scholarly journals Effects of aerobic exercise under different thermal conditions on human somatosensory processing

2016 ◽  
Vol 311 (4) ◽  
pp. R629-R636 ◽  
Author(s):  
Hiroki Nakata ◽  
Misaki Oshiro ◽  
Mari Namba ◽  
Manabu Shibasaki
Keyword(s):  
Aerobic Exercise ◽  
Rest Period ◽  
Thermal Conditions ◽  
Exercise Bout ◽  
Somatosensory Processing ◽  
Posterior Tibial Nerve Stimulation ◽  
Mean Power ◽  
Somatosensory Input ◽  
Before And After ◽  
Mean Power Output

The present study aimed to investigate the effects of aerobic exercise on human somatosensory processing recorded by somatosensory evoked potentials (SEPs) under temperate [TEMP, 20°C and 40% relative humidity (RH)] and hot (HOT, 35°C and 30% RH) environments. Fifteen healthy subjects performed 4 × 15-min bouts of a moderate cycling exercise [mean power output: 156.5 ± 7.7 (SE) W], with a 10-min rest period and received a posterior tibial nerve stimulation at the left ankle before and after each exercise bout; SEPs were recorded in five sessions; 1st (pre), 2nd (post-1st exercise bout), 3rd (post-2nd exercise bout), 4th (post-3rd exercise bout), and 5th (post-4th exercise bout). The peak latencies and amplitudes of the P37, N50, P60, and N70 components at Cz were evaluated. The latencies of P37, N50, P60, and N70 were significantly shorter with the repetition of aerobic exercise, and these shortened latencies were significantly greater in the HOT condition than in the TEMP condition (P37: 3rd, P < 0.05, and 5th, P < 0.01; P60: 4th, P < 0.05, and 5th, P < 0.01; N70: 4th, P < 0.05, and 5th, P < 0.001). No significant differences were observed in the amplitudes of any SEP component under either thermal condition. These results suggest that the conduction velocity of the ascending somatosensory input was accelerated by increases in body temperature, and aerobic exercise did not alter the strength of neural activity in cortical somatosensory processing.

scholarly journals Effects of passive heat stress on human somatosensory processing

2015 ◽  
Vol 309 (11) ◽  
pp. R1387-R1396 ◽  
Author(s):  
Hiroki Nakata ◽  
Misaki Oshiro ◽  
Mari Namba ◽  
Manabu Shibasaki
Keyword(s):  
Heat Stress ◽  
Body Temperature ◽  
Stress Condition ◽  
Thermal Conditions ◽  
Somatosensory Processing ◽  
Left Wrist ◽  
Time Control ◽  
Median Nerve Stimulation ◽  
Somatosensory Input ◽  
Heat Stress Condition

Herein, we investigated the effects of passive heat stress on human somatosensory processing recorded by somatosensory-evoked potentials (SEPs). Fifteen healthy subjects received a median nerve stimulation at the left wrist under two thermal conditions: Heat Stress and normothermic Time Control. The latencies and amplitudes of P14, N20, P25, N35, P45, and N60 at C4′ and P14, N18, P22, and N30 at Fz were evaluated. Under the Heat Stress condition, SEPs were recorded at normothermic baseline (1st), early in heat stress (2nd), when esophageal temperature had increased by ∼1.0°C (3rd) and ∼2.0°C (4th), and after heat stress (5th). In the Time Control condition, SEPs were measured at the same time intervals as those in the Heat Stress condition. The peak latencies and amplitudes of SEPs did not change early in heat stress. However, the latencies of P14, N20, and N60 at C4′ and P14, N18, and P22 at Fz were significantly shorter in the 4th session than in the 1st session. Furthermore, the peak amplitudes of P25 and N60 at C4′, and P22 and N30 at Fz decreased with increases in body temperature. On the other hand, under the Time Control condition, no significant differences were observed in the amplitudes or latencies of any component of SEPs. These results suggested that the conduction velocity of the ascending somatosensory input was accelerated by increases in body temperature, and hyperthermia impaired the neural activity of cortical somatosensory processing.

