scholarly journals Pre-Exercise Carbohydrate or Protein Ingestion Influences Substrate Oxidation but Not Performance or Hunger Compared with Cycling in the Fasted State

Nutrients ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 1291
Author(s):  
Jeffrey A. Rothschild ◽  
Andrew E. Kilding ◽  
Sophie C. Broome ◽  
Tom Stewart ◽  
John B. Cronin ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Perceived Exertion ◽  
Ventilatory Threshold ◽  
Average Power ◽  
Fat Oxidation ◽  
Fasted State ◽  
Protein Ingestion ◽  
The Difference ◽  
And Performance ◽  
Protein Rich

Nutritional intake can influence exercise metabolism and performance, but there is a lack of research comparing protein-rich pre-exercise meals with endurance exercise performed both in the fasted state and following a carbohydrate-rich breakfast. The purpose of this study was to determine the effects of three pre-exercise nutrition strategies on metabolism and exercise capacity during cycling. On three occasions, seventeen trained male cyclists (VO2peak 62.2 ± 5.8 mL·kg−1·min−1, 31.2 ± 12.4 years, 74.8 ± 9.6 kg) performed twenty minutes of submaximal cycling (4 × 5 min stages at 60%, 80%, and 100% of ventilatory threshold (VT), and 20% of the difference between power at the VT and peak power), followed by 3 × 3 min intervals at 80% peak aerobic power and 3 × 3 min intervals at maximal effort, 30 min after consuming a carbohydrate-rich meal (CARB; 1 g/kg CHO), a protein-rich meal (PROTEIN; 0.45 g/kg protein + 0.24 g/kg fat), or water (FASTED), in a randomized and counter-balanced order. Fat oxidation was lower for CARB compared with FASTED at and below the VT, and compared with PROTEIN at 60% VT. There were no differences between trials for average power during high-intensity intervals (367 ± 51 W, p = 0.516). Oxidative stress (F2-Isoprostanes), perceived exertion, and hunger were not different between trials. Overall, exercising in the overnight-fasted state increased fat oxidation during submaximal exercise compared with exercise following a CHO-rich breakfast, and pre-exercise protein ingestion allowed similarly high levels of fat oxidation. There were no differences in perceived exertion, hunger, or performance, and we provide novel data showing no influence of pre-exercise nutrition ingestion on exercise-induced oxidative stress.

Increased Cardiorespiratory Stress During Submaximal Cycling After Ketone Monoester Ingestion in Endurance-Trained Adults

2021 ◽  
Author(s):  
Devin Goddard McCarthy ◽  
William Bostad ◽  
Fiona Jane Powley ◽  
Jonathan P. Little ◽  
Douglas Richards ◽  
...  
Keyword(s):  
Body Mass ◽  
Ketone Body ◽  
Perceived Exertion ◽  
Bolus Dose ◽  
Ventilatory Threshold ◽  
Time Trial ◽  
Rating Of Perceived Exertion ◽  
Threshold Intensity ◽  
Double Blind ◽  
And Performance

There is growing interest in the effect of exogenous ketone body supplementation on exercise responses and performance. The limited studies to date have yielded equivocal data, likely due in part to differences in dosing strategy, increase in blood ketones, and participant training status. Using a randomized, double-blind, counterbalanced design, we examined the effect of ingesting a ketone monoester (KE) supplement (600 mg/kg body mass) or flavour-matched placebo in endurance-trained adults (n=10 males, n=9 females; VO2peak=57±8 ml/kg/min). Participants performed a 30-min cycling bout at ventilatory threshold intensity (71±3% VO2peak), followed 15 min later by a 3 kJ/kg body mass time-trial. KE versus placebo ingestion increased plasma [β-hydroxybutyrate] before exercise (3.9±1.0 vs 0.2±0.3 mM, p<0.0001, dz=3.4), ventilation (77±17 vs 71±15 L/min, p<0.0001, dz=1.3) and heart rate (155±11 vs 150±11 beats/min, p<0.001, dz=1.2) during exercise, and rating of perceived exertion at the end of exercise (15.4±1.6 vs 14.5±1.2, p<0.01, dz=0.85). Plasma [β-hydroxybutyrate] remained higher after KE vs placebo ingestion before the time-trial (3.5±1.0 vs 0.3±0.2 mM, p<0.0001, dz=3.1), but performance was not different (KE: 16:25±2:50 vs placebo: 16:06±2:40 min:s, p=0.20; dz=0.31). We conclude that acute ingestion of a relatively large KE bolus dose increased markers of cardiorespiratory stress during submaximal exercise in endurance-trained participants. Novelty bullets: •Limited studies have yielded equivocal data regarding exercise responses after acute ketone body supplementation. •Using a randomized, double-blind, placebo-controlled, counterbalanced design, we found that ingestion of a large bolus dose of a commercial ketone monoester supplement increased markers of cardiorespiratory stress during cycling at ventilatory threshold intensity in endurance-trained adults.

