Adequacy of Fluid Ingestion in Adolescents and Adults during Moderate-Intensity Exercise

2005 ◽  
Vol 17 (1) ◽  
pp. 41-50 ◽  
Author(s):  
Craig A. Horswill ◽  
Dennis H. Passe ◽  
John R. Stofan ◽  
Mary K. Horn ◽  
Robert Murray
Keyword(s):  
Fluid Intake ◽  
Sweat Rate ◽  
Moderate Intensity ◽  
Fluid Consumption ◽  
Maximum Heart Rate ◽  
Moderate Intensity Exercise ◽  
Fluid Ingestion ◽  
Adolescents And Adults ◽  
Voluntary Dehydration ◽  
Urine Loss

We compared ad libitum fluid consumption in adolescent (n = 15) and adult athletes (n = 34) exercising in similar environmental conditions (26.5°C, 27.3% relative humidity) and similar modes and intensities of exercise (80-85% of their age-predicted maximum heart rate). Throughout 1 hr of exercise, participants had access to sports bottles containing a sports drink (6% carbohydrate with electrolytes and identical flavoring). Sweat rate (SR) and percent dehydration were calculated from the change in body weight corrected for urine loss and fluid intake (FI). FI was significantly higher for the adults than for the adolescents. SR was also higher for the adults compared with that of the adolescents. Compared with adults, adolescents had significantly lower FI and SR, the combination of which allowed them to meet their fluid needs more closely during exercise. Minimal voluntary dehydration occurred in either group during exercise, possibly because of the nature of the exercise (noncompetitive) or the beverage characteristics (presence of sodium and sweetness) or availability of the beverage.

Differential Predictors of Adherence in Exercise Programs with Moderate versus Higher Levels of Intensity and Frequency

2005 ◽  
Vol 27 (2) ◽  
pp. 171-187 ◽  
Author(s):  
Stephen D. Anton ◽  
Michael G. Perri ◽  
Joseph Riley ◽  
William F. Kanasky ◽  
James R. Rodrigue ◽  
...  
Keyword(s):  
Exercise Program ◽  
Exercise Adherence ◽  
Moderate Intensity ◽  
Heart Rate Reserve ◽  
Maximum Heart Rate ◽  
Exercise Programs ◽  
Moderate Intensity Exercise ◽  
Daily Exercise ◽  
Participant Characteristics ◽  
Predictors Of Adherence

This study examined whether specific participant characteristics (age, sex, BMI, exercise history, and self-efficacy) differentially predicted adherence to exercise programs of moderate vs. higher levels of intensity and frequency. Sedentary adults (N = 379) were randomly assigned in a 2 × 2 design to walk 30 min/day at a frequency of either 3 to 4 days/week or 5 to 7 days/week, at an intensity of either 45–55% or 65–75% of maximum heart rate reserve. Exercise adherence was assessed via daily exercise logs completed during Months 2–6 of the exercise program. The major finding of this study was that participants with higher levels of past exercise showed better adherence to higher intensity exercise but tended to have poorer adherence to moderate intensity exercise. Our results suggest that a person’s previous experience with exercise should be considered when prescribing higher intensity exercise, and that individuals with an extensive exercise history can be prescribed higher intensity exercise.

Effects of sleep deprivation on thermoregulation during exercise

1984 ◽  
Vol 246 (1) ◽  
pp. R72-R77 ◽  
Author(s):  
M. N. Sawka ◽  
R. R. Gonzalez ◽  
K. B. Pandolf
Keyword(s):  
Sleep Deprivation ◽  
Sweat Rate ◽  
Thermal Conductance ◽  
Cycle Ergometer ◽  
Moderate Intensity ◽  
Control Test ◽  
Moderate Intensity Exercise ◽  
Ergometer Exercise ◽  
Total Body ◽  
And Control