Effect of training on muscle metabolism during treadmill sprinting

1989 ◽  
Vol 67 (6) ◽  
pp. 2376-2382 ◽  
Author(s):  
M. E. Nevill ◽  
L. H. Boobis ◽  
S. Brooks ◽  
C. Williams
Keyword(s):  
Vastus Lateralis ◽  
Muscle Metabolism ◽  
Plasma Norepinephrine ◽  
Sprint Training ◽  
Mean Power ◽  
Muscle Lactate ◽  
Group 4 ◽  
Before And After ◽  
Muscle Buffering Capacity ◽  
Mean Power Output

Sixteen subjects volunteered for the study and were divided into a control (4 males and 4 females) and experimental group (4 males and 4 females, who undertook 8 wk of sprint training). All subjects completed a maximal 30-s sprint on a nonmotorized treadmill and a 2-min run on a motorized treadmill at a speed designed to elicit 110% of maximum oxygen uptake (110% run) before and after the period of training. Muscle biopsies were taken from vastus lateralis at rest and immediately after exercise. The metabolic responses to the 110% run were unchanged over the 8-wk period. However, sprint training resulted in a 12% (P less than 0.05) and 6% (NS) improvement in peak and mean power output, respectively, during the 30-s sprint test. This improvement in sprint performance was accompanied by an increase in the postexercise muscle lactate (86.0 +/- 26.4 vs. 103.6 +/- 24.6 mmol/kg dry wt, P less than 0.05) and plasma norepinephrine concentrations (10.4 +/- 5.4 vs. 12.1 +/- 5.3 nmol/l, P less than 0.05) and by a decrease in the postexercise blood pH (7.17 +/- 0.11 vs. 7.09 +/- 0.11, P less than 0.05). There was, however, no change in skeletal muscle buffering capacity as measured by the homogenate technique (67.6 +/- 6.5 vs. 71.2 +/- 4.5 Slykes, NS).

scholarly journals The Effects of Plyometric Conditioning Exercises on Volleyball Performance with Self-Selected Rest Intervals

2021 ◽  
Vol 11 (18) ◽  
pp. 8329
Author(s):  
Michal Krzysztofik ◽  
Rafal Kalinowski ◽  
Aleksandra Filip-Stachnik ◽  
Michal Wilk ◽  
Adam Zajac
Keyword(s):  
Performance Enhancement ◽  
Lower Body ◽  
Mean Power ◽  
Back Squat ◽  
Specific Performance ◽  
Volleyball Players ◽  
Before And After ◽  
Ball Velocity ◽  
Mean Power Output ◽  
Rest Intervals

Post-activation performance enhancement remains a topic of debate in sport science. The purpose of this study was to examine the effects of lower-body plyometric conditioning activity (CA) with a self-selected intra-complex rest interval on upper and lower-body volleyball specific performance. Eleven resistance-trained female volleyball players participated in the study (age: 20 ± 2 years; body mass: 67.8 ± 4.4 kg; height: 178 ± 6 cm; half back squat one-repetition maximum: 78.6 ± 10.2 kg; experience in resistance training: 5.5 ± 2.1 years and in volleyball training: 10 ± 2.3 years). Each participant performed a plyometric CA followed by two different sport-specific tests: an attack jump and a standing spike attack. The changes in jump height (JH), relative mean power output (MP) and ball velocity (BV) were analyzed before and after the CA with self-selected rest intervals. The applied plyometric CA with self-selected intra-complex rest intervals led to an insignificant decline in JH (p = 0.594; effect size [ES]: −0.27) and MP (p = 0.328; ES: −0.46) obtained during the attack jump as well as a significant decline in BV (p = 0.029; ES: −0.72) during the standing spike attack. This study showed that a plyometric CA with self-selected intra-complex rest intervals failed to elicit localized and non-localized PAPE effect in a group of sub-elite volleyball players.

scholarly journals The influence of the ACTN3 R577X polymorphism in the responsiveness to post-activation jump performance enhancement in untrained young men

