Comparison of Sweat Rate Measured by a Pouch Collector and a Hygrometric Technique During Exercise

1997 ◽  
Vol 22 (2) ◽  
pp. 161-170 ◽  
Author(s):  
Paul Boisvert ◽  
Anne-Virginie Desruelle ◽  
Victor Candas
Keyword(s):  
Sweat Rate ◽  
Young Male ◽  
Field Method ◽  
Cycle Ergometer ◽  
Mean Values ◽  
Hot Environment ◽  
Time Period ◽  
Local Sweat Rate ◽  
The Difference ◽  
Male Subjects

Measurements of local sweat rate (back) determined with a closed-pouch collector made of polyethylene (110 cm2) were compared with those obtained from a ventilated capsule using an infrared photometric hygrometer technique. Eight young male subjects underwent three exercise sessions each for 60 min at 45% [Formula: see text] on a cycle ergometer at an ambient temperature of 35 °C and 35% relative humidity. When the onset and transient sweating periods (0-20 min) are excluded from calculations, the difference between the mean values obtained by the collector and the sweat capsule during the 20-60 time period is only 0.06 ± 0.04 mg • cm−2 • min−1 (5%). Although a significant correlation (r = .74, p < .05) was obtained between methods, individual differences in sweat-rate measurements varied on average ±0.22 mg • cm−2 • min−1 (±19%). Designed more specifically for sweat-content analysis, the pouch collector may serve as a satisfactory field method to approximate the local sweat rate and excretion induced by prolonged exercise in a hot environment. Key words: sweating assessment, methodology, thermoregulation, skin temperature

scholarly journals Analysis of Individual Variations in Autonomic Responses to Urban and Forest Environments

2015 ◽  
Vol 2015 ◽  
pp. 1-7 ◽  
Author(s):  
Hiromitsu Kobayashi ◽  
Chorong Song ◽  
Harumi Ikei ◽  
Takahide Kagawa ◽  
Yoshifumi Miyazaki
Keyword(s):  
Heart Rate ◽  
Urban Areas ◽  
Young Male ◽  
Autonomic Activity ◽  
Mean Values ◽  
Autonomic Responses ◽  
Conventional Analysis ◽  
Individual Variations ◽  
The Difference ◽  
Male Subjects

Autonomic responses to urban and forest environments were studied in 625 young male subjects. The experimental sites were 57 forests and 57 urban areas across Japan. The subjects viewed the landscape (forest or urban environment) for a period of 15 min while sitting on a chair. During this period, heart rate variability (HRV) was monitored continuously. The results were presented as histograms and analyzed with special reference to individual variations. Approximately 80% of the subjects showed an increase in the parasympathetic indicator of HRV (lnHF), whereas the remaining subjects showed a decrease in the parasympathetic activity. Similarly, 64.0% of the subjects exhibited decreases in the sympathetic indicator of HRV (ln[LF/HF]), whereas the remaining subjects showed opposite responses. Analysis of the distribution of HRV indices (lnHF and ln[LF/HF]) demonstrated the effect of forest environments on autonomic activity more specifically than the conventional analysis based on the difference in mean values.

Comparison of two noninvasive techniques for estimating cardiac output during exercise

1986 ◽  
Vol 61 (1) ◽  
pp. 155-159 ◽  
Author(s):  
D. D. Hatcher ◽  
O. D. Srb
Keyword(s):  
Cardiac Output ◽  
Large Range ◽  
Impedance Plethysmography ◽  
Cycle Ergometer ◽  
O2 Consumption ◽  
Noninvasive Techniques ◽  
Transthoracic Impedance ◽  
The Mean ◽  
The Difference ◽  
Male Subjects

This study presents the comparison of two different noninvasive techniques for the estimation of cardiac output (Q). The two techniques used were transthoracic impedance plethysmography (Z) and the indirect Fick CO2 rebreathing (RB) method. Paired estimates of Q were made on 60 different male subjects at rest and during graded increments of work on a cycle ergometer. The mean resting Q as measured by the Z technique (COZ) was 7.46 +/- 0.35 and 5.96 +/- 0.43 l/min using the RB (CORB) technique. At 200 W the mean COZ was 18.67 +/- 0.72 l/min and the CORB was 23.73 +/- 0.84 l/min. Both the techniques were linearly correlated (R) with O2 consumption; i.e., RZ = 0.752, RRB = 0.855. The difference between these two R values is statistically significant (P less than 0.001). A linear relationship was found between the Z and RB techniques at all work loads (R = 0.75). This study suggests that both techniques are equally as reliable over a large range of work loads, with the Z technique being the simplest and most efficient to implement. It was also found that lung volume had no effect on the calculated COZ.

