Sympathetic outflow to the skeletal muscle in humans increases during prolonged light exercise

1997 ◽  
Vol 82 (4) ◽  
pp. 1237-1243 ◽  
Author(s):  
Mitsuru Saito ◽  
Ryoko Sone ◽  
Masao Ikeda ◽  
Tadaaki Mano
Keyword(s):  
Skeletal Muscle ◽  
Heart Rate ◽  
Blood Lactate ◽  
Muscle Sympathetic Nerve Activity ◽  
Initial Period ◽  
Lactate Concentration ◽  
Blood Lactate Concentration ◽  
Tympanic Temperature ◽  
Exercise Heart Rate ◽  
Dependent Manner

Saito, Mitsuru, Ryoko Sone, Masao Ikeda, and Tadaaki Mano.Sympathetic outflow to the skeletal muscle in humans increases during prolonged light exercise. J. Appl. Physiol. 82(4): 1237 – 1243, 1997.—To investigate the effects of exercise duration on muscle sympathetic nerve activity (MSNA), heart rate, blood pressure (BP), tympanic temperature, blood lactate concentration, and thigh electromyogram were measured in eight volunteers during 30 min of cycling in the sitting position at an intensity of 40% of maximal oxygen uptake. MSNA burst frequency increased 18 min after exercise was begun (25 ± 4 bursts/min at baseline and 36 ± 5 bursts/min at 21 min of exercise), reaching 41 ± 5 bursts/min at the end of exercise. Heart rate and systolic BP increased during exercise. Twenty minutes after commencement of exercise, however, both systolic and diastolic BP values tended to drop compared with the initial period of exercise. Tympanic temperature increased in a time-dependent manner, and the increment was significant 12 min after exercise was begun. Blood lactate concentration and integrated electromyogram showed no significant changes during exercise. The increased MSNA during prolonged light-intensity exercise may be a secondary effect of the drop in BP as a result of blood redistribution caused by thermoregulation rather than by metaboreflex.

scholarly journals Análisis de la intensidad de juego durante los partidos de play-off en jugadores de baloncesto en silla de ruedas (Game intensity analysis of wheelchair basketball players during play-off matches)

Retos ◽  
2016 ◽  
pp. 54-58 ◽  
Author(s):  
Aitor Iturricastillo Urteaga ◽  
Javier Yanci Irigoyen ◽  
Itziar Barrenetxea Iriondo ◽  
Cristina Granados Dominguez
Keyword(s):  
Heart Rate ◽  
Body Temperature ◽  
Blood Lactate ◽  
Lactate Concentration ◽  
Blood Lactate Concentration ◽  
Tympanic Temperature ◽  
Intensity Analysis ◽  
Wheelchair Basketball ◽  
Basketball Players ◽  
Los Grupos

El principal objetivo del estudio fue analizar la intensidad de juego en jugadores de baloncesto en silla de ruedas (BSR) durante los partidos de play-off. En este estudio participaron nueve jugadores masculinos de BSR de primera división (34,8 ± 7,8 años). En total se analizaron seis partidos y los participantes fueron divididos en tres grupos según los minutos jugados: jugadores que jugaron 30-40 minutos (BSR30-40), jugadores que jugaron 20-29 minutos (BSR20-30) y los que jugaron entre 1 segundo y 19 minutos (BSR1-19). Durante todos los partidos se monitorizó la frecuencia cardíaca (FC), y además, se obtuvo la temperatura timpánica y la concentración de lactato sanguíneo antes e inmediatamente después de cada partido. Se encontraron diferencias significativas (P<0,05) en todas las zonas de intensidad entre el grupo BSR30-40 y BSR1-19. Los jugadores BSR30-40 pasaron un 36,4% del tiempo total por encima del 85% de la FCmáx, mientras que los jugadores BSR20-30 y BSR1-19 solo pasaron un 16,1 y un 9,2% del tiempo total. En todos los grupos tanto la temperatura timpánica (1,5-2,0%, P<0,05) como la concentración de lactato (81,1-125,0%, P<0,05) aumentó significativamente. Los resultados obtenidos en nuestro estudio exponen que los jugadores del grupo BSR30-40 pasaron mayor porcentaje de tiempo a alta intensidad (>85% de la FCmáx), con un aumento significativo de la temperatura y la concentración de lactato sanguíneo. Los entrenadores y preparadores físicos deberían tener en cuenta estas diferencias fisiológicas en función de los minutos jugados a la hora de planificar la temporada y los descansos post partido.Abstract. The main objective of the study was to analyze the game intensity in wheelchair basketball players (WB) during play-off matches. This study involved nine WB players of Spanish first division league (34.8 ± 7.8 years). Six play-off matches were analyzed and participants were divided into three groups according to the minutes they had played: players who had played between 30-40 minutes (WB30-40), players who had played between 20-30 minutes (WB20-30) and players who had played between 1 second and 20 minutes (WB1-19). For every game the heart rate (HR) was monitored by telemetry, and in addition, the tympanic temperature and blood lactate concentration samples were obtained before and immediately after each match. Significant differences (P<0.05) were observed in all intensity zones between WB30-40 and WB1-19 groups. The WB30-40 players spent 36.4% of the total time over 85% of maximum HR, while WB20-30 and WB1-19 players only spent 16.1 and 9.2% of the total time. Moreover, in all groups both tympanic temperature (from 1.5 to 2.0%, P<0.05) and lactate concentration (81.1 to 125.0%, P <0.05) increased significantly. The game intensity monitored by HR is different for WB players according to the minutes they had played (WB30-40, WB20-30 and WB1-19). The results of our study showed that the WB30-40 group obtained higher percentage of time spent at high intensity (> 85% of maximum HR) than other groups, with a significant increase in body temperature and blood lactate concentration. Coaches and physical trainers should be aware of these physiological differences when planning the season and post-match sessions.

