ischemic stroke. Several studies have suggested that cerebral hemodynamic impairment is an important pathophysiological mechanism involved in stroke ( Derdeyn, Grubb, & Powers, 1999 ; Salinet, Haunton, Panerai, & Robinson, 2013 ; Silvestrini et al., 2000 ; Yamauchi, 2015 ). The complex interaction
Guohua Zheng, Xin Zheng, Junzhe Li, Tingjin Duan, Kun Ling, Jing Tao and Lidian Chen
Jaqueline P. Batista, Igor M. Mariano, Tállita C.F. Souza, Juliene G. Costa, Jéssica S. Giolo, Nádia C. Cheik, Foued S. Espindola, Sarah Everman and Guilherme M. Puga
indicated as an alternative to physical activity for postmenopausal women ( Fourie et al., 2013 ). In normotensive postmenopausal women, the cardiovascular response after acute mat Pilates exercises performance has not been determined. Therefore, the purpose of this study was to assess the acute hemodynamic
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.
Mark R. Stone, Alan St Clair Gibson and Kevin G. Thompson
Exercise is known to result in hemodynamic changes in the bilateral prefrontal cortex. The aim of this study was to investigate hemodynamic changes in right and left hemispheres of the prefrontal cortex (PFC) during incremental cycling exercise.
After 10 min rest, 9 participants (mean age 26.6 ± 2.5 y, mass 77.5 ± 9.7 kg, stature 1.79 ± 0.9 m) cycled at 100–150 W for 4 min. Thereafter, resistance was increased by 25 W every 4 min until exhaustion (EXH). Respiratory exchange and concentrations of oxy- ([HbO2]), deoxy- ([(HHb]), and total hemoglobin ([Hbtot]) in the PFC were continuously measured. Data were averaged for 60 s at rest and preceding ventilatory threshold 1 (VT1), VT2, and volitional EXH and after 5 min recovery. Subjective ratings of affect were measured at VT1, VT2, VT1 minus 25 W (VT1-25W), and VT2 plus 25 W (VT2+25W).
There were no between-hemispheres differences in [HbO2] or [Hbtot] at rest, VT1, or recovery or in [HHb] at any point. Right-hemisphere [HbO2] and [Hbtot] were significantly greater than left at VT2 (P = .01 and P = .02) and EXH (P = .03 and P = .02). Affect was significantly greater at VT1-25W vs VT2 and VT2+25W and at VT1 and VT2 vs VT2+25W (P < .01–.03).
To the authors’ knowledge, this is the first study to describe an exercise-state-dependent change in PFC asymmetry during incremental exercise. The asymmetry detected coincided with a decrease in affect scores in agreement with the PFC-asymmetry hypothesis.
Hélcio Kanegusuku, Andréia C.C. Queiroz, Valdo J.D. Silva, Marco T. de Mello, Carlos Ugrinowitsch and Cláudia L.M. Forjaz
The effects of high-intensity progressive resistance training (HIPRT) on cardiovascular function and autonomic neural regulation in older adults are unclear. To investigate this issue, 25 older adults were randomly divided into two groups: control (CON, N = 13, 63 ± 4 years; no training) and HIPRT (N = 12, 64 ± 4 years; 2 sessions/week, 7 exercises, 2−4 sets, 10−4 RM). Before and after four months, maximal strength, quadriceps cross-sectional area (QCSA), clinic and ambulatory blood pressures (BP), systemic hemodynamics, and cardiovascular autonomic modulation were measured. Maximal strength and QCSA increased in the HIPRT group and did not change in the CON group. Clinic and ambulatory BP, cardiac output, systemic vascular resistance, stroke volume, heart rate, and cardiac sympathovagal balance did not change in the HIPRT group or the CON group. In conclusion, HIPRT was effective at increasing muscle mass and strength without promoting changes in cardiovascular function or autonomic neural regulation.
Mark S. Sklansky, James M. Pivarnik, E. O’Brian Smith, Jody Morris and J. Timothy Bricker
The effects of exercise training on hemodynamics and on the prevalence of arrhythmias in 11 asymptomatic children following tetralogy of Fallot (TOF) repair were investigated. Training consisted of three 30-min supervised exercise sessions per week for 8 consecutive weeks. Each subject exercised on a cycle ergometer and/or treadmill at 60–80% of measured peak heart rate (HR). Submaximal HR decreased (p < .0016), and maximal treadmill time increased, in every patient (p < .0004). Small decreases occurred in submaximal cardiac output (CO) (p < .094), VO2 (p < .047), and respiratory rate (RR) (p < .053). No significant change occurred in peak HR, peak VO2, or in resting LV end-diastolic dimension or posterior wall thickness. No significant change occurred in atrial or ventricular ectopy. It was concluded that young active children following repair of TOF can demonstrate aerobic training effects with an 8-week exercise program of three 30-minute sessions of moderately intense aerobic activity per week.