Heart rate performance curve during incremental cycle ergometer exercise in healthy young male subjects

1997 ◽  
Vol 29 (6) ◽  
pp. 762-768 ◽  
Author(s):  
PETER HOFMANN ◽  
ROCHUS POKAN ◽  
SERGE P. VON DUVILLARD ◽  
&NA; J. SEIBERT ◽  
ROBERT ZWEIKER ◽  
...  
Keyword(s):  
Heart Rate ◽  
Young Male ◽  
Cycle Ergometer ◽  
Performance Curve ◽  
Rate Performance ◽  
Cycle Ergometer Exercise ◽  
Ergometer Exercise ◽  
Male Subjects

scholarly journals Determining Bounds on Assumption Errors in Operational Analysis

2014 ◽  
Vol 2014 ◽  
pp. 1-10
Author(s):  
Neal M. Bengtson
Keyword(s):  
Performance Measures ◽  
Response Times ◽  
Kkt Conditions ◽  
Tolerance Limits ◽  
Basic Principles ◽  
Mean Values ◽  
Operational Analysis ◽  
Error Measures ◽  
Time Period ◽  
The Difference

The technique of operational analysis (OA) is used in the study of systems performance, mainly for estimating mean values of various measures of interest, such as, number of jobs at a device and response times. The basic principles of operational analysis allow errors in assumptions to be quantified over a time period. The assumptions which are used to derive the operational analysis relationships are studied. Using Karush-Kuhn-Tucker (KKT) conditions bounds on error measures of these OA relationships are found. Examples of these bounds are used for representative performance measures to show limits on the difference between true performance values and those estimated by operational analysis relationships. A technique for finding tolerance limits on the bounds is demonstrated with a simulation example.

Exercise-Induced Trace Mineral Element Concentration in Regional Versus Whole-Body Wash-Down Sweat

2011 ◽  
Vol 21 (3) ◽  
pp. 233-239 ◽  
Author(s):  
Lindsay B. Baker ◽  
John R. Stofan ◽  
Henry C. Lukaski ◽  
Craig A. Horswill
Keyword(s):  
Element Concentration ◽  
Sweat Rate ◽  
Sulfate Solution ◽  
Skin Surface ◽  
Cycle Ergometer ◽  
Whole Body ◽  
Air Chamber ◽  
Local Sweat Rate ◽  
Exercise Induced ◽  
Sweat Composition

Simultaneous whole-body wash-down (WBW) and regional skin surface sweat collections were completed to compare regional patch and WBW sweat calcium (Ca), magnesium (Mg), copper (Cu), manganese (Mn), iron (Fe), and zinc (Zn) concentrations. Athletes (4 men, 4 women) cycled in a plastic open-air chamber for 90 min in the heat. Before exercise, the subjects and cycle ergometer (covered in plastic) were washed with deionized water. After the onset of sweating, sterile patches were attached to the forearm, back, chest, forehead, and thigh and removed on saturation. After exercise, the subjects and cycle ergometer were washed with 5 L of 15-mM ammonium sulfate solution to collect all sweat minerals and determine the volume of unevaporated sweat. Control trials were performed to measure mineral contamination in regional and WBW methods. Because background contamination in the collection system was high for WBW Mn, Fe, and Zn, method comparisons were not made for these minerals. After correction for minimal background contamination, WBW sweat [Ca], [Mg], and [Cu] were 44.6 ± 20.0, 9.8 ± 4.8, and 0.125 ± 0.069 mg/L, respectively, and 5-site regional (weighted for local sweat rate and body surface area) sweat [Ca], [Mg], and [Cu] were 59.0 ± 15.9, 14.5 ± 4.8, and 0.166 ± 0.031 mg/L, respectively. Five-site regional [Ca], [Mg], and [Cu] overestimated WBW by 32%, 48%, and 33%, respectively. No individual regional patch site or 5-site regional was significantly correlated with WBW sweat [Ca] (r = –.21, p = .65), [Mg] (r = .49, p = .33), or [Cu] (r = .17, p = .74). In conclusion, regional sweat [Ca], [Mg], and [Cu] are not accurate surrogates for or significantly correlated with WBW sweat composition.

