Changes in Oxyhemoglobin Concentration in the Prefrontal Cortex and Primary Motor Cortex During Low- and Moderate-Intensity Exercise on a Cycle Ergometer

2017 ◽  
pp. 241-247 ◽  
Author(s):  
Nana Takehara ◽  
Atsuhiro Tsubaki ◽  
Yudai Yamazaki ◽  
Chiaki Kanaya ◽  
Daisuke Sato ◽  
...  
Keyword(s):  
Prefrontal Cortex ◽  
Motor Cortex ◽  
Primary Motor Cortex ◽  
Cycle Ergometer ◽  
Moderate Intensity ◽  
Moderate Intensity Exercise

scholarly journals The effect of breaking up prolonged sitting on paired associative stimulation-induced plasticity

2020 ◽  
Vol 238 (11) ◽  
pp. 2497-2506 ◽  
Author(s):  
E. Bojsen-Møller ◽  
M. M. Ekblom ◽  
O. Tarassova ◽  
D. W. Dunstan ◽  
O. Ekblom
Keyword(s):  
Physical Activity ◽  
Motor Cortex ◽  
Fixed Effects ◽  
Primary Motor Cortex ◽  
Short Interval ◽  
Moderate Intensity ◽  
Middle Aged ◽  
Moderate Intensity Exercise ◽  
Abductor Pollicis Brevis ◽  
Paired Associative Stimulation

Abstract Paired associative stimulation (PAS) can induce plasticity in the motor cortex, as measured by changes in corticospinal excitability (CSE). This effect is attenuated in older and less active individuals. Although a single bout of exercise enhances PAS-induced plasticity in young, physically inactive adults, it is not yet known if physical activity interventions affect PAS-induced neuroplasticity in middle-aged inactive individuals. Sixteen inactive middle-aged office workers participated in a randomized cross-over design investigating how CSE and short-interval intracortical inhibition (SICI) were affected by PAS preceded by 3 h of sitting (SIT), 3 h of sitting interrupted every 30 min by 3 min of frequent short bouts of physical activity (FPA) and 2.5 h of sitting followed by 25 min of moderate-intensity exercise (EXE). Transcranial magnetic stimulation was applied over the primary motor cortex (M1) of the dominant abductor pollicis brevis to induce recruitment curves before and 5 min and 30 min post-PAS. Linear mixed models were used to compare changes in CSE using time and condition as fixed effects and subjects as random effects. There was a main effect of time on CSE and planned within-condition comparisons showed that CSE was significantly increased from baseline to 5 min and 30 min post-PAS, in the FPA condition, with no significant changes in the SIT or EXE conditions. SICI decreased from baseline to 5 min post-PAS, but this was not related to changes in CSE. Our findings suggest that in middle-aged inactive adults, FPAs may promote corticospinal neuroplasticity. Possible mechanisms are discussed.

scholarly journals Frontal and motor cortex oxygenation during maximal exercise in normoxia and hypoxia

2009 ◽  
Vol 106 (4) ◽  
pp. 1153-1158 ◽  
Author(s):  
Andrew W. Subudhi ◽  
Brittany R. Miramon ◽  
Matthew E. Granger ◽  
Robert C. Roach
Keyword(s):  
Motor Cortex ◽  
Near Infrared ◽  
Maximal Exercise ◽  
Acute Hypoxia ◽  
Moderate Intensity ◽  
Chamber Pressure ◽  
Motor Drive ◽  
Maximal Power ◽  
Moderate Intensity Exercise ◽  
Test Order

Reductions in prefrontal oxygenation near maximal exertion may limit exercise performance by impairing executive functions that influence the decision to stop exercising; however, whether deoxygenation also occurs in motor regions that more directly affect central motor drive is unknown. Multichannel near-infrared spectroscopy was used to compare changes in prefrontal, premotor, and motor cortices during exhaustive exercise. Twenty-three subjects performed two sequential, incremental cycle tests (25 W/min ramp) during acute hypoxia [79 Torr inspired Po2 (PiO2)] and normoxia (117 Torr PiO2) in an environmental chamber. Test order was balanced, and subjects were blinded to chamber pressure. In normoxia, bilateral prefrontal oxygenation was maintained during low- and moderate-intensity exercise but dropped 9.0 ± 10.7% (mean ± SD, P < 0.05) before exhaustion (maximal power = 305 ± 52 W). The pattern and magnitude of deoxygenation were similar in prefrontal, premotor, and motor regions ( R2 > 0.94). In hypoxia, prefrontal oxygenation was reduced 11.1 ± 14.3% at rest ( P < 0.01) and fell another 26.5 ± 19.5% ( P < 0.01) at exhaustion (maximal power = 256 ± 38 W, P < 0.01). Correlations between regions were high ( R2 > 0.61), but deoxygenation was greater in prefrontal than premotor and motor regions ( P < 0.05). Prefrontal, premotor, and motor cortex deoxygenation during high-intensity exercise may contribute to an integrative decision to stop exercise. The accelerated rate of cortical deoxygenation in hypoxia may hasten this effect.