Five fit men completed a practice, control, and sleep deprivation exercise test. Two nights of normal sleep preceded the control test, and 33 h of wakefulness preceded the sleep deprivation test. These tests consisted of 20 min of rest followed by 40 min of cycle-ergometer exercise (50% of peak O2 uptake, VO2) in a temperate (ambient temperature, 28 degrees C; relative humidity, 30%)-environment. Esophageal temperature (Tes), local sweat rate (mds), and chest thermal conductance (kch) were continuously measured. During exercise a 0.7 and 0.5 degrees C rise in Tes was found for the sleep deprivation and control tests, respectively. This increase in Tes values from rest to the end of exercise was greater (P = 0.08) for the sleep deprivation than control test. Total body sweat rate, calculated from Potter balance measurements, was 27% less (P less than 0.01) for the sleep deprivation than the control test. Both mds and kch values were lower (P less than 0.05) during the final 20 min of exercise for the sleep deprivation than control test. Final exercise mds values were 19% lower (P less than 0.05) for the sleep deprivation than control test. An asynchronous rather than a normal synchronous mds pattern was frequently observed during the sleep deprivation test. During the sleep deprivation test, the mds sensitivity (delta mds X delta Tes-1) was 38% lower (P less than 0.01) and kch sensitivity (delta kch X delta Tes-1) was 42% lower (P less than 0.05) than during the control test. These data indicate that sleep deprivation decreases evaporative and dry heat loss during moderate-intensity exercise.

Voluntary Dehydration in Runners Despite Favorable Conditions for Fluid Intake

2007 ◽  
Vol 17 (3) ◽  
pp. 284-295 ◽  
Author(s):  
Dennis Passe ◽  
Mary Horn ◽  
John Stofan ◽  
Craig Horswill ◽  
Robert Murray
Keyword(s):  
Fluid Intake ◽  
Drinking Behavior ◽  
Sweat Loss ◽  
Initial Body Weight ◽  
Self Assessment ◽  
Fluid Ingestion ◽  
Adequate Hydration ◽  
Voluntary Dehydration ◽  
Favorable Conditions ◽  
The Relationship

This study investigated the relationship between runners’ perceptions of fluid needs and drinking behavior under conditions of compensable heat stress (ambient temperature = 20.5 ± 0.7 °C, 68.9 °F; relative humidity = 76.6%). Eighteen experienced runners (15 men, 40.5 ± 2.5 y, and 3 women, 42 ± 2.3 y) were given ad libitum access to a sports drink (6% carbohydrate-electrolyte solution) at Miles 2, 4, 6, and 8. After the run (75.5 ± 8.0 min), subjects completed questionnaires that required them to estimate their individual fluid intake and sweat loss. Dehydration averaged 1.9% ± 0.8% of initial body weight (a mean sweat loss of 21.6 ± 5.1 mL·kg−1·h−1). Subjects replaced only 30.5% ± 18.1% of sweat loss and underestimated their sweat loss by 42.5% ± 36.6% (P ≤ 0.001). Subjects’ self-estimations of fluid intake (5.2 ± 3.2 mL·kg−1·h−1) were not significantly different from actual fluid intake (6.1 ± 3.4 mL·kg−1·h−1) and were significantly correlated (r = 0.63, P = 0.005). The data indicate that even under favorable conditions, experienced runners voluntarily dehydrate (P ≤ 0.001), possibly because they are unable to accurately estimate sweat loss and consequently cannot subjectively judge how much fluid to ingest to prevent dehydration. This conclusion suggests that runners should not depend on self-assessment to maintain adequate hydration, underscores the need for runners to enhance their ability to self-assess sweat losses, and suggests that a predetermined regimen of fluid ingestion might be necessary if they wish to maintain more optimal hydration.

scholarly journals The influence of angiotensin converting enzyme and bradykinin receptor B2 gene variants on voluntary fluid intake and fluid balance in healthy men during moderate-intensity exercise in the heat

2015 ◽  
Vol 40 (2) ◽  
pp. 184-190 ◽  
Author(s):  
Adora M.W. Yau ◽  
Andrew D. Moss ◽  
Lewis John James ◽  
William Gilmore ◽  
Jason J. Ashworth ◽  
...  
Keyword(s):  
Genetic Variation ◽  
Angiotensin Converting Enzyme ◽  
Body Mass ◽  
Fluid Balance ◽  
Fluid Intake ◽  
Moderate Intensity ◽  
Converting Enzyme ◽  
Moderate Intensity Exercise ◽  
Healthy Men ◽  
Bradykinin Receptor