scholarly journals The effect of low- vs high-cadence interval training on the freely chosen cadence and performance in endurance-trained cyclists

2016 ◽  
Vol 41 (6) ◽  
pp. 666-673 ◽  
Author(s):  
Anthony G. Whitty ◽  
Aron J. Murphy ◽  
Aaron J. Coutts ◽  
Mark L. Watsford
Keyword(s):  
Perceived Exertion ◽  
Average Power ◽  
Time Trial ◽  
Interval Training ◽  
Performance Measure ◽  
Rating Of Perceived Exertion ◽  
Superior Performance ◽  
Strength Development ◽  
And Performance ◽  
High Cadence

The aim of this study was to determine the effects of high- and low-cadence interval training on the freely chosen cadence (FCC) and performance in endurance-trained cyclists. Sixteen male endurance-trained cyclists completed a series of submaximal rides at 60% maximal power (Wmax) at cadences of 50, 70, 90, and 110 r·min−1, and their FCC to determine their preferred cadence, gross efficiency (GE), rating of perceived exertion, and crank torque profile. Performance was measured via a 15-min time trial, which was preloaded with a cycle at 60% Wmax. Following the testing, the participants were randomly assigned to a high-cadence (HC) (20% above FCC) or a low-cadence (LC) (20% below FCC) group for 18 interval-based training sessions over 6 weeks. The HC group increased their FCC from 92 to 101 r·min−1 after the intervention (p = 0.01), whereas the LC group remained unchanged (93 r·min−1). GE increased from 22.7% to 23.6% in the HC group at 90 r·min−1 (p = 0.05), from 20.0% to 20.9% at 110 r·min−1 (p = 0.05), and from 22.8% to 23.2% at their FCC. Both groups significantly increased their total distance and average power output following training, with the LC group recording a superior performance measure. There were minimal changes to the crank torque profile in both groups following training. This study demonstrated that the FCC can be altered with HC interval training and that the determinants of the optimal cycling cadence are multifactorial and not completely understood. Furthermore, LC interval training may significantly improve time-trial results of short duration as a result of an increase in strength development or possible neuromuscular adaptations.

scholarly journals The Effects of Acute Ingestion of a High-fat Solution, compared to a High-Carbohydrate Solution, on Skeletal Muscle Oxygenation, Fat Oxidation and Performance During a 2-hour Cycling Effort Followed by a Short Time Trial in Cyclists and Triathletes

2021 ◽  
Vol 3 (122) ◽  
pp. 42-58
Author(s):  
Antoine Jolicoeur Desroches ◽  
Frédéric Domingue ◽  
Louis Laurencelle ◽  
Claude Lajoie
Keyword(s):  
Skeletal Muscle ◽  
Perceived Exertion ◽  
Near Infrared ◽  
Time Trial ◽  
Fat Oxidation ◽  
Muscle Oxygenation ◽  
Skeletal Muscle Oxygenation ◽  
And Performance ◽  
Maximal Effort ◽  
Carbohydrate Solution

