30 research outputs found

    Fluid movement and availability following ingestion of glucose solutions at rest and after exercise

    Get PDF
    The consequences of ingesting different carbohydrate solutions on fluid movement and availability have not been systematically examined. In addition, the role of carbohydrate in the post-exercise rehydration period has received little attention despite the need for substrate replenishment following exercise and the role of carbohydrates in stimulating water absorption in the intestine. The aims of this thesis were to assess fluid absorption characteristics and availability of solutions containing increasing concentrations of glucose and to evaluate their role in the restoration and maintenance of fluid balance following a period of exercise-induced dehydration. The ingestion of a single bolus of a commercially available hypertonic 18% carbohydrate solution (chapter 3) and a hypertonic 10% glucose solution (chapter 4) resulted in reductions in plasma volume that are most likely due to acute net secretion of water into the intestinal lumen. When investigating recovery of whole body hydration status after sweat loss, a hypertonic 10% glucose-electrolyte solution maintained whole body fluid balance for a longer period than a hypotonic 2% glucose-electrolyte solution and an electrolyte only solution when a fixed volume of fluid was consumed during a rehydration period of one hour following cycle exercise in the heat (chapter 5). When fluid was consumed ad libitum over a two hour period following similar cycle exercise in the heat, a hypertonic 10% glucose-electrolyte solution was as effective in restoring and maintaining fluid balance as a 2% hypotonic glucose-electrolyte solution and an electrolyte only solution (chapter 6). The reduced rate of gastric emptying that accompanies the ingestion of high carbohydrate solutions was likely to be the primary cause for the difference in urine production reported between thetrials during this study (chapter 7). In conclusion, ingestion of hypertonic carbohydrate solutions results in a reduction in extracellular fluid volume that is most likely due to secretion of water into the intestinal lumen and the carbohydrate content of an ingested solution is of importance in the post-exercise rehydration period.EThOS - Electronic Theses Online ServiceGBUnited Kingdo

    A Comparison of Intermittent and Continuous Exercise Bouts at Different Intensities on Appetite and Postprandial Metabolic Responses in Healthy Men

    Get PDF
    Exercise intensity affects many potential postprandial responses, but there is limited information on the influence of exercise modality. Therefore, the aim of this study was to investigate if the nature of exercise at two different intensities would affect gastric emptying rate (GER), appetite and metabolic responses following ingestion of a semi-solid meal. Twelve healthy men completed, in a random order, four 60-min cycles at 60% VO2peak (MOD), 40% VO2peak (LOW) and in a continuous (CON) or intermittent (INT) manner. INT consisted of 20 × 1-min exercise bouts with 2-min rest breaks. INT and CON were matched for total work output at each intensity. GER of the post-exercise meal was measured for 2 h using the 13C-breath method. Blood glucose, substrate utilisation and appetite ratings were measured at regular intervals throughout all trials and 24-h energy intake (EI) post-trials was assessed. GER-Delta over Baseline (DOB) was lower (p 0.05). 24-h post-trial EI was similar between LOW-CON vs. LOW-INT (p > 0.05), although MOD-INT vs. MOD-CON 3500 ± 1419 vs. 2556 ± 989 kCal: p < 0.001 was elevated. In summary, MOD-INT exercise delays GER without stimulating perceived appetite in the 2 h period after meal ingestion, although EI was greater in the 24-h post-trial

    The Effect of Glucose or Fructose Added to a Semi-solid Meal on Gastric Emptying Rate, Appetite, and Blood Biochemistry

    Get PDF
    The ingestion of fructose is of interest due to previously reported differences in gastrointestinal, appetite, and metabolic effects when compared to glucose ingestion when ingested in liquid solution. The aim of this study was to examine these variables when fructose and glucose are added to a semi-solid meal. Seven healthy male participants completed three experimental trials involving the ingestion of 300 mL of semi-skimmed milk mixed with 40 g of instant porridge mix (CON) and with the addition of either 40 g of glucose (GLU) or fructose (FRU). Subjective feelings of appetite were assessed for 2 h after ingestion with blood samples collected at regular intervals. Gastric emptying rate was assessed using the 13C breath test method. Half emptying time was not different between trials (CON = 159 ± 51 min; GLU = 197 ± 46 min; FRU = 198 ± 67 min: P = 0.117). No differences were observed for any subjective measurements of appetite (P &gt; 0.05) while blood glucose was elevated (P &lt; 0.05) 20 min after ingestion on both GLU and FRU with this tending to be higher on GLU than FRU. FRU resulted in greater (P &lt; 0.05) blood lactate concentrations than on the other trials. The results of this study demonstrate that gastric emptying rate of glucose and fructose is similar when ingested in a semi-solid meal. In addition, there is little difference in appetite response between these sugars, however, there are some differences in metabolic response which deserve further study