Angiotensin converting enzyme (ACE) and bradykinin receptor B2 (B2R) genetic variation may affect thirst because of effects on angiotensin II production and bradykinin activity, respectively. To examine this, 45 healthy Caucasian men completed 60 min of cycle exercise at 62% ± 5% peak oxygen uptake in a room heated to 30.5 ± 0.3 °C with ad libitum fluid intake. Blood samples were collected pre-, mid-, and immediately post-cycle. Fluid intake, body mass loss (BML), sweat loss (determined via changes in body mass and fluid intake), and thirst sensation were recorded. All participants were genotyped for the ACE insert fragment (I) and the B2R insert sequence (P). Participants were homozygous for the wild-type allele (WW or MM), heterozygous (WI or MP) or homozygous for the insert (II or PP). No differences between genotype groups were found in mean (±SD) voluntary fluid intake (WW: 613 ± 388, WI: 753 ± 385, II: 862 ± 421 mL, p = 0.31; MM: 599 ± 322, MP: 745 ± 374, PP: 870 ± 459 mL, p = 0.20), percentage BML or any other fluid balance variables for both the ACE and B2R genes, respectively. Mean thirst perception in the B2R PP group, however, was higher (p < 0.05) than both MM and MP at 30, 45, and 60 min. In conclusion, the results of this study suggest that voluntary fluid intake and fluid balance in healthy men performing 60 min of moderate-intensity exercise in the heat are not predominantly influenced by ACE or B2R genetic variation.

Relation of Low and Moderate Intensity Exercise with Acute Mood Change in College Joggers

1998 ◽  
Vol 87 (2) ◽  
pp. 611-621 ◽  
Author(s):  
Bonnie G. Berger ◽  
David R. Owen
Keyword(s):  
Exercise Intensity ◽  
Mood States ◽  
Moderate Intensity ◽  
Profile Of Mood States ◽  
State Trait Anxiety Inventory ◽  
Maximum Heart Rate ◽  
Short Term ◽  
Moderate Intensity Exercise ◽  
Post Exercise ◽  
Before And After

This study investigated a possible relationship between exercise intensity and mood alteration that commonly is associated with physical activity. 91 college students completed the Profile of Mood States before and after 20 min. of jogging at three intensities: 55%, 75%, and 79% of age-adjusted maximum heart rate on different occasions. Exercisers also completed a demographic inventory, a Lie Scale, and the State-Trait Anxiety Inventory. Contrary to our expectations, the interaction between exercise intensity and pre-post mood benefits was not significant. Supporting the manipulation of exercise intensity, the univariate interaction between exercise intensity and pre-post exercise scores on Fatigue was significant. Joggers reported short-term mood benefits on the combined subscales of the Profile of Mood States, and each subscale contributed to the benefits. Thus, regardless of the low- or moderate-intensity, participants reported that they “felt better” after exercising.

scholarly journals The Effect of Low and Moderate Exercise on Hyperuricemia: Protocol for a Randomized Controlled Study

2021 ◽  
Vol 12 ◽  
Author(s):  
Yuning Hou ◽  
Renyan Ma ◽  
Song Gao ◽  
Keneilwe Kenny Kaudimba ◽  
Hongmei Yan ◽  
...  
Keyword(s):  
Clinical Trial ◽  
Heart Rate ◽  
Exercise Group ◽  
Moderate Intensity ◽  
Controlled Study ◽  
Control Group ◽  
Maximum Heart Rate ◽  
Moderate Intensity Exercise ◽  
Low Intensity ◽  
Low Intensity Exercise

BackgroundHyperuricemia (HUA) is a metabolic disease by purine metabolism disorders. It is a risk factor for many chronic diseases, including diabetes, hypertension, and heart disease. Studies have shown that exercise can effectively reduce serum uric acid (SUA), but the optimal exercise dose, intensity, and mode of exercise for improving HUA have not been verified in clinical studies. Therefore, this study aims to explore the effect of different exercise intensities in improving SUA of patients with HUA.Methods and AnalysisA randomized, single-blind, parallel controlled trial will be conducted in this study. 186 HUA patients who meet the inclusion criteria will be randomly divided into a 1:1:1 ratio (1): control group (2), low-intensity exercise group (brisk walking, 57-63% maximum heart rate, 150 min/week, 12 months), and (3) moderate-intensity exercise group (jogging, 64-76% maximum heart rate, 150 min/week, 12 months). The three groups of subjects will receive the same health education and prohibition of high-purine diet during the intervention period. The primary outcomes will be SUA concentration, SUA concentration change (mg/dL), SUA change rate (%), and the proportion of HUA patients. Secondary outcomes will include anthropometric parameters (body weight, waist circumference, hip circumference, BMI); physiological indicators (blood pressure, grip, vital capacity, maximum oxygen); biochemical indicators (blood lipid, blood sugar, liver enzyme, creatinine, and blood urea nitrogen). Each group of patients will go through an assessment at baseline, 3rd, 6th, and 12th months.DiscussionThis study will evaluate the effect of 12-month low-intensity exercise and moderate-intensity exercise on HUA patients. We hypothesize that both low-intensity and moderate-intensity exercise would improve HUA as compared with no-exercise control, and that moderate-intensity exercise would be more effective than low-intensity exercise in improving HUA. These results can provide a basis for the current physical activity guidelines for HUA’s healthy lifestyle management.Ethics and DisseminationThis study has been approved by the Ethical Review Committee of the Shanghai University of Sport (approval number: 102772020RT005). Informed consent will be obtained from all participants or their guardians. The authors intend to submit the study findings to peer-reviewed journals or academic conferences to be published.Clinical Trial RegistrationChinese Clinical Trial Registry, identifier ChiCTR2100042643.

