Effect of age on heat-activated sweat gland density and flow during exercise in dry heat

1987 ◽  
Vol 63 (3) ◽  
pp. 1089-1094 ◽  
Author(s):  
R. K. Anderson ◽  
W. L. Kenney
Keyword(s):  
Older Women ◽  
Sweat Gland ◽  
Age Groups ◽  
Whole Body ◽  
Moderate Intensity ◽  
Exercise Session ◽  
Sweat Glands ◽  
Moderate Intensity Exercise ◽  
Age Related ◽  
Eccrine Glands

Physiological responses of eight postmenopausal older women (age 52–62 yr) and eight younger women (age 20–30 yr) were compared during moderate intensity exercise in a hot dry environment (48 degrees C dry bulb, 25 degrees C wet bulb). The age groups were matched on the basis of maximal O2 consumption (VO2max), body surface area, and body fatness. After heat acclimation the women walked at 40% VO2max for up to 2 h in the hot dry environment while heart rate (HR), rectal temperature (Tre), mean skin temperature (Tsk), whole-body sweating rate (Msw), and local sweating rates (msw; forearm, chest, and scapula) were measured. Additionally, the density of heat-activated sweat glands (HASG) was determined and average sweat gland flow (SGF) was calculated for the scapular area. Although no differences between age groups were found in HR response (when analyzed as percent of maximal HR) or Tsk, the older women had a significantly higher Tre throughout the heat-exercise session. The greater heat storage of the older women may be explained by their significantly lower Msw and msw. There were no differences between the younger and older women in the density of HASG after 30 min; therefore, the lower msw reflects a diminished output per HASG rather than a decrease in the number of sweat glands recruited. The diminished thermoregulatory ability of the older women, unrelated to differences in VO2max, appears to reflect either 1) a diminished response of the sweat glands to central and/or peripheral stimuli, or 2) an age-related structural alteration in the eccrine glands or surrounding skin cells.

scholarly journals Is active sweating during heat acclimation required for improvements in peripheral sweat gland function?

2009 ◽  
Vol 297 (4) ◽  
pp. R1082-R1085 ◽  
Author(s):  
Michael J. Buono ◽  
Travis R. Numan ◽  
Ryan M. Claros ◽  
Stephanie K. Brodine ◽  
Fred W. Kolkhorst
Keyword(s):  
Sweat Gland ◽  
Sweat Rate ◽  
Heat Acclimation ◽  
Whole Body ◽  
Moderate Intensity ◽  
Sweat Glands ◽  
Exercise Heart Rate ◽  
Sweat Production ◽  
Gland Function ◽  
Pilocarpine Iontophoresis

We investigated whether the eccrine sweat glands must actively produce sweat during heat acclimation if they are to adapt and increase their capacity to sweat. Eight volunteers received intradermal injections of BOTOX, to prevent neural stimulation and sweat production of the sweat glands during heat acclimation, and saline injections as a control in the contralateral forearm. Subjects performed 90 min of moderate-intensity exercise in the heat (35°C, 40% relative humidity) on 10 consecutive days. Heat acclimation decreased end-exercise heart rate (156 ± 22 vs. 138 ± 17 beats/min; P = 0.0001) and rectal temperature (38.2 ± 0.3 vs. 37.9 ± 0.3°C; P = 0.0003) and increased whole body sweat rate (0.70 ± 0.29 vs. 1.06 ± 0.50 l/h; P = 0.030). During heat acclimation, there was no measurable sweating in the BOTOX-treated forearm, but the control forearm sweat rate during exercise increased 40% over the 10 days ( P = 0.040). Peripheral sweat gland function was assessed using pilocarpine iontophoresis before and after heat acclimation. Before heat acclimation, the pilocarpine-induced sweat rate of the control and BOTOX-injected forearms did not differ (0.65 ± 0.20 vs. 0.66 ± 0.22 mg·cm−2·min−1). However, following heat acclimation, the pilocarpine-induced sweat rate in the control arm increased 18% to 0.77 ± 0.21 mg·cm−2·min−1 ( P = 0.021) but decreased 52% to 0.32 ± 0.18 mg·cm−2·min−1 ( P < 0.001) in the BOTOX-treated arm. Using complete chemodenervation of the sweat glands, coupled with direct cholinergic stimulation via pilocarpine iontophoresis, we demonstrated that sweat glands must be active during heat acclimation if they are to adapt and increase their capacity to sweat.