2021 ◽  
Vol 23 ◽  
Author(s):  
Guilherme Beneduzzi Mantovani ◽  
Renan Vieira Barreto ◽  
Victor Alvino de Souza ◽  
Carlos Roberto Bueno Júnior ◽  
Claudio de Oliveira Assumpção ◽  
...  
Keyword(s):  
Gene Polymorphisms ◽  
Performance Enhancement ◽  
Effect Sizes ◽  
Vertical Force ◽  
Mean Power ◽  
Jump Performance ◽  
Significance Level ◽  
Repetition Maximum ◽  
Before And After ◽  
Mean Power Output

ABSTRACT We aimed to investigate the influence of alpha-actinin-3 (ACTN3) R577X polymorphism on responsiveness to post-activation performance enhancement (PAPE) of countermovement jumps (CMJ) in untrained subjects. Sixteen untrained men were allocated into two groups according to their ACTN3 gene alleles: homozygous for the X allele (XX, n = 9) or homozygous for the R allele (RR, n = 7). CMJ height, mean power output and vertical force were determined twice (CMJ1 and CMJ2) in two conditions: control (CON) and potentiated (PAPE). In the CON condition, CMJ were performed before and after a 15-min rest. In the PAPE condition, CMJ were performed 15 min before and 4 min following five squats with a 5-repetition maximum (5RM) load. Different conditions were applied on separate days in a randomized order. Statistical analysis involved three-way ANOVAs to compare the differences between conditions (CON and PAPE), time (CMJ1 and CMJ2), and groups (XX and RR). Significance level considered was p < 0.05. Effect sizes were calculated as Cohen’s d. The effect sizes for changes in CMJ height for CON and following pre-activation for PAPE were 0.04 and 0.08, respectively. No significant differences were found for CMJ height between XX and RR at baseline (1.07 ± 2.54 cm e -0.82 ± 2.56 cm, respectively). No differences were found (p>0.05) in responsiveness to PAPE between the groups (XX = -0.20 ± 1.6 cm and RR = -0.81 ± 2.7 cm). We conclude that ACTN3 gene polymorphisms does not influence responsiveness to PAPE.

Micronutrient Fortified Carbohydrate Supplementation and Speed, Agility and Power in Indian Adolescent Athletes

2017 ◽  
Vol 54 (1) ◽  
pp. 1
Author(s):  
Tessa E. Morris ◽  
Rachana Bhoite ◽  
Ritu Karwal ◽  
, Verma ◽  
, Bhavna ◽  
...  
Keyword(s):  
Intermittent Exercise ◽  
Cycle Ergometer ◽  
Adolescent Athletes ◽  
Mean Power ◽  
Wingate Anaerobic Test ◽  
Performance Impact ◽  
Treatment Groups ◽  
Before And After ◽  
The Difference ◽  
Mean Power Output

The positive performance impact of exogenous carbohydrate intake on prolonged endurance is well established. The effect on shorter duration activities has been less documented, in particular with adolescents. In this randomized, cross over study, thirty adolescent athletes (24 male and 6 female; age: 13.5 ± 1.0 yrs; height: 161.4 ± 8.1cm; weight: 50.4 ± 9.3 kg) performed the same sequence of procedures; baseline assessments, a treatment drink before and after a 45 min intermittent exercise protocol followed by post-baseline assessments. Participants were randomised to one of three blinded treatment drinks; micronutrient fortified carbohydrate (CHO), calorie-matched control (PRO) or water (WAT). The assessments involved repeated sprint and repeated agility tests (6 repetitions; 65 sec. provided to complete the repetition and recover prior to the next effort) and a repeated Wingate anaerobic test (3 x 30 sec) on a cycle ergometer. The Fatigue Index (FI) was calculated from the sprint and agility results and Mean Power Output (MPO) from the repeated Wingate results. The difference between the baseline and post-baseline results was then calculated and CHO, PRO and WAT treatment groups compared using Analysis of variance (ANOVA). No significant differences were found between speed, agility and power change from baseline results when CHO, PRO and WAT treatment groups were compared (p ≥ 0.05). Supplementation with a micronutrient fortified carbohydrate beverage does not increase repeated speed, agility or power in Indian adolescent team sport athletes.

scholarly journals Acute Exercise Increases Adiponectin Levels in Abdominally Obese Men