scholarly journals THE SIMILAR CHANGES OF GLUCOSE LEVELS BEFORE AND AFTER MODERATE INTENSITY EXERCISE ACUTELY IN THE MORNING AND NIGHT

2020 ◽  
Vol 30 (2) ◽  
pp. 45
Author(s):  
Ronik Harsono Kamal ◽  
Kristanti Wanito Wigati ◽  
Achmad Lefi
Keyword(s):  
Blood Glucose ◽  
Physical Exercise ◽  
Asia Pacific ◽  
Moderate Intensity ◽  
Maximum Heart Rate ◽  
Moderate Intensity Exercise ◽  
Glucose Levels ◽  
Blood Glucose Levels ◽  
Before And After ◽  
The Mean

Background: There is a lot of research on the importance of exercise but studies on the effective time of exercise regarding regulation of blood glucose levels are not clearly known. Objective: This study aims to determine the comparison of changes in blood glucose levels before and after moderate intensity physical exercise in the morning and night. Material and method: Healthy men (n=34), Age between 17-22 years, Body Mass Index (BMI) between 18.5-22.9 kg/m2 (normal Asia Pacific), participating in the morning group (8.00 am) or the night group (20.00 pm) are asked to do moderate intensity physical exercise (55-70% of maximum heart rate) using ergocycle for a total of 40 minutes. Blood glucose levels 2 hours post prandial capillaries are taken before exercise and blood glucose levels after exercise are taken acutely. Result: The mean decrease in blood glucose levels in the morning group was -8.353±9.16 mg/dL and in the night group was -6.294±10.10 mg/dL. Blood glucose levels decreased significantly for the morning group (p=0.002) and the night group (p=0.021). The comparison of changes in blood glucose levels between the morning and night groups was not significant (p=0.538). Conclusion: There is no difference between morning or night exercise related to changes in blood glucose levels.

Temperature of Ingested Water and Thermoregulation During Moderate-Intensity Exercise

1997 ◽  
Vol 22 (5) ◽  
pp. 479-493 ◽  
Author(s):  
Gregory S. Wimer ◽  
David R. Lamb ◽  
William M. Sherman ◽  
Scott C. Swanson
Keyword(s):  
Blood Flow ◽  
Cold Water ◽  
Sweat Rate ◽  
Fluid Replacement ◽  
Whole Body ◽  
Moderate Intensity ◽  
Moderate Intensity Exercise ◽  
Radiative Heat Loss ◽  
Trained Subjects ◽  
Water Ingestion

The effect of the temperature of ingested water on the rise in core temperature (TCO) during exercise is not clear. Seven trained subjects were recruited to complete 2 hr of recumbent cycling at 51% VO2 peak in a temperate environment (Ta = 26 °C, relative humidity = 40%) on four occasions, while ingesting either no fluid (trial NF26), cold water (0.5 °C; trial CD26), cool water (19 °C; trial CL26), or warm water (38 °C; trial WA26) during the second hour of exercise. A fifth trial was conducted during which convective and radiative heat loss were reduced by raising Ta to 31 °C. During this trial, subjects ingested cold water (0.5 °C; trial CD31). When compared to WA26, over the second hour of exercise, CD26 attenuated the time-averaged changes in (TCO) and forearm blood flow and decreased whole-body sweat rate and forearm sweat rate (p < .05). Similarly, relative to WA26, the CL26 trial attenuated the time-averaged changes in TCO and reduced whole-body sweat rate (p < .05) during the second hour of exercise, but CL26 had no significant effect on forearm sweat rate or blood flow. Finally, regardless of beverage temperature, water ingestion (vs. NF26) reduced the time-averaged changes in TCO and in heat storage during the second hour of exercise (p < .05). Key words: exertion, temperature regulation, skin blood flow, body temperatures, fluid replacement