scholarly journals Effect of healthy aging and sex on middle cerebral artery blood velocity dynamics during moderate-intensity exercise

2018 ◽  
Vol 315 (3) ◽  
pp. H492-H501 ◽  
Author(s):  
Jaimie L. Ward ◽  
Jesse C. Craig ◽  
Yumei Liu ◽  
Eric D. Vidoni ◽  
Rebecca Maletsky ◽  
...  
Keyword(s):  
Middle Cerebral Artery ◽  
Older Women ◽  
Cerebral Artery ◽  
Blood Velocity ◽  
Moderate Intensity ◽  
Moderate Intensity Exercise ◽  
Cerebrovascular Function ◽  
Age Related ◽  
Young Subjects ◽  
Response To Exercise

Blood velocity measured in the middle cerebral artery (MCAV) increases with finite kinetics during moderate-intensity exercise, and the amplitude and dynamics of the response provide invaluable insights into the controlling mechanisms. The MCAV response after exercise onset is well fit to an exponential model in young individuals but remains to be characterized in their older counterparts. The responsiveness of vasomotor control degrades with advancing age, especially in skeletal muscle. We tested the hypothesis that older subjects would evince a slower and reduced MCAV response to exercise. Twenty-nine healthy young (25 ± 1 yr old) and older (69 ± 1 yr old) adults each performed a rapid transition from rest to moderate-intensity exercise on a recumbent stepper. Resting MCAV was lower in older than young subjects (47 ± 2 vs. 64 ± 3 cm/s, P < 0.001), and amplitude from rest to steady-state exercise was lower in older than young subjects (12 ± 2 vs. 18 ± 3 cm/s, P = 0.04), even after subjects were matched for work rate. As hypothesized, the time constant was significantly longer (slower) in the older than young subjects (51 ± 10 vs. 31 ± 4 s, P = 0.03), driven primarily by older women. Neither age-related differences in fitness, end-tidal CO2, nor blood pressure could account for this effect. Thus, MCAV kinetic analyses revealed a marked impairment in the cerebrovascular response to exercise in older individuals. Kinetic analysis offers a novel approach to evaluate the efficacy of therapeutic interventions for improving cerebrovascular function in elderly and patient populations. NEW & NOTEWORTHY Understanding the dynamic cerebrovascular response to exercise has provided insights into sex-related cerebrovascular control mechanisms throughout the aging process. We report novel differences in the kinetics response of cerebrovascular blood velocity after the onset of moderate-intensity exercise. The exponential increase in brain blood flow from rest to exercise revealed that 1) the kinetics profile of the older group was blunted compared with their young counterparts and 2) the older women demonstrated a slowed response.

scholarly journals Consumption of a High-Protein Meal Replacement Leads to Higher Fat Oxidation, Suppression of Hunger, and Improved Metabolic Profile After an Exercise Session

Nutrients ◽  
2021 ◽  
Vol 13 (1) ◽  
pp. 155
Author(s):  
Camila L. P. Oliveira ◽  
Normand G. Boulé ◽  
Aloys Berg ◽  
Arya M. Sharma ◽  
Sarah A. Elliott ◽  
...  
Keyword(s):  
Metabolic Profile ◽  
Fat Oxidation ◽  
High Protein ◽  
Whole Body ◽  
Moderate Intensity ◽  
Exercise Session ◽  
Meal Replacement ◽  
Protein Meal ◽  
High Protein Meal ◽  
The Impact