    Diurnal influences of fasted and non-fasted brisk walking on gastric emptying rate, metabolic responses, and appetite in healthy males

    Get PDF
    Growing evidence suggests circadian rhythms, nutrition and metabolism are intimately linked. Intermittentfasting (IMF) has become an increasingly popular intervention for metabolic health and combining IMF withexercise may lead to benefits for weight management. However, little is known about the diurnal variation offasted exercise. This study aimed to investigate the diurnal influences on gastric emptying rate (GER), metabolicresponses, and appetite to fasted and non-fasted exercise. Twelve healthy males completed four 45 min walks ina randomised order. Walks were completed in the morning (AM) and evening (PM) and either fasted (FASTED)or after consumption of a standardised meal (FED). GER of a semi-solid lunch was subsequently measured for 2 husing the13C breath test. Blood glucose concentration, substrate utilisation, and ratings of appetite were mea-sured throughout. Energy intake was also assessed for the following 24 h. GER Tlagwas slower in PM-FASTEDcompared to AM-FASTED, AM-FED, and PM-FED (75 ± 18 min vs. 63 ± 14 min,P= 0.001, vs. 65 ± 10 min,P= 0.028 and vs. 67 ± 16 min,P= 0.007). Blood glucose concentration was greater in the FED trials incomparison to the FASTED trials pre-lunch (P 0.05) or 24 h post-energy intake (P= 0.476). Thesefindings suggest that evening fasted exercise results in delayed GER, withoutchanges in appetite. No compensatory effects were observed for appetite, and 24 h post-energy intake for bothfasted exercise trials, therefore, increased fat oxidation holds positive implications for weight management

    Optimizing the restoration and maintenance of fluid balance after exercise-induced dehydration

    Get PDF
    Hypohydration, or a body water deficit, is a common occurrence in athletes and recreational exercisers following the completion of an exercise session. For those who will undertake a further exercise session that day, it is important to replace water losses to avoid beginning the next exercise session hypohydrated and the potential detrimental effects on performance that this may lead to. The aim of this review is to provide an overview of the research related to factors that may affect post-exercise rehydration. Research in this area has focused on the volume of fluid to be ingested, the rate of fluid ingestion and on fluid composition. Volume replacement during recovery should exceed that lost during exercise to allow for ongoing water loss however ingestion of large volumes of plain water results in a prompt diuresis, effectively preventing longer term maintenance of water balance. Addition of sodium to a rehydration solution is beneficial for maintenance of fluid balance due to its effect on extracellular fluid osmolality and volume. The addition of macronutrients, such as carbohydrate and protein, can promote maintenance of hydration by influencing absorption and distribution of ingested water which, in turn, effects extracellular fluid osmolality and volume. Alcohol is commonly consumed in the post-exercise period and may influence post-exercise rehydration as will the co-ingestion of food. Future research in this area should focus on providing information related to optimal rates of fluid ingestion, advisable solutions to ingest during different duration recovery periods and confirmation of mechanistic explanations for the observations outlined

    A Pilot Study Investigating the Influence of Glucagon-Like Peptide-1 Receptor Single Nucleotide Polymorphisms on Gastric Emptying Rate in Caucasian Men

    Get PDF
    Gastric emptying rate in humans is subject to large individual variability, but previous research on the influence of genetics is scarce. Variation in the glucagon-like peptide-1 receptor (GLP1R) gene is a plausible candidate gene to partially explain the high variance. This study aimed to investigate the influence of genetic variation in the GLP1R gene on gastric emptying rate of a glucose solution in humans. Forty eight healthy Caucasian males took part in this investigation. Gastric emptying rate of a 6% glucose solution was assessed using the 13C breath test method and a venous blood sample was obtained from each participant. Participants were genotyped for 27 Tag single nucleotide polymorphisms (SNPs) in the GLP1R locus using Sequenom MassARRAY iPLEX GOLD analysis and MALDI-TOF mass spectrometry. The time at which maximal emptying rate occurred (Tlag) was faster in participants with the CC genotype than in TT and TC genotypes for SNP rs742764: [median (quartiles) CC, 35 (30–36) min vs. TT, 43 (39–46) min, and TC, 41 (39–45) min; P &lt; 0.01]. Tlag was also slower in participants with the AA genotype compared to the TT and TA genotypes for SNP rs2254336: [AA, 43 (39–49) min vs. TT, 36 (34–41) min, and TA, 39 (35–42) min; P &lt; 0.05]. Analysis by phenotype also showed differences in half-emptying time (T12) and Tlag for SNPs rs9283907, rs2268657, and rs2254336. Several neighboring Tag SNPs within the GLP1R gene were found to be associated with gastric emptying rate, and should be further investigated