scholarly journals Energy compensation after an aerobic exercise session in high-fat/low-fit and low-fat/high-fit young male subjects

2013 ◽  
Vol 110 (6) ◽  
pp. 1133-1142 ◽  
Author(s):  
Keyne Charlot ◽  
Didier Chapelot
Keyword(s):  
Aerobic Exercise ◽  
Young Male ◽  
Cycle Ergometer ◽  
Individual Variability ◽  
Exercise Session ◽  
High Fat ◽  
Energy Compensation ◽  
Group 2 ◽  
Exercise Induced ◽  
Male Subjects

There is general agreement that exercise-induced energy expenditure is not entirely compensated for at the next meal or over the following 24 h, but inter-individual variability is high. The role of ‘fatness and fitness’ in this variability has never been assessed. Therefore, eighteen non-obese male subjects aged 22·2 (sd2·0) years were selected and separated into a ‘high-fatness and low-fitness’ (Hfat/Lfit,n9) and a ‘low-fatness and high-fitness’ (Lfat/Hfit,n9) group, according to three criteria: maximal oxygen uptake; weekly hours of physical activity; fat mass index. At 1 h before lunch, they were subjected to 60 min of exercise on a cycle ergometer (70 % VO2max), or stayed at rest. Then, they self-reported food intake in diaries until the next breakfast. Intake at lunch was not different between conditions, but was higher after exercise than after rest over the 24 h, leading to a significant but partial mean level of compensation of 49·8 (sem16·5) and 37·8 (sem24·6) % for the Hfat/Lfit and Lfat/Hfit groups, respectively. Energy compensation at lunch and over the 24 h were strongly correlated (r0·76,P< 0·001). Both groups consumed more fat and protein after exercise than after rest over the 24 h, but the percentage of energy derived from fat increased only in the Hfat/Lfit group (2·1 (sem0·6) %,P= 0·026). Thus, the energy cost of an aerobic exercise session was partially compensated over the next 24 h independently of the ‘fatness and fitness’ status, but ‘high-fat and low-fit’ individuals compensated more specifically on fats.

Influence of the timing of fluid ingestion on temperature regulation during exercise

1993 ◽  
Vol 75 (2) ◽  
pp. 688-695 ◽  
Author(s):  
S. J. Montain ◽  
E. F. Coyle
Keyword(s):  
Body Weight ◽  
Heat Stress ◽  
Fluid Intake ◽  
Body Weight Loss ◽  
Sodium Concentration ◽  
Cycle Ergometer ◽  
Fluid Ingestion ◽  
Hot Environment ◽  
Time Period ◽  
Ergometer Exercise

The purpose of this investigation was to determine whether the timing of fluid ingestion affects thermoregulation during exercise-heat stress. On four occasions, seven endurance-trained cyclists [age 25 +/- 2 (SE) yr, body weight 70.5 +/- 3.3 kg, maximal O2 uptake (VO2max) 4.69 +/- 0.11 l/min] performed 140 min of cycle ergometer exercise at 62–66% of VO2max in a hot environment (33 degrees C dry bulb, 51% relative humidity, wind speed 2.5 m/s). The subjects drank 1,173 +/- 44 ml of a carbohydrate-electrolyte beverage after 0 min (D0), 40 min (D40), or 80 min (D80) of exercise or consumed the same total volume in small aliquots throughout exercise (DT). The exercise-heat stress resulted in calculated sweating rates of approximately 1,200 ml/h and a body weight loss of 2.9 +/- 0.1% after 140 min of exercise. After fluid intake in the D0, D40, and D80 trials, there was a time period (approximately 40 min) in which the increases in serum osmolality and sodium concentration and the reduction in blood volume were attenuated. During that same time period, there was an attenuated rise in esophageal temperature (Tes; P < 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Method for computing the oxidation of two 13C-substrates ingested simultaneously during exercise

1993 ◽  
Vol 75 (3) ◽  
pp. 1419-1422 ◽  
Author(s):  
F. Peronnet ◽  
E. Adopo ◽  
D. Massicotte ◽  
G. R. Brisson ◽  
C. Hillaire-Marcel
Keyword(s):  
Prolonged Exercise ◽  
Cycle Ergometer ◽  
Healthy Male ◽  
O2 Uptake ◽  
Oxidation Rates ◽  
Exogenous Glucose ◽  
Ergometer Exercise ◽  
The Difference ◽  
Endogenous Substrates ◽  
Male Subjects