The aim of this study was to compare the impact of a high-protein meal replacement (HP-MR) versus a control (CON) breakfast on exercise metabolism. In this acute, randomized controlled, cross-over study, participants were allocated into two isocaloric arms: (a) HP-MR: 30% carbohydrate, 43% protein, and 27% fat; (b) CON: 55% carbohydrate, 15% protein, and 30% fat. Following breakfast, participants performed a moderate-intensity aerobic exercise while inside a whole-body calorimetry unit. Energy expenditure, macronutrient oxidation, appetite sensations, and metabolic blood markers were assessed. Forty-three healthy, normal-weight adults (24 males) participated. Compared to the CON breakfast, the HP-MR produced higher fat oxidation (1.07 ± 0.33 g/session; p = 0.003) and lower carbohydrate oxidation (−2.32 ± 0.98 g/session; p = 0.023) and respiratory exchange ratio (−0.01 ± 0.00; p = 0.003) during exercise. After exercise, increases in hunger were lower during the HP-MR condition. Changes in blood markers from the fasting state to post-exercise during the HP-MR condition were greater for insulin, peptide tyrosine-tyrosine, and glucagon-like peptide 1, and lower for low-density lipoprotein cholesterol, triglyceride, and glycerol. Our primary findings were that an HP-MR produced higher fat oxidation during the exercise session, suppression of hunger, and improved metabolic profile after it.

scholarly journals Increasing skeletal muscle carnitine content in older individuals increases whole‐body fat oxidation during moderate‐intensity exercise

Aging Cell ◽  
2021 ◽  
Vol 20 (2) ◽  
Author(s):  
Carolyn Chee ◽  
Chris E. Shannon ◽  
Aisling Burns ◽  
Anna L. Selby ◽  
Daniel Wilkinson ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Body Fat ◽  
Fat Oxidation ◽  
Whole Body ◽  
Moderate Intensity ◽  
Older Individuals ◽  
Moderate Intensity Exercise

Comparing the Short and Long-Term Effects of Acute Moderate-Intensity Exercise on Mnemonic Similarity and Emotional Memory Tasks

2021 ◽  
Vol 19 (1) ◽  
pp. 33-61
Author(s):  
Cesar Acevedo-Triana ◽  
Diana Cordoba-Patiño ◽  
Juan Francisco Muñoz ◽  
Julian Cifuentes ◽  
Victor Melgarejo Pinto ◽  
...  
Keyword(s):  
Undergraduate Students ◽  
Memory Task ◽  
Discrimination Performance ◽  
Rest Period ◽  
Emotional Memory ◽  
Moderate Intensity ◽  
Exercise Session ◽  
Long Term Effects ◽  
Moderate Intensity Exercise ◽  
Exercise Condition

Mounting research has linked acute moderate-intensity exercise with changes indiscrimination of similar events – i.e., mnemonic memory. Conversely, few studies have compared performance in tasks associated to each type of memory(mnemonic similarity and emotional) and less have evaluatedperformance several days after exercise sessions. Thirty-five undergraduate students were randomly distributed in three groups that differed in the assigned duration of the moderate-intensity exercise session.Weestablished first the moderate-intensityexercise program by calculating the VO2max 50%. Two-to-five days later, participantsengaged in the exercise condition to which they were assigned, followed by a five-minute rest period. Immediately after, all participantswere exposed to the training phase of both memory tasks. The first retrieval phase was tested 45 minutes afterencoding phase was completed. Subsequent retrieval phases were conducted 24, 48, and 168 hours post-training. Exercise of long duration in creased discrimination performance in images of low similarity. Comparison of the effects of exercise on discrimination of the three types of images that the emotional-memory task entailsshowed improved performance only for aversive and neutral images. Exercise improves discrimination of low similarity images, with better overall performance after a longer exercise session. This finding adds to previous reports that have found analogous effects using other memory tasks.It also supports the notion that acute effects due to exercise are specifically related to hippocampal functionality and its ability to separate patterns. Finally, maintenance of emotional information across time suggest a different mechanism,independent of pattern-separation processing.