scholarly journals Multisynaptic projections from the ventrolateral prefrontal cortex to hand and mouth representations of the monkey primary motor cortex

2013 ◽  
Vol 76 (3) ◽  
pp. 141-149 ◽  
Author(s):  
Shigehiro Miyachi ◽  
Yoshihiro Hirata ◽  
Ken-ichi Inoue ◽  
Xiaofeng Lu ◽  
Atsushi Nambu ◽  
...  
Keyword(s):  
Prefrontal Cortex ◽  
Motor Cortex ◽  
Primary Motor Cortex ◽  
Ventrolateral Prefrontal Cortex

scholarly journals Moderate intensity exercise in hypoxia increases IGF-1 bioavailability and serum irisin in individuals with type 1 diabetes

2020 ◽  
Vol 11 ◽  
pp. 204201882092532 ◽  
Author(s):  
Aleksandra Żebrowska ◽  
Marcin Sikora ◽  
Anna Konarska ◽  
Anna Zwierzchowska ◽  
Tomasz Kamiński ◽  
...  
Keyword(s):  
Type 1 Diabetes ◽  
Serum Levels ◽  
Cycle Ergometer ◽  
Moderate Intensity ◽  
Moderate Intensity Exercise ◽  
Physiological Variables ◽  
Hypoxic Conditions ◽  
Study Results ◽  
Glycaemia Control

Aim: This study aimed to determine the effect of moderate intensity continuous exercise (Ex) and hypoxia (Hyp) on serum brain-derived neurotrophic factor (BDNF), insulin-like growth factor-1 (IGF-1) and its binding protein-3 (IGFBP-3), irisin and cytokines levels in patients with type 1 diabetes (T1D). Methods: A total of 14 individuals with T1D (age: 28.7 ± 7.3 years) and 14 healthy adults (age: 27.1 ± 3.9 years) performed 40-min continuous Ex at moderate intensity (50% lactate threshold) on a cycle ergometer in normoxia (Nor) and Hyp (FiO2 = 15.1%) Biochemical factors, glucose concentrations and physiological variables were measured at rest, immediately and up to 24 h after both Ex protocols. Results: Patients with T1D had significantly lower pre-Ex serum concentrations of BDNF ( p < 0.05, p < 0.01), and total IGF-1 ( p < 0.001, p < 0.05) and significantly higher irisin levels ( p < 0.05, p < 0.01) in Nor and Hyp, compared with healthy subjects. Ex significantly increased in T1D group serum BDNF (in Nor only p < 0.05) and total IGF-1 levels in Nor and Hyp ( p < 0.001 and p < 0.01, respectively). Immediately after Ex in Hyp, freeIGF-1 ( p < 0.05) and irisin levels ( p < 0.001) were significantly higher compared with the levels induced by Ex alone. Free IGF-1 and irisin serum levels remained elevated in 24 h post-Ex in Hyp. In T1D, significant blood glucose (BG) decrease was observed immediately after Ex in Hyp ( p < 0.001) and in 24 h recovery ( p < 0.001) compared with pre-Ex level. Conclusion: The study results suggest that moderate intensity continuous Ex has beneficial effect on BDNF and IGF-1 levels. Ex in hypoxic conditions may be more effective in increasing availability of IGF-1. The alterations in the post-Ex irisin levels and IGF-1 system may be contributing to more effective glycaemia control in patients with T1D.

Peripheral Chemoreflex Drive in Moderate-Intensity Exercise

1996 ◽  
Vol 21 (4) ◽  
pp. 285-300 ◽  
Author(s):  
Claudette M. St. Croix ◽  
David A. Cunningham ◽  
Donald H. Paterson ◽  
John M. Kowalchuk
Keyword(s):  
Peak Level ◽  
Cycle Ergometer ◽  
Open Loop ◽  
Moderate Intensity ◽  
Moderate Intensity Exercise ◽  
Peripheral Chemoreceptor ◽  
Carotid Bodies ◽  
Ergometer Exercise ◽  
End Tidal ◽  
Peripheral Chemoreflex