This study aimed to determine the effects of consuming a high fat solution (HFS) compared to a high carbohydrate solution (HCS) during a cycling effort on substrate oxidation, muscle oxygenation and performance with cyclists and triathletes. Thirteen men participated in this study (age: 30.4 ± 6.3 y; height: 178.7 ± 6.1 cm; weight: 74.9 ± 6.5 kg; V̇O2 peak: 60.5 ± 7.9 mlO2×kg-1×min-1). The solutions were isocaloric (total of 720 kcal) and were consumed every 20 minutes. Each solution of HFS contained 12.78 g of lipids, 1.33 g of carbohydrates and 0.67 g of proteins, and each solution of HCS contained 28 g of carbohydrates. We measured pulmonary oxygen consumption and skeletal muscle oxygenation, using a Near Infrared Spectrometer (NIRS) during a cycling effort consisting of 2 hours at 65 % of maximal aerobic power (MAP) followed immediately by a 3-minute time-trial (TT). We observed that the consumption of the HFS increased the rate of fat oxidation at the end of the sub-maximal effort (0.61 ± 0.14 vs 0.53 ± 0.17 g×min-1, p < 0.05). We have also shown that the HFS negatively affected the performance in the TT (mean Watts: HCS: 347.0 ± 77.4 vs HFS: 326.5 ± 88.8 W; p < 0.05) and the rating of perceived exertions during the sub-maximal effort (modified Borg Perceived Exertion scale: 1–10) (mean: 3.62 ± 0.58 for HCS vs 4.16 ± 0.62 for HFS; p < 0.05). We did not observe a significant effect of the acute consumption of the HFS compared to the HCS on muscle oxygenation during the cycling effort. Finally, we observed that cyclists who demonstrated a high skeletal muscle deoxygenation relative to their pulmonary oxygen consumption (DHHb/V̇O2) had a higher fat oxidation capacity (higher Fatmax). In conclusion, even though the consumption of HFS increased the rate of fat oxidation at the end of a sub-maximal effort, it did not affect muscle oxygenation and it negatively affected performance and perceived exertion during a time-trial and caused gastro-intestinal distress in some participants. Keywords: Fat oxidation, Skeletal muscle oxygenation, Lipid supplementation, Carbohydrate supplementation, Near Infrared Spectroscopy (NIRS), Cycling, Triathlon.

A Modification of the Payne-Jones Method of Identifying Abnormal Differences in WISC-R Performance and Verbal IQ's

1996 ◽  
Vol 12 (1) ◽  
pp. 27-32 ◽  
Author(s):  
Louis M. Hsu
Keyword(s):  
Full Scale ◽  
True Score ◽  
Verbal Iq ◽  
Score Difference ◽  
The Difference ◽  
And Performance

The difference (D) between a person's Verbal IQ (VIQ) and Performance IQ (PIQ) has for some time been considered clinically meaningful ( Kaufman, 1976 , 1979 ; Matarazzo, 1990 , 1991 ; Matarazzo & Herman, 1985 ; Sattler, 1982 ; Wechsler, 1984 ). Particularly useful is information about the degree to which a difference (D) between scores is “abnormal” (i.e., deviant in a standardization group) as opposed to simply “reliable” (i.e., indicative of a true score difference) ( Mittenberg, Thompson, & Schwartz, 1991 ; Silverstein, 1981 ; Payne & Jones, 1957 ). Payne and Jones (1957) proposed a formula to identify “abnormal” differences, which has been used extensively in the literature, and which has generally yielded good approximations to empirically determined “abnormal” differences ( Silverstein, 1985 ; Matarazzo & Herman, 1985 ). However applications of this formula have not taken into account the dependence (demonstrated by Kaufman, 1976 , 1979 , and Matarazzo & Herman, 1985 ) of Ds on Full Scale IQs (FSIQs). This has led to overestimation of “abnormality” of Ds of high FSIQ children, and underestimation of “abnormality” of Ds of low FSIQ children. This article presents a formula for identification of abnormal WISC-R Ds, which overcomes these problems, by explicitly taking into account the dependence of Ds on FSIQs.

Evaluation of Salivary Antioxidants and Oxidative Stress Markers in Type 2 Diabetes Mellitus: A Retrospective Cohort Study

2020 ◽  
Vol 20 (4) ◽  
pp. 584-590 ◽  
Author(s):  
Shima Fathi ◽  
Shiva Borzouei ◽  
Mohammad Taghi Goodarzi ◽  
Jalal Poorolajal ◽  
Fatemeh Ahmadi-Motamayel
Keyword(s):  
Oxidative Stress ◽  
Diabetes Mellitus ◽  
Control Group ◽  
Oxidative Stress Markers ◽  
Stress Markers ◽  
Type 2 Dm ◽  
Patients With Diabetes ◽  
The Difference ◽  
And Oxidative Stress