This study presents a method for computing the respective amounts of two simultaneously ingested exogenous substrates (A and B) that are oxidized during a period of prolonged exercise by use of 13C labeling. This method is based on the observation that the total volume of 13CO2 produced (V13CO2tot) is the sum of 1) V13CO2 arising from the oxidation of endogenous substrates (V13CO2endo), 2) V13CO2 arising from the oxidation of substrate A (V13CO2A), and 3) V13CO2 arising from the oxidation of substrate B (V13CO2B). The equation, V13CO2tot = V13CO2endo+V13CO2A+V13CO2B, with three unknowns, can be solved from the results of three experiments conducted under the same conditions but with at least two values for the isotopic composition of A and B. This method has been used on five healthy male subjects to compute the amounts of glucose and fructose oxidized when a mixture of 15 g of glucose and 15 g of fructose is ingested (in 300 ml of water) over 60 min of cycle ergometer exercise at 65% of maximal O2 uptake. Results from three experiments indicated that 9.8 +/- 3.1 and 5.7 +/- 2.1 g of glucose and fructose, respectively, were oxidized. The total amount of exogenous carbohydrates oxidized (15.5 +/- 4.3 g) is in agreement with the oxidation rates of exogenous glucose computed in similar conditions when 30 g of glucose were ingested (13 g; Peronnet et al. Med. Sci. Sports Exercise 25: 297–302, 1993). The difference between the oxidation rates of exogenous glucose and fructose is also in line with data from the literature.

Ultrastructural Study of Human Testicular Biopsies in Infertility

1976 ◽  
Vol 34 ◽  
pp. 156-157
Author(s):  
Shirley Siew ◽  
Philip Troen ◽  
Howard R. Nankin
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Basement Membrane ◽  
Leydig Cells ◽  
Clinical Evidence ◽  
Young Male ◽  
Germinal Epithelium ◽  
Transmission Electron ◽  
Age Range ◽  
Male Subjects

Testicular biopsies were obtained from six young male subjects (age range 24-33) who complained of infertility and who had clinical evidence of oligospermia. This was confirmed on histological examination which showed a broad spectrum from profound hypospermatogenesis to relatively normal appearing germinal epithelium. Thickening of the tubular walls was noted in half of the cases and slight peritubular fibrosis in one. The Leydig cells were reported as normal or unremarkable.Transmission electron microscopy showed that the thickening of the supporting tissue of the germinal epithelium was caused more by an increase in the thickness of the layers of the lamina propria than of the tubular wall itself. The changes in the basement membrane of the tubular wall consisted mostly of a greater degree of infolding into the tubule and some reduplication which gave rise to a multilayered appearance.

Seasonal trends in the stable isotopic composition of snow and meltwater runoff in a subarctic catchment at Okstindan, Norway

2004 ◽  
Vol 35 (2) ◽  
pp. 119-137 ◽  
Author(s):  
S.D. Gurney ◽  
D.S.L. Lawrence
Keyword(s):  
Isotopic Composition ◽  
Mean Value ◽  
Mean Values ◽  
Stable Isotopic Composition ◽  
Meltwater Runoff ◽  
Stable Isotopic ◽  
The Mean ◽  
The Difference ◽  
Δ18o And Δd

Seasonal variations in the stable isotopic composition of snow and meltwater were investigated in a sub-arctic, mountainous, but non-glacial, catchment at Okstindan in northern Norway based on analyses of δ18O and δD. Samples were collected during four field periods (August 1998; April 1999; June 1999 and August 1999) at three sites lying on an altitudinal transect (740–970 m a.s.l.). Snowpack data display an increase in the mean values of δ18O (increasing from a mean value of −13.51 to −11.49‰ between April and August), as well as a decrease in variability through the melt period. Comparison with a regional meteoric water line indicates that the slope of the δ18O–δD line for the snowpacks decreases over the same period, dropping from 7.49 to approximately 6.2.This change points to the role of evaporation in snowpack ablation and is confirmed by the vertical profile of deuterium excess. Snowpack seepage data, although limited, also suggest reduced values of δD, as might be associated with local evaporation during meltwater generation. In general, meltwaters were depleted in δ18O relative to the source snowpack at the peak of the melt (June), but later in the year (August) the difference between the two was not statistically significant. The diurnal pattern of isotopic composition indicates that the most depleted meltwaters coincide with the peak in temperature and, hence, meltwater production.

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