maximally stress tested on the Arizona State University wheelchair ergometer. Physiological data for each individual were collected as follows: (a) blood flow in the left leg by a photoelectric plethysmograph before exercise, during exercise, and postexercise, and (b) blood lactates before exercise and post-exercise. Eleven subjects had increased leg blood flow and vasodilation during exercise, but vasoconstriction postexercise. The lactate readings, in comparison to able-bodied individuals, were higher at rest but lower at maximal exercise.
Rose M. Giordano, John W. Newman, Theresa L. Pedersen, Marisa I. Ramos and Charles L. Stebbins
Metabolites of the cytochrome P450 (CYP) pathway may contribute to vasodilation of the vasculature. However, it is not known whether exercise affects their circulating concentrations. The authors determined effects of exercise intensity and duration on plasma concentrations of epoxy and dihydroxy metabolites of arachidonic acid. Their goal was to delineate the threshold workload, optimal workload, and duration required to produce increases in plasma concentrations of these vasoactive substances. Healthy volunteers (N = 14) performed maximal exercise testing on a bicycle ergometer during Visit 1. On separate days, subjects cycled for 20 min at 30%, 60%, and 80% of their maximal exercise intensity. The last day consisted of 40 min of exercise at 60% of maximal exercise intensity. Venous blood was obtained before, during, and after exercise for analysis. Compared with rest, increases were observed during the 80% workload at 20 min postexercise —14,15-DHET (0.77 ± 0.21 vs. 0.93 ± 0.27 nM)—and at 2 min postexercise: 11,12-DHET (0.64 ± 0.22 vs. 0.71 ± 0.24 nM; p < .05). Also compared with rest, 40-min values during the 60% workload were 14,15-DHET 0.79 ± 0.22 vs. 0.91 ± 0.31 nM and at 2 min post 14,15 EET 0.12 ± 0.06 vs. 0.21 ± 0.16 nM (p < .05). Results suggest the CYP metabolites (i.e., DHETs) are released during short-term high-intensity and long-term moderateintensity exercise.
Joaquin U. Gonzales, Dustin M. Grinnell, Martha J. Kalasky and David N. Proctor
The authors examined interindividual and sex-specific variation in systolic (SBP) and diastolic (DBP) blood pressure responses to graded leg-extension exercise in healthy older (60–78 yr) women (n = 21) and men (n = 19). Maximal oxygen uptake (VO2max), body composition, physical activity (accelerometry), and vascular function were measured to identify predictors of exercise BP. Neither VO2max nor activity counts were associated with the rise in SBP or DBP during exercise in men. The strongest predictors of these responses in men were age (SBP: r 2 = .19, p = .05) and peak exercise leg vasodilation (DBP: r 2 = –.21, p < .05). In women, the modest relationship observed between VO2max and exercise BP was abolished after adjusting for central adiposity and activity counts (best predictors, cumulative r 2 = .53, p < .05, for both SBP and DBP). These results suggest that determinants of variation in submaximal exercise BP responses among older adults are sex specific, with daily physical activity influencing these responses in women but not men.
following except : a. increased core temperature b. increased heart rate c. increased stroke volume d. peripheral vasodilation 3. There is moderate evidence suggesting cold water immersion as a precooling intervention improves endurance performance in cyclists and runners in a hot, humid environment. a
Saowaluck Suntraluck, Hirofumi Tanaka and Daroonwan Suksom
, 2004 ). Vascular dysfunction plays an important role in the pathogenesis of diabetic vascular disease, which is characterized by reduced endothelium-dependent vasodilation ( Roberts & Porter, 2013 ) and stiffening of central arteries ( Aso et al., 2003 ). Indeed, flow-mediated dilation (FMD), a