Background: Diabetes Mellitus (DM) is a progressive metabolic disorder. Objective: The aim of this study was to investigate the relationship between antioxidant and oxidative stress markers in the saliva of patients with type 2 DM and a healthy control group. Methods: In this study, 20 patients with diabetes and 20 healthy individuals were evaluated. Salivary antioxidants markers consisted of total antioxidant capacity (TAC), uric acid (UA), peroxidase and catalase. Oxidative stress markers included total oxidant status (TOS), malondealdehyde (MDA) and total thiol (SH). Sialochemical analysis was performed with spectrophotometric assay. All the statistical analyses were conducted using STATA software. Results: TAC decreased significantly in patients with diabetes. Although salivary UA and peroxidase were lower in patients with diabetes compared to the control group, the difference was not significant. Salivary catalase in patients with diabetes was significantly lower than that in the control group. MDA and TOS exhibited significantly higher levels in type 2 DM. SH levels were slightly higher in DM. Conclusions: According to the results of the present study, there were some changes in the salivary levels of some antioxidants and oxidative stress markers in patients with type 2 DM and could be measured as an indicator of serum changes..

scholarly journals Acute Effects of Different Postactivation Potentiation Protocols on Traditional Rowing Performance

2020 ◽  
Vol 18 (1) ◽  
pp. 80
Author(s):  
Alfonso Penichet-Tomas ◽  
Jose M. Jimenez-Olmedo ◽  
Luis Serra Torregrosa ◽  
Basilio Pueo
Keyword(s):  
Effect Size ◽  
Muscle Power ◽  
Average Power ◽  
Postactivation Potentiation ◽  
Warm Up ◽  
Maximal Load ◽  
Rowing Performance ◽  
Load Intensity ◽  
And Performance ◽  
Student’S T

Postactivation potentiation (PAP) describes an initial muscular activation with a submaximal or maximal load intensity that produces acute improvements in muscle power and performance in subsequent explosive activities. The objective of this study was to compare the effect of different PAP protocols in rowing performance. A crossover design involving seven rowers was used, in which two different PAP protocols were applied: PAP of maximal conditioning contractions (PAP MCC) on a rowing ergometer to provide greater transferability and, thus, enhance the magnitude of PAP stimuli on subsequent rowing performance; and PAP of maximal strength contractions (PAP MSC) in half squat and bench pull exercises, similar to the main exercises in rowing strength training, to perform a 20 s “all-out” test simulating a competition start. Student’s t-test was used to compare means of the variables (p < 0.05). Effect size statistics were calculated using Cohen’s d. The PAP MCC protocol resulted in significant differences, with an extremely large effect size in average power output (p = 0.034, d = 0.98) in the first 3 (p = 0.019, d = 1.15) and first 5 (p = 0.036, d = 0.91) strokes. This group also reached a greater number of strokes (p = 0.049, d = 2.29) and strokes per minute (p = 0.046, d = 1.15). PAP with maximal conditioning contractions in rowing warm-up enhanced subsequent rowing sprint and is an advisable strategy to potentiate performance at the start of rowing competitions and sprint regattas.

scholarly journals Acute Effects of Caffeine Intake on Psychological Responses and High-Intensity Exercise Performance

2021 ◽  
Vol 18 (2) ◽  
pp. 584
Author(s):  
Raúl Domínguez ◽  
Pablo Veiga-Herreros ◽  
Antonio Jesús Sánchez-Oliver ◽  
Juan José Montoya ◽  
Juan José Ramos-Álvarez ◽  
...  
Keyword(s):  
Perceived Exertion ◽  
Mood State ◽  
Average Power ◽  
Test Methods ◽  
Wingate Test ◽  
Maximum Power ◽  
Caffeine Intake ◽  
Psychological Responses ◽  
Subjective Vitality ◽  
Positive Effects

Objective: The aim of this study was to investigate the effects of caffeine supplementation on: (i) psychological responses of subjective vitality and mood; (ii) performance through a Wingate test; and (iii) rate of perceived exertion (RPE) reported after a Wingate test. Methods: Fifteen male participants (22.60 ± 2.16 years) ingested 6 mg·kg-1 of caffeine or placebo (sucrose) supplementation in two experimental sessions. After 60 min from supplement intake, participants fulfilled two questionnaires, which measured subjective vitality and mood state, respectively. Subsequently, participants’ performance was assessed through a Wingate test, which was followed by measurements of RPE at general, muscular, or cardiovascular level. Results: Caffeine supplementation increased some components of mood, as assessed by profile of mood states (POMS) (tension and vigor dimensions) and subjective vitality profiles, which were followed by a greater maximum power, average power, and lower time needed to reach maximum power during the Wingate test. Moreover, lower RPE, both at muscular and general levels were reported by participants after the Wingate test. Conclusions: These results suggest that caffeine supplementation exerts positive effects both in psychological and physical domains in trained subjects.