2012 ◽  
Vol 2012 ◽  
pp. 1-6 ◽  
Author(s):  
Travis J. Saunders ◽  
Andrew Palombella ◽  
K. Ashlee McGuire ◽  
Peter M. Janiszewski ◽  
Jean-Pierre Després ◽  
...  
Keyword(s):  
Aerobic Exercise ◽  
Acute Exercise ◽  
Treadmill Exercise ◽  
Aerobic Exercise Training ◽  
Exercise Session ◽  
Short Term ◽  
Acute Bout ◽  
Plasma Adiponectin ◽  
Peak Intensity ◽  
Before And After

Objective. To examine the effect of acute and short-term (~1 week) aerobic exercise training on plasma adiponectin levels in inactive, abdominally obese men.Materials and Methods. Inactive and abdominally obese men (n=38, waist circumference ≥102 cm) recruited from Kingston, Canada were randomly allocated to perform three bouts of aerobic treadmill exercise at either low (50% VO2peak) or high (75% VO2peak) intensity during a 1-week period. Blood samples were taken before and after the first exercise session and 24–72 hours following the completion of the final exercise session.Results. Adiponectin levels were elevated immediately following an acute bout of exercise at both high and low intensities (High:5.79±0.42versus5.05±0.41 ug/mL; Low:5.24±0.44versus4.37±0.44 ug/mL,P<0.05) and remained elevated following 30 minutes of rest. In comparison to baseline, adiponectin levels were also elevated 24–72 hours following the final exercise session (High:5.47±0.48versus4.88±0.48 ug/mL; Low:5.18±0.49versus4.47±0.49 ug/mL,P<0.05).Conclusion. Both acute and short-term aerobic exercise result in a significant increase in plasma adiponectin levels in inactive, abdominally obese men independent of intensity.

IMCL area density, but not IMCL utilization, is higher in women during moderate-intensity endurance exercise, compared with men

2007 ◽  
Vol 293 (6) ◽  
pp. R2336-R2342 ◽  
Author(s):  
Michaela C. Devries ◽  
Stuart A. Lowther ◽  
Alexander W. Glover ◽  
Mazen J. Hamadeh ◽  
Mark A. Tarnopolsky
Keyword(s):  
Lipid Oxidation ◽  
Endurance Exercise ◽  
Oxidation Rate ◽  
Respiratory Exchange Ratio ◽  
Exercise Bout ◽  
Moderate Intensity ◽  
Intramyocellular Lipid ◽  
Area Density ◽  
Net Use ◽  
Before And After

Women use more fat during endurance exercise as evidenced by a lower respiratory exchange ratio (RER). The contribution of intramyocellular lipid (IMCL) to lipid oxidation during endurance exercise is controversial, and studies investigating sex differences in IMCL utilization have found conflicting results. We determined the effect of sex on net IMCL use during an endurance exercise bout using an ultrastructural evaluation. Men ( n = 17) and women ( n = 19) completed 90-min cycling at 63% V̇o2peak. Biopsies were taken before and after exercise and fixed for electron microscopy to determine IMCL size, # IMCL/area, IMCL area density, and the % IMCL touching mitochondria. Women had a lower RER and carbohydrate oxidation rate and a higher lipid oxidation rate during exercise ( P < 0.05), compared with men. Women had a higher # IMCL/area and IMCL area density ( P < 0.05), compared with men. Women, but not men, had a higher % IMCL touching mitochondria postexercise ( P = 0.03). Exercise decreased IMCL area density ( P = 0.01), due to a decrease in the # IMCL/area ( P = 0.02). There was no sex difference in IMCL size or net use. In conclusion, women have higher IMCL area density compared with men, due to an increased # IMCL and not an increased IMCL size, as well as an increased % IMCL touching mitochondria postexercise. Endurance exercise resulted in a net decrease in IMCL density due to decreased number of IMCL, not decreased IMCL size, in both sexes.

scholarly journals Resistance and aerobic exercise protects against acute endothelial impairment induced by a single exposure to hypertension during exertion