The purpose of this study was to measure the contribution of the peripheral chemoreceptor (pRc) to [Formula: see text] during the steady-state of moderate-intensity cycle ergometer exercise using continuous hyperoxic suppression of pRc drive, while stabilizing the drive from the central chemoreceptor by clamping end-tidal PCO2 (PETCO2) at the peak level attained during the hyperoxic period of a poikilocapnic ride. In the isocapnic protocol, the PETCO2 was maintained at a constant level by a negative feedback, open loop system. Five subjects completed four repetitions of each of the poikilocapnic and isocapnic protocols. In the poikilocapnic protocol, [Formula: see text] declined following the step into hyperoxia and then began to increase, whereas the decline in [Formula: see text] was maintained in the isocapnic protocol. However, the mean decrease in [Formula: see text] was not significantly different between the poikilocapnic (16.1 ± 5.0%) and isocapnic (14.9 ± 4.4%) protocols. These results suggest that the declining phase of [Formula: see text] is fully complete before the secondary central stimulating actions of hyperoxia on [Formula: see text] and that the pRc contributes about 15% of the drive to breathe in moderate intensity exercise. Key words: ventilatory control, carotid bodies, hyperoxia

Prior heavy-intensity exercise speeds V̇o2 kinetics during moderate-intensity exercise in young adults

2005 ◽  
Vol 98 (4) ◽  
pp. 1371-1378 ◽  
Author(s):  
Brendon J. Gurd ◽  
Barry W. Scheuermann ◽  
Donald H. Paterson ◽  
John M. Kowalchuk
Keyword(s):  
Young Adults ◽  
Lactate Threshold ◽  
Near Infrared ◽  
Linear Regression Analysis ◽  
Cycle Ergometer ◽  
Moderate Intensity ◽  
Moderate Intensity Exercise ◽  
Warm Up ◽  
Total Hemoglobin ◽  
Concentration Changes

The effect of prior heavy-intensity warm-up exercise on subsequent moderate-intensity phase 2 pulmonary O2 uptake kinetics (τV̇o2) was examined in young adults exhibiting relatively fast (FK; τV̇o2 < 30 s; n = 6) and slow (SK; τV̇o2 > 30 s; n = 6) V̇o2 kinetics in moderate-intensity exercise without prior warm up. Subjects performed four repetitions of a moderate (Mod1)-heavy-moderate (Mod2) protocol on a cycle ergometer with work rates corresponding to 80% estimated lactate threshold (moderate intensity) and 50% difference between lactate threshold and peak V̇o2 (heavy intensity); each transition lasted 6 min, and each was preceded by 6 min of cycling at 20 W. V̇o2 and heart rate (HR) were measured breath-by-breath and beat-by-beat, respectively; concentration changes of muscle deoxyhemoglobin (HHb), oxyhemoglobin, and total hemoglobin were measured by near-infrared spectroscopy (Hamamatsu NIRO 300). τV̇o2 was lower ( P < 0.05) in Mod2 than in Mod1 in both FK (20 ± 5 s vs. 26 ± 5 s, respectively) and SK (30 ± 8 s vs. 45 ± 11 s, respectively); linear regression analysis showed a greater “speeding” of V̇o2 kinetics in subjects exhibiting a greater Mod1 τV̇o2. HR, oxyhemoglobin, and total hemoglobin were elevated ( P < 0.05) in Mod2 compared with Mod1. The delay before the increase in HHb was reduced ( P < 0.05) in Mod2, whereas the HHb mean response time was reduced ( P < 0.05) in FK (Mod2, 22 ± 3 s; Mod1, 32 ± 11 s) but not different in SK (Mod2, 36 ± 13 s; Mod1, 34 ± 15 s). We conclude that improved muscle perfusion in Mod2 may have contributed to the faster adaptation of V̇o2, especially in SK; however, a possible role for metabolic inertia in some subjects cannot be overlooked.

scholarly journals Oxygen Cost of Recreational Horse-Riding in Females

2015 ◽  
Vol 12 (6) ◽  
pp. 808-813 ◽  
Author(s):  
Louisa Beale ◽  
Neil S Maxwell ◽  
Oliver R Gibson ◽  
Rosemary Twomey ◽  
Becky Taylor ◽  
...  
Keyword(s):  
Oxygen Consumption ◽  
Cycle Ergometer ◽  
Peak Oxygen Consumption ◽  
Moderate Intensity ◽  
Oxygen Cost ◽  
Metabolic Demand ◽  
Moderate Intensity Exercise ◽  
The Public ◽  
Horse Riding ◽  
Ergometer Exercise

