Reliability of peak-lactate, heart rate, and plasma volume following the Wingate test

Mean control data on a series of 100 dogs are presented. Cell volume, measured with Cr51-tagged red cells and plasma volume determined simultaneously by T-1824 dye was 33.5 ± 0.74 cc/kg and 50.2 ± 1.11 cc/kg, respectively. The venous hematocrit was 45.2% and the circulatory/venous hematocrit ratio was 0.89 ± 0.01 for the group. The plasma protein concentration of these animals was 6.25 ± 0.07 gm/100 cc. No difference in blood volume per unit of body weight was found between large (12.6 kg) and small (5.8 kg) dogs. The femoral mean systolic pressure was 139.0 ± 2.53 mm Hg, the diastolic pressure 65.6 ± 1.46 mm Hg and the heart rate 85.9 ± 2.86/min.

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Effect of head-down-tilt bed rest and hypovolemia on dynamic regulation of heart rate and blood pressure

AJP Regulatory Integrative and Comparative Physiology ◽

10.1152/ajpregu.2000.279.6.r2189 ◽

2000 ◽

Vol 279 (6) ◽

pp. R2189-R2199 ◽

Cited By ~ 86

Author(s):

Ken-Ichi Iwasaki ◽

Rong Zhang ◽

Julie H. Zuckerman ◽

James A. Pawelczyk ◽

Benjamin D. Levine

Keyword(s):

Blood Pressure ◽

Heart Rate ◽

Transfer Function ◽

Stroke Volume ◽

Plasma Volume ◽

High Frequency ◽

Function Analysis ◽

Bed Rest ◽

Baroreflex Control ◽

Transfer Function Analysis

Adaptation to head-down-tilt bed rest leads to an apparent abnormality of baroreflex regulation of cardiac period. We hypothesized that this “deconditioning response” could primarily be a result of hypovolemia, rather than a unique adaptation of the autonomic nervous system to bed rest. To test this hypothesis, nine healthy subjects underwent 2 wk of −6° head-down bed rest. One year later, five of these same subjects underwent acute hypovolemia with furosemide to produce the same reductions in plasma volume observed after bed rest. We took advantage of power spectral and transfer function analysis to examine the dynamic relationship between blood pressure (BP) and R-R interval. We found that 1) there were no significant differences between these two interventions with respect to changes in numerous cardiovascular indices, including cardiac filling pressures, arterial pressure, cardiac output, or stroke volume; 2) normalized high-frequency (0.15–0.25 Hz) power of R-R interval variability decreased significantly after both conditions, consistent with similar degrees of vagal withdrawal; 3) transfer function gain (BP to R-R interval), used as an index of arterial-cardiac baroreflex sensitivity, decreased significantly to a similar extent after both conditions in the high-frequency range; the gain also decreased similarly when expressed as BP to heart rate × stroke volume, which provides an index of the ability of the baroreflex to alter BP by modifying systemic flow; and 4) however, the low-frequency (0.05–0.15 Hz) power of systolic BP variability decreased after bed rest (−22%) compared with an increase (+155%) after acute hypovolemia, suggesting a differential response for the regulation of vascular resistance (interaction, P < 0.05). The similarity of changes in the reflex control of the circulation under both conditions is consistent with the hypothesis that reductions in plasma volume may be largely responsible for the observed changes in cardiac baroreflex control after bed rest. However, changes in vasomotor function associated with these two conditions may be different and may suggest a cardiovascular remodeling after bed rest.

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Effect of sauna-based heat acclimation on plasma volume and heart rate variability

European Journal of Applied Physiology ◽

10.1007/s00421-014-3060-1 ◽

2014 ◽

Vol 115 (4) ◽

pp. 785-794 ◽

Cited By ~ 46

Author(s):

Jamie Stanley ◽

Aaron Halliday ◽

Shaun D’Auria ◽

Martin Buchheit ◽

Anthony S. Leicht

Keyword(s):

Heart Rate ◽

Heart Rate Variability ◽

Plasma Volume ◽

Heat Acclimation

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Effects of Prizidilol (SKF 92657) on Blood Pressure, Haemodynamics, Sympathetic Nervous System Activity and Plasma Volume in Essential Hypertension

Clinical Science ◽

10.1042/cs061465s ◽

1981 ◽

Vol 61 (s7) ◽

pp. 465s-468s ◽

Cited By ~ 9

Author(s):

R. Fariello ◽

C. L. Alicandri ◽

E. Agabiti-Rosei ◽

G. Romanelli ◽

M. Castellano ◽

...