    Development and Validation of the Behavioral Tendencies Questionnaire

    Get PDF
    At a fundamental level, taxonomy of behavior and behavioral tendencies can be described in terms of approach, avoid, or equivocate (i.e., neither approach nor avoid). While there are numerous theories of personality, temperament, and character, few seem to take advantage of parsimonious taxonomy. The present study sought to implement this taxonomy by creating a questionnaire based on a categorization of behavioral temperaments/tendencies first identified in Buddhist accounts over fifteen hundred years ago. Items were developed using historical and contemporary texts of the behavioral temperaments, described as “Greedy/Faithful”, “Aversive/Discerning”, and “Deluded/Speculative”. To both maintain this categorical typology and benefit from the advantageous properties of forced-choice response format (e.g., reduction of response biases), binary pairwise preferences for items were modeled using Latent Class Analysis (LCA). One sample (n1 = 394) was used to estimate the item parameters, and the second sample (n2 = 504) was used to classify the participants using the established parameters and cross-validate the classification against multiple other measures. The cross-validated measure exhibited good nomothetic span (construct-consistent relationships with related measures) that seemed to corroborate the ideas present in the original Buddhist source documents. The final 13-block questionnaire created from the best performing items (the Behavioral Tendencies Questionnaire or BTQ) is a psychometrically valid questionnaire that is historically consistent, based in behavioral tendencies, and promises practical and clinical utility particularly in settings that teach and study meditation practices such as Mindfulness Based Stress Reduction (MBSR)

    Mortality and pulmonary complications in patients undergoing surgery with perioperative SARS-CoV-2 infection: an international cohort study

    Get PDF
    Background: The impact of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) on postoperative recovery needs to be understood to inform clinical decision making during and after the COVID-19 pandemic. This study reports 30-day mortality and pulmonary complication rates in patients with perioperative SARS-CoV-2 infection. Methods: This international, multicentre, cohort study at 235 hospitals in 24 countries included all patients undergoing surgery who had SARS-CoV-2 infection confirmed within 7 days before or 30 days after surgery. The primary outcome measure was 30-day postoperative mortality and was assessed in all enrolled patients. The main secondary outcome measure was pulmonary complications, defined as pneumonia, acute respiratory distress syndrome, or unexpected postoperative ventilation. Findings: This analysis includes 1128 patients who had surgery between Jan 1 and March 31, 2020, of whom 835 (74·0%) had emergency surgery and 280 (24·8%) had elective surgery. SARS-CoV-2 infection was confirmed preoperatively in 294 (26·1%) patients. 30-day mortality was 23·8% (268 of 1128). Pulmonary complications occurred in 577 (51·2%) of 1128 patients; 30-day mortality in these patients was 38·0% (219 of 577), accounting for 81·7% (219 of 268) of all deaths. In adjusted analyses, 30-day mortality was associated with male sex (odds ratio 1·75 [95% CI 1·28–2·40], p\textless0·0001), age 70 years or older versus younger than 70 years (2·30 [1·65–3·22], p\textless0·0001), American Society of Anesthesiologists grades 3–5 versus grades 1–2 (2·35 [1·57–3·53], p\textless0·0001), malignant versus benign or obstetric diagnosis (1·55 [1·01–2·39], p=0·046), emergency versus elective surgery (1·67 [1·06–2·63], p=0·026), and major versus minor surgery (1·52 [1·01–2·31], p=0·047). Interpretation: Postoperative pulmonary complications occur in half of patients with perioperative SARS-CoV-2 infection and are associated with high mortality. Thresholds for surgery during the COVID-19 pandemic should be higher than during normal practice, particularly in men aged 70 years and older. Consideration should be given for postponing non-urgent procedures and promoting non-operative treatment to delay or avoid the need for surgery. Funding: National Institute for Health Research (NIHR), Association of Coloproctology of Great Britain and Ireland, Bowel and Cancer Research, Bowel Disease Research Foundation, Association of Upper Gastrointestinal Surgeons, British Association of Surgical Oncology, British Gynaecological Cancer Society, European Society of Coloproctology, NIHR Academy, Sarcoma UK, Vascular Society for Great Britain and Ireland, and Yorkshire Cancer Research
    corecore