Near-infrared spectroscopy (NIRS) presents an appealing option for investigating hemodynamic changes in the cerebral cortex during exercise. This review examines the physical basis of NIRS and the types of available instruments. Emphasis is placed on the physiological interpretation of NIRS signals. Theories from affective neuroscience and exercise psychobiology, including Davidson's prefrontal asymmetry hypothesis, Dietrich's transient hypofrontality hypothesis, and Ekkekakis's dual-mode model, are reviewed, highlighting the potential for designing NIRS-based tests in the context of exercise. Findings from 28 studies involving acute bouts of exercise are summarized. These studies suggest that the oxygenation of the prefrontal cortex increases during mild-to-moderate exercise and decreases during strenuous exercise, possibly proximally to the respiratory compensation threshold. Future studies designed to test hypotheses informed by psychological theories should help elucidate the significance of these changes for such important concepts as cognition, affect, exertion, and central fatigue.
Gavin Tempest and Gaynor Parfitt
Imagery, as a cognitive strategy, can improve affective responses during moderate-intensity exercise. The effects of imagery at higher intensities of exercise have not been examined. Further, the effect of imagery use and activity in the frontal cortex during exercise is unknown. Using a crossover design (imagery and control), activity of the frontal cortex (reflected by changes in cerebral hemodynamics using near-infrared spectroscopy) and affective responses were measured during exercise at intensities 5% above the ventilatory threshold (VT) and the respiratory compensation point (RCP). Results indicated that imagery use influenced activity of the frontal cortex and was associated with a more positive affective response at intensities above VT, but not RCP to exhaustion (p < .05). These findings provide direct neurophysiological evidence of imagery use and activity in the frontal cortex during exercise at intensities above VT that positively impact affective responses.
Michael R.M. McGuigan, Roger Bronks, Robert U. Newton, John C. Graham and David V. Cody
Peripheral arterial disease (PAD) is associated with impaired lower extremity function. This study investigated differences in PAD and control participants and the relationship between lower limb strength and clinical measures of PAD severity. Participants were evaluated by 6-min-walk distance, normal and maximal walking speed over 10 m, isometric plantar-flexion strength, and dynamic dorsi-/plantar-flexion strength. Hemodynamic measures of the lower limbs were recorded at rest and after maximal treadmill testing. PAD participants walked significantly less far during the 6-min walk, and there were large differences in normal and maximal walking speeds. Small to moderate differences were found for isometric plantar-flexion strength. In the diseased legs of the PAD participants, resting systolic hallux photoplethysmography was significantly correlated with isokinetic plantar-flexion strength and onset of claudication pain during the 6-min-walk test. In addition to confirming the documented loss of walking endurance, these data suggest that loss of strength of the plantar flexors is associated with increasing PAD impairment.
Hun-young Park, Sang-seok Nam, Hirofumi Tanaka and Dong-jun Lee
The aim of this study was to investigate hemodynamic, hematological, and immunological responses to prolonged submaximal cycle ergometer exercise at a simulated altitude of 3000 m in pubescent girls.
Ten girls, 12.8 ± 1.0 years old, exercised on a cycle ergometer for 60 min at a work rate corresponding to 50% maximal oxygen consumption measured at sea level, under two environmental conditions; sea level (normoxia) and a simulated 3000 m altitude (normobaric hypoxia).
There were no significant differences in tidal volume, ventilation, oxygen consumption, cardiac output, stroke volume, and heart rate between the two exercise conditions. However, reticulocyte, adrenocorticotropic hormone, and cortisol concentrations increased significantly from pre- to postexercise in the hypoxic environment. Leukocyte and T-cell count increased and B-cell count decreased after exercise under both conditions. There were no significant changes in natural killer cell count.
Our simulated hypoxic environment provided a mild environmental stressor that did not impose a heavy burden on the cardiovascular, hematological, or immunological functions during submaximal exercise in pubescent girls.