Keyword(s):

Blood Pressure ◽

Heart Rate ◽

Plasma Volume ◽

Antihypertensive Effect ◽

Blood Pressure Reduction ◽

Cardiac Performance ◽

Plasma Aldosterone ◽

Nervous System Activity ◽

Peripheral Vasodilatation ◽

Noradrenaline And Adrenaline

1. The antihypertensive effect of 4 weeks' treatment with prizidilol (SKF 92657) (mean dosage 520 mg once or twice daily) was studied in ten essential hypertensive patients. 2. Both systolic and diastolic blood pressure were significantly reduced in all cases. Supine heart rate did not change, and in the erect position heart rate was significantly lowered. 3. Blood pressure reduction was due to peripheral vasodilatation, as the cardiac index increased after 4 weeks of prizidilol treatment. 4. After prizidilol plasma noradrenaline and adrenaline increased significantly, and PRA and plasma aldosterone were reduced. Although plasma volume increased, body weight did not change. 5. Cardiac performance, as evaluated by the PEP/LVET ratio, improved after treatment with prizidilol.

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Effects of V1- and V2-vasopressin (AVP) antagonists on the pressor, AVP and atrial natriuretic peptide responses to a hypertonic saline infusion in conscious anephric rats

Acta Endocrinologica ◽

10.1530/eje.0.1330127 ◽

1995 ◽

Vol 133 (1) ◽

pp. 127-132 ◽

Cited By ~ 4

Author(s):

Kozo Ota ◽

Tokihisa Kimura ◽

Minoru Inoue ◽

Takeharu Funyu ◽

Masaru Shoji ◽

...

Keyword(s):

Heart Rate ◽

Mean Arterial Pressure ◽

Arterial Pressure ◽

Atrial Natriuretic Peptide ◽

Receptor Antagonist ◽

Hypertonic Saline ◽

Natriuretic Peptide ◽

Plasma Volume ◽

Control Group ◽

Antagonist Group

Ota K, Kimura T, Inoue M, Funyu T, Shoji M, Sato K, Ohta M, Yamamoto T, Abe K, Effects of V1- and V2-vasopressin (AVP) antagonists on the pressor, AVP and atrial natriuretic peptide responses to a hypertonic saline infusion in conscious anephric rats. Eur J Endocrinol 1995;133:127–32. ISSN 0804–4643 To examine the role of vasopressin (AVP) receptors in the regulation of the hemodynamics and release of atrial natriuretic peptide (ANP), and the participation of renal nerve inputs in the osmotic AVP release, hypertonic saline (HS) was infused into conscious, bilaterally nephrectomized rats with nonpeptide, selective antagonists for the V1-receptor or V2-receptor of AVP. In the control group, HS alone increased mean arterial pressure, plasma ANP and AVP, plasma volume and plasma osmolality, and decreased the heart rate. In the V1-receptor antagonist group, an increase in the mean arterial pressure and a decrease in heart rate were completely abolished and an increase in plasma ANP was attenuated. In the V2-receptor antagonist group, increases in mean arterial pressure and plasma ANP and a decrease in heart rate were attenuated. However, the ratio of the changes in heart rate to the changes in mean arterial pressure in the V2-receptor antagonist group is significantly higher than that in the control group. In both experimental groups, increases in plasma AVP, plasma volume and plasma osmolality were not different from those in the control group. These results suggest that a HS-induced increase in mean arterial pressure is mediated by the pressor effect of AVP, mainly through V1-receptors, and that the depressor effect of AVP through V2-receptors may not influence tonically HS-induced hypertension. Moreover, HS-induced increase in plasma ANP is mediated mainly by increases in plasma volume and blood pressure, but may not be affected by a direct action of AVP to the heart. Renal afferent nerve inputs may not have effects on the regulation of osmotic AVP release. Kozo Ota, Second Department of Internal Medicine, Tohoku University School of Medicine, 1-1 Seiryo-cho, Aoba-ku, Sendai 980-77, Japan