scholarly journals Effects of a 2-km Swim on Markers of Cycling Performance in Elite Age-Group Triathletes

Sports ◽  
2019 ◽  
Vol 7 (4) ◽  
pp. 82
Author(s):  
Jeffrey Rothschild ◽  
George H. Crocker
Keyword(s):  
Heart Rate ◽  
Oxygen Consumption ◽  
Blood Lactate ◽  
Peak Power ◽  
Maximal Oxygen Consumption ◽  
Lactate Concentration ◽  
Blood Lactate Concentration ◽  
Cycling Performance ◽  
Age Group

The purpose of this study was to examine the effects of a 2-km swim on markers of subsequent cycling performance in well-trained, age-group triathletes. Fifteen participants (10 males, five females, 38.3 ± 8.4 years) performed two progressive cycling tests between two and ten days apart, one of which was immediately following a 2-km swim (33.7 ± 4.1 min). Cycling power at 4-mM blood lactate concentration decreased after swimming by an average of 3.8% (p = 0.03, 95% CI −7.7, 0.2%), while heart rate during submaximal cycling (220 W for males, 150 W for females) increased by an average of 4.0% (p = 0.02, 95% CI 1.7, 9.7%), compared to cycling without prior swimming. Maximal oxygen consumption decreased by an average of 4.0% (p = 0.01, 95% CI −6.5, −1.4%), and peak power decreased by an average of 4.5% (p < 0.01, 95% CI −7.3, −2.3%) after swimming, compared to cycling without prior swimming. Results from this study suggest that markers of submaximal and maximal cycling are impaired following a 2-km swim.

scholarly journals Fetal heart rate short term variation during labor in relation to scalp blood lactate concentration

2018 ◽  
Vol 97 (10) ◽  
pp. 1274-1280 ◽  
Author(s):  
Ke Lu ◽  
Malin Holzmann ◽  
Fahrad Abtahi ◽  
Kaj Lindecrantz ◽  
Pelle G Lindqvist ◽  
...  
Keyword(s):  
Heart Rate ◽  
Blood Lactate ◽  
Fetal Heart Rate ◽  
Fetal Heart ◽  
Lactate Concentration ◽  
Blood Lactate Concentration ◽  
Short Term ◽  
Term Variation

Temporal sequence of recovery-related events following maximal exercise assessed by heart rate variability and blood lactate concentration

2016 ◽  
Vol 37 (5) ◽  
pp. 536-543 ◽  
Author(s):  
Rosangela Akemi Hoshi ◽  
Luiz Carlos Marques Vanderlei ◽  
Moacir Fernandes de Godoy ◽  
Fábio do Nascimento Bastos ◽  
Jayme Netto ◽  
...  
Keyword(s):  
Heart Rate ◽  
Heart Rate Variability ◽  
Blood Lactate ◽  
Maximal Exercise ◽  
Lactate Concentration ◽  
Blood Lactate Concentration ◽  
Temporal Sequence

scholarly journals Influence of Intensity RAMP Incremental Test on Peak Power, Post-Exercise Blood Lactate, and Heart Rate Recovery in Males: Cross-Over Study

2019 ◽  
Vol 16 (20) ◽  
pp. 3934
Author(s):  
Kamil Michalik ◽  
Kuba Korta ◽  
Natalia Danek ◽  
Marcin Smolarek ◽  
Marek Zatoń
Keyword(s):  
Heart Rate ◽  
Blood Lactate ◽  
Peak Power ◽  
Design Method ◽  
Heart Rate Recovery ◽  
Lactate Concentration ◽  
Blood Lactate Concentration ◽  
Peak Power Output ◽  
Maximal Heart Rate ◽  
Incremental Test

Background: The linearly increased loading (RAMP) incremental test is a method commonly used to evaluate physical performance in a laboratory, but the best-designed protocol remains unknown. The aim of this study was to compare the selected variables used in training control resulting from the two different intensities of RAMP incremental tests. Methods: Twenty healthy and physically active men took part in this experiment. The tests included two visits to a laboratory, during which anthropometric measurements, incremental test on a cycle ergometer, and examinations of heart rate and blood lactate concentration were made. The cross-over study design method was used. The subjects underwent a randomly selected RAMP test with incremental load: 0.278 W·s−1 or 0.556 W·s−1. They performed the second test a week later. Results: Peak power output was significantly higher by 51.69 W (p < 0.001; t = 13.10; ES = 1.13) in the 0.556 W·s−1 group. Total work done was significantly higher in the 0.278 W·s−1 group by 71.93 kJ (p < 0.001; t = 12.55; ES = 1.57). Maximal heart rate was significantly higher in the 0.278 W·s−1 group by 3.30 bpm (p < 0.01; t = 3.72; ES = 0.48). There were no statistically significant differences in heart rate recovery and peak blood lactate. Conclusions: We recommend use of the 0.556 W·s−1 RAMP protocol because it is of shorter duration compared with 0.278 W·s−1 and as such practically easier and of less effort for subjects.