Influence of Beverage Temperature on Palatability and Fluid Ingestion During Endurance Exercise: A Systematic Review

2012 ◽  
Vol 22 (3) ◽  
pp. 199-211 ◽  
Author(s):  
Catriona A. Burdon ◽  
Nathan A. Johnson ◽  
Phillip G. Chapman ◽  
Helen T. O’Connor
Keyword(s):  
Systematic Review ◽  
Body Weight ◽  
Fluid Intake ◽  
Meta Analysis ◽  
Drinking Behavior ◽  
Hydration Status ◽  
Heat Illness ◽  
Fluid Consumption ◽  
Fluid Ingestion ◽  
Human Participants

Beverage palatability is known to influence fluid consumption during exercise and may positively influence hydration status and help prevent fatigue, heat illness, and decreased performance.Purpose:The aims of this review were to evaluate the effect of beverage temperature on fluid intake during exercise and investigate the influence of beverage temperature on palatability.Methods:Citations from multiple databases were searched from the earliest record to November 2010 using the terms beverage, fluid, or water and palatability, preference, feeding, and drinking behavior and temperature. Included studies (N = 14) needed to use adult (≥18 yr) human participants, have beverage temperatures ≤50 °C, and measure consumption during exercise and/or palatability.Results:All studies reporting palatability (n = 10) indicated that cold (0–10 °C) or cool (10–22 °C) beverages were preferred to warmer ones (control, ≥22 °C). A meta-analysis on studies reporting fluid consumption (n = 5) revealed that participants consumed ~50% (effect size = 1.4, 0.75–2.04, 95% CI) more cold/cool beverages than control during exercise. Subanalysis of studies assessing hydration status (n = 4) with consumption of cool/cold vs. warm beverages demonstrated that dehydration during exercise was reduced by 1.3% of body weight (1.6–0.9%, 95% CI; p < .001).Conclusion:Cool beverage temperatures (<22 °C) significantly increased fluid palatability, fluid consumption, and hydration during exercise vs. control (≥22 °C).

scholarly journals THE SIMILAR CHANGES OF GLUCOSE LEVELS BEFORE AND AFTER MODERATE INTENSITY EXERCISE ACUTELY IN THE MORNING AND EVENING

2020 ◽  
Vol 30 (2) ◽  
pp. 39
Author(s):  
Ronik Harsono Kamal ◽  
Kristanti Wanito Wigati ◽  
Achmad Lefi
Keyword(s):  
Blood Glucose ◽  
Physical Exercise ◽  
Asia Pacific ◽  
Moderate Intensity ◽  
Maximum Heart Rate ◽  
Moderate Intensity Exercise ◽  
Glucose Levels ◽  
Blood Glucose Levels ◽  
Before And After ◽  
The Mean

Background: There is a lot of research on the importance of exercise but studies on the effective time of exercise regarding regulation of blood glucose levels are not clearly known. Objective: This study aimed to determine the comparison of changes in blood glucose levels before and after moderate intensity physical exercise in the morning and evening. Materials and Methods: Healthy men (n=34), age between 17-22 years, Body Mass Index (BMI) between 18.5-22.9 kg/m2 (normal Asia Pacific), participating in the morning (8.00 am) or evening group (20.00 pm) are asked to do moderate intensity physical exercise (55-70% of maximum heart rate) using ergocycle for a total of 40 minutes. Blood glucose levels 2 hours post prandial capillaries were taken before exercise and blood glucose levels after exercise were taken acutely. Results: The mean decrease in blood glucose levels in the morning group was ± 8.353 ± 9.16 mg/dL and in the evening group was ± 6.294 ± 10.10 mg/dL. Blood glucose levels decreased significantly for the morning group (p=0.002) and the evening group (p=0.021). The comparison of changes in blood glucose levels between the morning and evening groups was not significant (p=0.538). Conclusion: There was no difference between morning or evening exercise related to changes in blood glucose levels.

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