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Heart rate dynamics and lactate following high-intensity race-pace continuous vs interval workouts in highly trained athletes

Physiology International ◽

10.1556/2060.2021.00153 ◽

2021 ◽

Author(s):

I. Martinez-Navarro ◽

A. Montoya ◽

M. Mateo-March ◽

C. Blasco-Lafarga

Keyword(s):

Heart Rate ◽

High Intensity ◽

Interval Training ◽

Fluctuation Analysis ◽

Post Exercise ◽

Vagal Modulation ◽

Heart Rate Dynamics ◽

Peak Lactate ◽

Linear And Nonlinear ◽

Age Category

AbstractPurposeThe present study aimed to compare the physiological responses of high-intensity race-pace continuous vs. interval workouts commonly used in middle-distance athletics, by means of analyzing post-exercise cardiac autonomic regulation and lactate.MethodsNineteen highly-trained 800-m male runners were asked to run a 600-m race-pace continuous workout and a 2 × 4 × 200-m interval training, counterbalanced and randomized within one week of difference. Blood lactate jointly with linear and nonlinear heart rate dynamics were assessed during the immediate 15-min recovery. Age-category (Under23-Senior vs. Juvenile-Junior) was considered as an inter-subject factor.ResultsPeak lactate was higher following the interval training (15.51 ± 0.99 vs 13.83 ± 1.77 mmol L−1; P < 0.05) whereas lactate removal was almost nonexistent 15 min after both workouts (between 0 and 16%). Vagal modulation (ln RMSSD and lnRMSSD to RR ratio) remained significantly depressed at the end of recovery following both workouts, although the alteration was larger following the interval training. Detrended Fluctuation Analysis evidenced a more random HR behavior (DFA1 closer to 0.5) during the first 9 min of recovery after the interval training, whereas no significant change was observed in heart rate complexity (SampEn). Neither were differences found in post-exercise lactate and HR dynamics as a function of age-category.ConclusionsHigh-intensity workouts commonly used in middle-distance athletics, both race-pace continuous and intervallic approaches, induce a large depression of vagal modulation in highly trained runners, although interval trainings appear to induce even a greater alteration of both linear and nonlinear HR dynamics and a higher post-exercise peak lactate.

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Acute plasma volume expansion: effect on metabolism during submaximal exercise

Journal of Applied Physiology ◽

10.1152/jappl.1999.87.3.1202 ◽

1999 ◽

Vol 87 (3) ◽

pp. 1202-1206 ◽

Cited By ~ 4

Author(s):

Matthew J. Watt ◽

Mark A. Febbraio ◽

Andrew P. Garnham ◽

Mark Hargreaves

Keyword(s):

Heart Rate ◽

Oxygen Uptake ◽

Plasma Volume ◽

Volume Expansion ◽

Venous Blood ◽

Submaximal Exercise ◽

Plasma Catecholamine ◽

Substrate Selection ◽

Plasma Volume Expansion ◽

Total Carbohydrate

To examine the effect of acute plasma volume expansion (PVE) on substrate selection during exercise, seven untrained men cycled for 40 min at 72 ± 2% peak oxygen uptake (V˙o 2 peak) on two occasions. On one occasion, subjects had their plasma volume expanded by 12 ± 2% via an intravenous infusion of the plasma substitute Haemaccel, whereas on the other occasion no such infusion took place. Muscle samples were obtained before and immediately after exercise. In addition, heart rate and pulmonary gas and venous blood samples were obtained throughout exercise. No differences in oxygen uptake or heart rate during exercise were observed between trials, whereas respiratory exchange ratio, blood glucose, and lactate were unaffected by PVE. Muscle glycogen and lactate concentrations were not different either before or after exercise. In addition, there was no difference in total carbohydrate oxidation between trials (control: 108 ± 2 g; PVE group: 105 ± 2 g). Plasma catecholamine levels were not affected by PVE. These data indicate that substrate metabolism during submaximal exercise in untrained men is unaltered by acute hypervolemia.