scholarly journals The Effect of Single Bout of Acute Exercise on Working Memory Performance

2018 ◽  
Vol 3 (2) ◽  
pp. 484-487
Author(s):  
Santosh Kumar Deo ◽  
Kopila Agrawal ◽  
Prem Bhattrai ◽  
Raju Kumar Chaudhary
Keyword(s):  
Decision Making ◽  
Working Memory ◽  
Acute Exercise ◽  
Test Procedure ◽  
Step Test ◽  
Moderate Intensity ◽  
Exercise Session ◽  
Moderate Intensity Exercise ◽  
Single Bout ◽  
Back Task

Introduction: Working memory is a kind of short term memory important for reasoning and guiding decision-making and behavioral process.Objective: The goal of the present research was to study the outcome of single bout of acute moderate-intensity exercise on working memory.Methodology: Twenty two male subjects were asked to perform working memory task by 2n back task in baseline resting, immediately after exercise and after five minute of exercise session. 3 minute step test procedure was used as a moderate intensity exercise intervention.Results: The percentage correctness of 2n back task of working memory was found to be 64.36% for baseline resting condition, 78.01 % for immediately after 3-minute step test and 80.70% for 5 minute after the exercise. In both exercise session (i.e. immediately after exercise and after 5 minute of exercise), significant improvement (p value <0.05) in working memory was seen as compared to the baseline resting session while no such significant beneficial improvement was seen when compared between immediately after exercise and after 5 minute of exercise.Conclusion: Improvement in working memory after moderate exercise intervention was seen, which is important for learning and memory and decision-making.  BJHS 2018;3(2)6:484-487.

scholarly journals What Doesn't Kill you Makes you Fitter: A Systematic Review of High-Intensity Interval Exercise for Patients with Cardiovascular and Metabolic Diseases

2015 ◽  
Vol 9 ◽  
pp. CMC.S26230 ◽  
Author(s):  
Itamar Levinger ◽  
Christopher S. Shaw ◽  
Nigel K. Stepto ◽  
Samantha Cassar ◽  
Andrew J. McAinch ◽  
...  
Keyword(s):  
Systematic Review ◽  
High Intensity ◽  
Metabolic Diseases ◽  
Moderate Intensity ◽  
Exercise Session ◽  
Peak Power Output ◽  
Moderate Intensity Exercise ◽  
Interval Exercise ◽  
Cardiometabolic Diseases ◽  
High Intensity Interval

High-intensity interval exercise (HIIE) has gained popularity in recent years for patients with cardiovascular and metabolic diseases. Despite potential benefits, concerns remain about the safety of the acute response (during and/or within 24 hours postexercise) to a single session of HIIE for these cohorts. Therefore, the aim of this study was to perform a systematic review to evaluate the safety of acute HIIE for people with cardiometabolic diseases. Electronic databases were searched for studies published prior to January 2015, which reported the acute responses of patients with cardiometabolic diseases to HIIE (≥80% peak power output or ≥85% peak aerobic power, VO2peak). Eleven studies met the inclusion criteria (n = 156; clinically stable, aged 27-66 years), with 13 adverse responses reported (~8% of individuals). The rate of adverse responses is somewhat higher compared to the previously reported risk during moderate-intensity exercise. Caution must be taken when prescribing HIIE to patients with cardiometabolic disease. Patients who wish to perform HIIE should be clinically stable, have had recent exposure to at least regular moderate-intensity exercise, and have appropriate supervision and monitoring during and after the exercise session.