2011 ◽  
Vol 110 (4) ◽  
pp. 1013-1020 ◽  
Author(s):  
Shane A. Phillips ◽  
Emon Das ◽  
Jingli Wang ◽  
Kirkwood Pritchard ◽  
David D. Gutterman
Keyword(s):  
Blood Pressure ◽  
Resistance Exercise ◽  
Aerobic Exercise ◽  
Vascular Function ◽  
Cardiovascular Health ◽  
Weight Lifting ◽  
Acute Hypertension ◽  
Before And After ◽  
Weight Lifters ◽  
Blood Pressure Responses

Resistance and aerobic exercise is recommended for cardiovascular health and disease prevention. However, the accompanying increase in arterial pressure during resistance exercise may be detrimental to vascular health. This study tests the vascular benefits of aerobic compared with resistance exercise on preventing impaired vascular function induced by a single weight lifting session that is associated with acute hypertension. Healthy, lean sedentary (SED) subjects, weight lifters, runners (>15 miles/wk), and cross trainers (chronic aerobic and resistance exercisers), underwent a single progressive leg press weight lifting session with blood pressure measurements. Brachial artery flow-mediated vasodilation (FMD; an index of arterial endothelial function) was determined using ultrasonography immediately before and after weight lifting. Sublingual nitroglycerin (0.4 mg) was used to determine endothelium-independent dilation after weight lifting. All subjects were normotensive with similar blood pressure responses during exercise. Baseline FMD was lower in runners (5.4 ± 0.5%; n = 13) and cross trainers (4.44 ± 0.3%; n = 13) vs. SED (8.5 ± 0.8%; n = 13; P = 0.037). Brachial FMD improved in conditioned weight lifters (to 8.8 ± 0.9%; P = 0.007) and runners (to 7.6 ± 0.6%; P < 0.001) but not cross trainers (to 5.3 ± 0.6%; P = NS) after acute hypertension. FMD was decreased in SED (to 5.7 ± 0.4%; P = 0.019). Dilation to nitroglycerin was similar among groups. These data suggest that endothelial responses are maintained after exposure to a single bout of weight lifting in resistance and aerobic athletes. Resistance and aerobic exercise may confer similar protection against acute vascular insults such as exertional hypertension.

Mechanical effects of obesity on airway responsiveness in otherwise healthy humans

2009 ◽  
Vol 107 (2) ◽  
pp. 408-416 ◽  
Author(s):  
Roberto Torchio ◽  
Alessandro Gobbi ◽  
Carlo Gulotta ◽  
Raffaele Dellacà ◽  
Marco Tinivella ◽  
...  
Keyword(s):  
Body Mass Index ◽  
Lung Function ◽  
Body Mass ◽  
Airway Hyperresponsiveness ◽  
Healthy Subjects ◽  
Rest Period ◽  
Healthy Humans ◽  
Before And After ◽  
Maximum Expiratory Flow ◽  
Residual Capacity

We investigated whether obesity is associated with airway hyperresponsiveness in otherwise healthy humans and, if so, whether this correlates with a restrictive lung function pattern or a decreased number of sighs at rest and/or during walking. Lung function was studied before and after inhaling methacholine (MCh) in 41 healthy subjects with body mass index ranging from 20 to 56. Breathing pattern was assessed during a 60-min rest period and a 30-min walk. The dose of MCh that produced a 50% decrease in the maximum expiratory flow measured in a body plethysmograph (PD50MCh) was inversely correlated with body mass index ( r2 = 0.32, P < 0.001) and waist circumference ( r2 = 0.25, P < 0.001). Significant correlations with body mass index were also found with the maximum changes in respiratory resistance ( r2 = 0.19, P < 0.001) and reactance ( r2 = 0.40, P < 0.001) measured at 5 Hz. PD50MCh was also positively correlated with functional residual capacity ( r2 = 0.56, P < 0.001) and total lung capacity ( r2 = 0.59, P < 0.001) in men, but not in women. Neither PD50MCh nor body mass index correlated with number of sighs, average tidal volume, ventilation, or breathing frequency. In this study, airway hyperresponsiveness was significantly associated with obesity in otherwise healthy subjects. In obese men, but not in women, airway hyperresponsiveness was associated with the decreases in lung volumes.

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