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Responses to Moderate and Low Sodium Diets during Exercise-Heat Acclimation

International Journal of Sport Nutrition ◽

10.1123/ijsn.3.2.207 ◽

1993 ◽

Vol 3 (2) ◽

pp. 207-221 ◽

Cited By ~ 14

Author(s):

Lawrence E. Armstrong ◽

Roger W. Hubbard ◽

E. Wayne Askew ◽

Jane P. De Luca ◽

Catherine O'Brien ◽

...

Keyword(s):

Heart Rate ◽

Plasma Volume ◽

Rectal Temperature ◽

Prolonged Exercise ◽

Heat Acclimation ◽

Treadmill Walking ◽

Heat Illness ◽

Low Sodium ◽

Physiologic Function ◽

Physiologic Responses

This investigation examined whether low sodium (Na+) (LNA; 68 mEq Na+·d-1) or moderate Na+(MNA; 137 mEq Na+.d-1) intake allowed humans to maintain health, exercise, and physiologic function during 10 days of prolonged exercise-heat acclimation (HA). Seventeen volunteers, ages 19 to 21, consumed either LNA (n=8) or MNA (n=9) during HA (41°C, 21% RH; treadmill walking for 30 min.h-1, 8 h·d-1at 5.6 kmh-l, 5% grade), which resulted in significantly reduced heart rate, rectal temperature, and urine Na+for both groups. There were few between-diet differences in any variables measured. Mean plasma volume in LNA expanded significantly less than in MNA by Days 11 and 15, but reached the MNA level on Day 17 (+12.3 vs. +12.4%). The absence of heat illness, the presence of normal physiologic responses, and the total distance walked indicated successful and similar HA with both levels of dietary Na+.

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Cardiorespiratory deconditioning with static and dynamic leg exercise during bed rest

Journal of Applied Physiology ◽

10.1152/jappl.1976.41.6.905 ◽

1976 ◽

Vol 41 (6) ◽

pp. 905-909 ◽

Cited By ~ 52

Author(s):

R. W. Stremel ◽

V. A. Convertino ◽

E. M. Bernauer ◽

J. E. Greenleaf

Keyword(s):

Heart Rate ◽

Plasma Volume ◽

Rest Period ◽

Bed Rest ◽

Bicycle Ergometer ◽

Dynamic Exercise ◽

Maximal Heart Rate ◽

Leg Extension ◽

Ergometer Exercise ◽

Extension Force

Bed rest deconditioning was assessed in seven healthy men (19–22 yr) following three 14-day periods of controlled activity during recumbencyby measuring submaximal and maximal oxygen uptake (VO2), ventilation (VE), heart rate, and plasma volume. Exercise regimens were performed in the supine position and included a) two 30-min periods daily of intermittent staticexercise at 21% of maximal leg extension force, and b) two 30-min periods of dynamic bicycle ergometer exercise daily at 68% of VO2max. No prescribed exercise was performed during the third bed rest period. Compared with their respective pre-bed rest control values, VO2max decreased (P less than 0.05) under all exercise conditions; -12.3% with no exercise, -9.2% with dynamic exercise, but only -4.8% with static exercise. Maximal heart rate was increased by 3.3% to 4.9% (P less than 0.05) under the three exercise conditions, while plasma volume decreased (P less than 0.05) -15.1% with no exercise and -10.1% with static, but only -7.8% (NS) with dynamic exercise. Sinceneither the static nor dynamic exercise training regimes minimized the changes in all the variables studied, some combination of these two types of exercise may be necessary for maximum protection from the effects of the bed deconditioning.

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