The diving physiology of bottlenose dolphins (Tursiops truncatus). I. Balancing the demands of exercise for energy conservation at depth

1999 ◽  
Vol 202 (20) ◽  
pp. 2739-2748 ◽  
Author(s):  
T.M. Williams ◽  
J.E. Haun ◽  
W.A. Friedl
Keyword(s):  
Heart Rate ◽  
Blood Lactate ◽  
Tursiops Truncatus ◽  
Marine Mammals ◽  
Bottlenose Dolphins ◽  
Lactate Concentration ◽  
Blood Lactate Concentration ◽  
Energetic Cost ◽  
Breath Holding ◽  
Breath Hold

During diving, marine mammals must rely on the efficient utilization of a limited oxygen reserve sequestered in the lungs, blood and muscles. To determine the effects of exercise and apnea on the use of these reserves, we examined the physiological responses of adult bottlenose dolphins (Tursiops truncatus) trained to breath-hold on the water surface or to dive to submerged targets at depths between 60 and 210 m. Changes in blood lactate levels, in partial pressures of oxygen and carbon dioxide and in heart rate were assessed while the dolphins performed sedentary breath-holds. The effects of exercise on breath-hold capacity were examined by measuring heart rate and post-dive respiration rate and blood lactate concentration for dolphins diving in Kaneohe Bay, Oahu, Hawaii. Ascent and descent rates, stroke frequency and swimming patterns were monitored during the dives. The results showed that lactate concentration was 1.1+/−0.1 mmol l(−1) at rest and increased non-linearly with the duration of the sedentary breath-hold or dive. Lactate concentration was consistently higher for the diving animals at all comparable periods of apnea. Breakpoints in plots of lactate concentration and blood gas levels against breath-hold duration (P(O2), P(CO2)) for sedentary breath-holding dolphins occurred between 200 and 240 s. In comparison, the calculated aerobic dive limit for adult dolphins was 268 s. Descent and ascent rates ranged from 1.5 to 2.5 m s(−1) during 210 m dives and were often outside the predicted range for swimming at low energetic cost. Rather than constant propulsion, diving dolphins used interrupted modes of swimming, with more than 75 % of the final ascent spent gliding. Physiological and behavioral measurements from this study indicate that superimposing swimming exercise on apnea was energetically costly for the diving dolphin but was circumvented in part by modifying the mode of swimming.

Mechanisms of Performance Improvements Due to a Leading Teammate During Uphill Cycling

2018 ◽  
Vol 13 (9) ◽  
pp. 1215-1222 ◽  
Author(s):  
Theo Ouvrard ◽  
Alain Groslambert ◽  
Gilles Ravier ◽  
Sidney Grosprêtre ◽  
Philippe Gimenez ◽  
...  
Keyword(s):  
Heart Rate ◽  
Blood Lactate ◽  
Perceived Exertion ◽  
Lactate Concentration ◽  
Blood Lactate Concentration ◽  
Attentional Focus ◽  
Rating Of Perceived Exertion ◽  
Strong Impact ◽  
Competitive Cyclists ◽  
The Impact

Purpose: To identify the impact of a leading teammate in front of a cyclist on psychological, physiological, biomechanical, and performance parameters during an uphill maximal effort. Methods: After familiarization, 12 well-trained competitive cyclists completed 2 uphill time trials (UTTs, 2.7 km at 7.4%) in randomized order; that is, 1 performed alone (control condition) and 1 followed a simulated teammate during the entire UTT (leader condition). Performance (UTT time) and mean power output (PO) were recorded for each UTT. For physiological parameters, mean heart rate and postexercise blood lactate concentration were recorded. Psychological parameters (rating of perceived exertion, pleasure, and attentional focus) were collected at the end of each trial. Results: Performance (UTT time) significantly improved by 4.2% (3.1%) in the leader condition, mainly due to drafting decrease of the aerodynamic drag (58% of total performance gains) and higher end spurt (+9.1% [9.1%] of mean PO in the last 10% of the UTT). However, heart rate and postexercise blood lactate concentration were not significantly different between conditions. From a psychological aspect, higher pleasure was observed in the leader condition (+41.1% [51.7%]), but attentional focus was not significantly different. Conclusions: The presence of a leading teammate during uphill cycling had a strong impact on performance, enabling higher speed for the same mean PO and greater end spurt. These results explain why the best teams competing for the general classification of the most prestigious and contested races like the Grand Tours tend to always protect their leader with teammates during decisive ascents.

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