Background:The purpose of this study was to characterize the physiological demands of a riding session comprising different types of recreational horse riding in females.Methods:Sixteen female recreational riders (aged 17 to 54 years) completed an incremental cycle ergometer exercise test to determine peak oxygen consumption (VO2peak) and a 45-minute riding session based upon a British Horse Society Stage 2 riding lesson (including walking, trotting, cantering and work without stirrups). Oxygen consumption (VO2), from which metabolic equivalent (MET) and energy expenditure values were derived, was measured throughout.Results:The mean VO2 requirement for trotting/cantering (18.4 ± 5.1 ml·kg-1·min-1; 52 ± 12% VO2peak; 5.3 ± 1.1 METs) was similar to walking/trotting (17.4 ± 5.1 ml·kg-1·min-1; 48 ± 13% VO2peak; 5.0 ± 1.5 METs) and significantly higher than for work without stirrups (14.2 ± 2.9 ml·kg-1·min-1; 41 ± 12% VO2peak; 4.2 ± 0.8 METs) (P = .001).Conclusion:The oxygen cost of different activities typically performed in a recreational horse riding session meets the criteria for moderate intensity exercise (3-6 METs) in females, and trotting combined with cantering imposes the highest metabolic demand. Regular riding could contribute to the achievement of the public health recommendations for physical activity in this population.

scholarly journals Impact of type 2 diabetes on cardiorespiratory function and exercise performance

2016 ◽  
Author(s):  
Joanie Caron ◽  
Gregory R. duManoir ◽  
Lawrence Labrecque ◽  
Audrey Chouinard ◽  
Annie Ferland ◽  
...  
Keyword(s):  
Type 2 Diabetes ◽  
Exercise Performance ◽  
Ventilatory Threshold ◽  
Exponential Model ◽  
Cycle Ergometer ◽  
Moderate Intensity ◽  
Moderate Intensity Exercise ◽  
Cardiorespiratory Function ◽  
The Impact

AbstractThe aim of this study was to examine the impact of well-controlled uncomplicated type 2 diabetes (T2D) on exercise performance. Six obese sedentary men with T2D and 7 control participants without diabetes matched for age, sex and body mass index were recruited. Anthropometric characteristics, blood samples, resting cardiac and pulmonary functions and maximal oxygen uptake (VO2max) and ventilatory threshold were measured on a first visit. On the four subsequent visits, participants performed step transitions (6 min) of moderate-intensity exercise on an upright cycle ergometer from unloaded pedaling to 80 % of ventilatory threshold. VO2(τVO2) and HR (τHR) kinetics were characterized with a mono-exponential model. VO2max (27.8±4.0 vs. 27.5±5.3 ml kg-1min-1; p=0.95), τVO2(43±6 vs. 43±10 s; p=0.73) and τHR (42±17 vs. 43±13 s; p=0.94) were similar between diabetics and controls respectively. The remaining variables were also similar between groups. These results suggest that well-controlled T2D is not associated with a reduction in VO2max or slower τVO2and τHR.

Intensity Matters: High-intensity Interval Exercise Enhances Motor Cortex Plasticity More Than Moderate Exercise

2019 ◽  
Vol 30 (1) ◽  
pp. 101-112 ◽  
Author(s):  
Sophie C Andrews ◽  
Dylan Curtin ◽  
Ziarih Hawi ◽  
Jaeger Wongtrakun ◽  
Julie C Stout ◽  
...  
Keyword(s):  
Motor Cortex ◽  
High Intensity ◽  
Therapeutic Potential ◽  
Intracortical Inhibition ◽  
High Intensity Exercise ◽  
Moderate Intensity ◽  
Moderate Intensity Exercise ◽  
Exercise Interventions ◽  
Interval Exercise ◽  
High Intensity Interval

Abstract A single bout of cardiovascular exercise can enhance plasticity in human cortex; however, the intensity required for optimal enhancement is debated. We investigated the effect of exercise intensity on motor cortex synaptic plasticity, using transcranial magnetic stimulation. Twenty healthy adults (Mage = 35.10 ± 13.25 years) completed three sessions. Measures of cortico-motor excitability (CME) and inhibition were obtained before and after a 20-min bout of either high-intensity interval exercise, moderate-intensity continuous exercise, or rest, and again after intermittent theta burst stimulation (iTBS). Results showed that high-intensity interval exercise enhanced iTBS plasticity more than rest, evidenced by increased CME and intracortical facilitation, and reduced intracortical inhibition. In comparison, the effect of moderate-intensity exercise was intermediate between high-intensity exercise and rest. Importantly, analysis of each participant’s plasticity response profile indicated that high-intensity exercise increased the likelihood of a facilitatory response to iTBS. We also established that the brain-derived neurotrophic factor Val66Met polymorphism attenuated plasticity responses following high-intensity exercise. These findings suggest that high-intensity interval exercise should be considered not only when planning exercise interventions designed to enhance neuroplasticity, but also to maximize the therapeutic potential of non-invasive brain stimulation. Additionally, genetic profiling may enhance efficacy of exercise interventions for brain health.

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