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Luca Pollonini, Lauren Gulley Cox, and Stacey L. Gorniak

changes, alterations in motor unit structure and function, and reduced hemodynamic function, as underlying mechanisms for these motor changes. Due to the confluence of multiple systemic changes in persons with DM, the contribution of impaired systems, beyond tactile dysfunction, to motor dysfunction prior

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Bianca Fernandes, Fabio Augusto Barbieri, Fernanda Zane Arthuso, Fabiana Araújo Silva, Gabriel Felipe Moretto, Luis Felipe Itikawa Imaizumi, Awassi Yophiwa Ngomane, Guilherme Veiga Guimarães, and Emmanuel Gomes Ciolac

cardiovascular autonomic function (ie, reduced heart rate variability [HRV], impaired hemodynamic response to postural challenges, and altered circadian blood pressure [BP] rhythm) 4 – 8 is an important nonmotor impairment in individuals with PD. It is well known that cardiovascular autonomic dysfunction is

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Darryn S. Willoughby, Tony Boucher, Jeremy Reid, Garson Skelton, and Mandy Clark

Background:

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.

Methods:

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).

Results:

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).

Conclusion:

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.

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Guohua Zheng, Xin Zheng, Junzhe Li, Tingjin Duan, Kun Ling, Jing Tao, and Lidian Chen

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

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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

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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.

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Mark R. Stone, Alan St Clair Gibson, and Kevin G. Thompson

Purpose:

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.

Methods:

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).

Results:

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).

Conclusions:

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.

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Panteleimon Ekkekakis

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.

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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.

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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.