Abstract P211: Single High Na + Ingestion Leads To An Increase In Oxidative Stress And Triggers Inflammation.

Hypertension ◽  
2021 ◽  
Vol 78 (Suppl_1) ◽  
Author(s):  
Ginette Bordcoch ◽  
Ivan Tavera Busso ◽  
Juan Masjoan Juncos ◽  
Luis I Juncos
Keyword(s):  
Oxidative Stress ◽  
The United States ◽  
Male Rats ◽  
Control Group ◽  
Aortic Tissue ◽  
Tissue Samples ◽  
Extracellular Signal ◽  
High Prevalence ◽  
Markers Of Oxidative Stress ◽  
The Difference

Hypertension has been linked to a progressive increased in oxidative stress and inflammation. The high prevalence of hypertension poses a great risk to public health as 108 million adults in the United States have the condition. For that reason, a better understanding of the link between a high Na+ intake and the development of hypertension is of crucial importance. We hypothesize that a single ingestion of a high Na+ solution leads to increased oxidative stress and triggers an inflammatory response. Wistar 200-250 g male rats had gastric infusions through the esophagus. Groups were infused with 8 mL liquid Vaseline (Control), 8 mL of NaCl 0.684 M (4% m/v), and 8 mL of NaCl 1.368 M (8% m/v). After infusion, blood was collected at different time points during the first hour. Tissue samples were obtained from the aorta, heart, and kidney. Electron Microscopy (EM) was performed on all tissues, which were also analyzed for molecular markers of oxidative stress: Superoxide Dismutase (SOD) and Malondialdehyde (MDA), and an inflammation marker: Extracellular Signal-Regulated Kinase (ERK). At 2 and a half minutes, serum Na+ concentration was unchanged in the control group compared to an increase observed in animals receiving 4% and 8% Na+ with concentrations of 135±1.4 mEq/L, 141±2.0 mEq/L, and 140±1.2 mEq/L respectively. At the 1-hour time point after infusion, the difference was further increased in the 8% group with serum concentrations of 135±1.8 mEq/L, 140±1.5 mEq/L, and 152±1mEq/L respectively (p<0.05). There was an increase in oxidative stress in the aorta from values of 36.22±4.64 mU/mg SOD and 0.131±0.013 pg/mL MDA in the control group, to 47.11±4.89 mU/mg SOD and 0.291±0.022 pg/mL MDA in the 8% group (p<0.05 in both cases). The same was observed in the heart, where values were: 174.6125.26 mU/mg SOD, 0.026±0.007 pg/mL MDA in controls, and 259.22±21.98 mU/mg SOD, 0.215±0.073 pg/mL MDA in 8% group (p<0.05 both cases). Increased ERK in aortic tissue, values of 0.29±0.03 pg/mL in controls, 2.68±0.18 pg/mL in 4% group and 3.97±0.68pg/mL in 8% group (p<0.05) suggest increased inflammation. We conclude that the elevation in serum Na+ concentration that follows Na+ ingestion leads to increased oxidative stress and inflammation.

Organizational Support for Professionalism, Organizational Citizenship Behavior (OCB), and Performance

2021 ◽  
Vol 10 (1) ◽  
pp. 1-12
Author(s):  
Noviana Norrohmat ◽  
Umar Nimran ◽  
Kusdi Raharjo ◽  
Hamidah Nayati Utami ◽  
Endang Siti Astuti
Keyword(s):  
Organizational Citizenship ◽  
Organizational Citizenship Behavior ◽  
Organizational Support ◽  
Citizenship Behavior ◽  
Research Approach ◽  
The Difference ◽  
And Performance ◽  
Relationship Of ◽  
Descriptive Survey ◽  
The Relationship

The purpose of this research is to determine the organizational support for professionalism that has never been done before. The research approach is to conceptualize the structure of the relationship of variables from a study. Verification research is to test the hypothesis through data collection in the field using two methods, namely descriptive survey and explanatory survey. The use of both methods aims to analyze the causality relationship between research variables in accordance with the hypothesis quantitatively. There is significant influence between the variables of organizational support to professional variables. However, different results are found on the influence of organizational support variables on OCB and performance that have no significant effect. There is also an indirect influence between organizational support variables on OCB and performance through intermediary intervening professionalism variables. The difference between this research and the previous research are the use of constructs and the measurement in the unit of analysis being used.

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