Age- and gender-related normative value of whole-body sagittal alignment based on 584 asymptomatic Chinese adult population from age 20 to 89

2021 ◽  
Author(s):  
Z Hu ◽  
GCW Man ◽  
KH Yeung ◽  
WH Cheung ◽  
WCW Chu ◽  
...  
Keyword(s):  
Lower Limb ◽  
Sagittal Alignment ◽  
Pearson Correlation ◽  
Age Groups ◽  
Whole Body ◽  
Normative Values ◽  
Chinese Adults ◽  
Age And Gender ◽  
Age Related ◽  
And Gender

To establish the age- and sex-related normative values of sagittal alignment in asymptomatic Chinese adults, and to investigate the changes and possible associated compensation mechanisms across age groups. 584 asymptomatic Chinese adults aged 20–89 years were recruited. Subjects were grouped according to age and gender. Whole-body standing radiographs were acquired for evaluating sagittal alignment from spine to lower limb. Sagittal parameters between gender in different age groups were compared via independent t test. Pearson correlation analysis was used to demonstrate relationships between parameters. Thoracic kyphosis (TK) increased steadily while lumbar lordosis decreased gradually in both genders. Pelvic tilt (PT) in male is greater than in female across all age groups with age related gradual increase. There were significant differences between male and female from 20s to 60s in terms of knee flexion angle (KA) and ankle dorsiflexion angle (AA), but the differences were not significant after 60s. T1 pelvic angle (TPA) was significantly correlated with spinal, pelvic and lower-limb alignment. The older group (≥50 years) had a stronger correlation of TPA with PT and KA, whereas the younger (<50 years) had stronger correlation with TK. This study comprehensively presented the normative sagittal alignment based on a large asymptomatic population, which could serve as an age- and gender-specific reference value for spine surgeons when planning for correction surgery. Age can influence the recruitment of compensation mechanism that involve more pelvic and lower limb mechanisms for elderly people.

scholarly journals Psychrometric limits and critical evaporative coefficients for exercising older women

2020 ◽  
Vol 129 (2) ◽  
pp. 263-271 ◽  
Author(s):  
W. Larry Kenney
Keyword(s):  
Older Women ◽  
Heat Balance ◽  
Moderate Intensity ◽  
Evidence Based ◽  
Moderate Intensity Exercise ◽  
Metabolic Heat ◽  
Safety Interventions ◽  
Environmental Limits ◽  
Hot Environments ◽  
Heat Events

This study is the first to describe, graphically and quantitatively, critical environmental limits for women between the ages of 62 and 80 yr based on the biophysics of heat exchange. These psychrometric limit lines define combinations of ambient temperature and humidity above which human heat balance cannot be maintained for a given metabolic heat production. These limits, and associated critical evaporative coefficients ( Ke′), can be used to model low- to moderate-intensity exercise responses in hot environments and have directly translatable data that can be used for evidence-based policy decisions, to prepare for impending heat events, and for implementation of other safety interventions.

Pulmonary oxygen uptake kinetics

2017 ◽  
Author(s):  
Alan R Barker ◽  
Neil Armstrong
Keyword(s):  
Oxygen Uptake ◽  
Oxidative Phosphorylation ◽  
Children And Adolescents ◽  
Phase Ii ◽  
Slow Component ◽  
Moderate Intensity ◽  
Heavy Exercise ◽  
Moderate Intensity Exercise ◽  
Pulmonary Oxygen Uptake ◽  
Age Related

The pulmonary oxygen uptake (pV̇O2) kinetic response to exercise provides valuable non-invasive insight into the control of oxidative phosphorylation and determinants of exercise tolerance in children and adolescents. Few methodologically robust studies have investigated pV̇O2 kinetics in children and adolescents, but age- and sex-related differences have been identified. There is a clear age-related slowing of phase II pV̇O2 kinetics during heavy and very heavy exercise, with a trend showing during moderate intensity exercise. During heavy and very heavy exercise the oxygen cost is higher for phase II and the pV̇O2 component is truncated in children. Sex-related differences occur during heavy, but not moderate, intensity exercise, with boys having faster phase II pV̇O2 kinetics and a smaller pV̇O2 slow component compared to girls. The mechanisms underlying these differences are likely related to changes in phosphate feedback controllers of oxidative phosphorylation, muscle oxygen delivery, and/or muscle fibre recruitment strategies.

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