scholarly journals Effects of two different doses of carbohydrate ingestion on taekwondo-related performance during a simulated tournament

Author(s):  
Alireza Naderi ◽  
Mohammad Hossein Samanipour ◽  
Amir Sarshin ◽  
Scott C. Forbes ◽  
Majid S. Koozehchian ◽  
...  

Abstract Background Carbohydrate (CHO) ingestion enhances exercise performance; however, the efficacy of CHO intake on repeated bouts of exercise simulating a taekwondo tournament is unknown. Therefore, the purpose was to compare the effects of two different doses of CHO on a sports-specific kicking test during a simulated taekwondo tournament compared to placebo (PLA). Methods In a double-blind, randomized-placebo controlled, cross-over trial, eleven junior male professional taekwondo athletes (age: 16 ± 0.8 years, body mass: 55.3 ± 7.3 kg) ingested one of three solutions: (i) high dose (C45): 45 g of CHO (60 g∙h− 1), (ii) low dose (C22.5): 22.5 g of CHO (30 g∙h− 1; both solutions containing 2:1 glucose:fructose), or a PLA immediately following each kicking test. The kicking test was repeated 5 times, separated by 45 mins of rest, simulating a typical taekwondo competition day. Ratings of perceived exertion (RPE) and gastrointestinal discomfort (GI) scores were collected immediately after, and blood glucose before each test. Results The results revealed that C45 and C22.5 did not improve total, successful, or percentage of successful kicks compared to PLA (p > 0.05). Blood glucose was significantly higher following both CHO conditions compared with PLA across all five tests (p < 0.05). There were no differences between treatments or across tests for RPE (p > 0.05). Conclusion CHO intake, independent of the dose, did not alter taekwondo kick performance during a simulated taekwondo tournament.

1992 ◽  
Vol 2 (4) ◽  
pp. 317-327 ◽  
Author(s):  
Randall L. Wilber ◽  
Robert J. Moffatt

Ten trained male runners performed a treadmill exercise test at 80%under two experimental conditions, carbohydrate (CHO, 7% carbohydrate) and placebo (P), to determine the effect of carbohydrate ingestion on endurance performance (treadmill run time), blood glucose concentration, respiratory exchange ratio (RER), and subjective ratings of perceived exertion (RPE). Treatment order was randomized and counterbalanced and test solutions were administered double-blind. Ingestion took place 5 min preexercise (250 ml) and at 15-min intervals during exercise (125 ml). Performance was enhanced by 29.4% (p~ 0.05) during CHO (115 ±25 min) compared to P (92 ± 27 min). Blood glucose concentration was significantly greater during CHO (5.6 ± 0.9 mM) relative to P (5.0 ±0.7 mM). There was a significant increase in mean RER following CHO ingestion (.94±.01) compared to P (.90±.01). Average RPE was significantly less during CHO (14.5±2.3) relative to P (15.4±2.4). These data suggest that time to exhaustion of high-intensity treadmill exercise is delayed as a result of carbohydrate ingestion and that this effect is mediated by favorable alterations in blood glucose concentration and substrate utilization.


2021 ◽  
Vol 2021 ◽  
pp. 1-6
Author(s):  
Tatyanne Letícia N. Gomes ◽  
Renata Santos S. Zenha ◽  
Alisson H. Antunes ◽  
Flávia R. Faria ◽  
Kênnia R. Rezende ◽  
...  

Curcumin is a bioactive compound derived from Curcuma longa L. root, extensively studied due to its antioxidant and anti-inflammatory properties. This study evaluates the effects of different doses of powdered C. longa root on antioxidant capacity in healthy men. In a pilot randomized, double-blinded, crossover experiment, we acutely administered a low dose (1.5 g, LCG), moderate dose (3.0 g, MCG), and high dose (6.0 g, HCG) of C. longa to nine healthy men. There were no differences in plasma curcumin levels ( p = 0.593 ) and antioxidant capacity ( p = 0.473 ) for time × group interactions. Plasma curcumin levels increased in all groups after 20 and 90 min of C. longa intake ( p < 0.05 ). HCG had a lower postprandial incremental area under the antioxidant capacity curve than LCG or MCG ( p < 0.01 ). A low dose of C. longa increased the antioxidant capacity in healthy men. However, plasma curcumin levels were not dose dependently affected.


2021 ◽  
Vol 7 (4) ◽  
pp. 697-705
Author(s):  
Jianhui Ma ◽  
Meimei Pang ◽  
Xin Ding ◽  
Shirong Fang ◽  
Lichao Chu

Objective. To explore the effect of different doses of propofol and nerve block combined with general anesthesia on the intraoperative anesthesia and postoperative awakening and cognitive function in elder patients with knee osteoarthritis (OA). Methods. According to the inclusion criteria for research object, we selected 98 elderly patients with knee OA who needed surgery and were admitted to our hospital from January 2019 to January 2021 for the study. Patients were divided into the low dose group (given 2 mg/kg propofol by pumping under constant speed during surgery) and the high dose group (given 4 mg/kg propofol by pumping during surgery) by the number table method to compare their indicators including the intraoperative anesthesia effect, with 49 cases in each group. Results. No between-group difference was shown in the anesthesia time and postoperative VAS scores, but the awakening time of the low dose group was significantly shorter than that of the high dose group (P<0.05); the differences in heart rate (HR) values at various time points between the two groups were not obvious, but the high dose group obtained significantly higher HR values at T4 than the low dose group; the mean arterial pressure (MAP) values of both groups were significantly reduced at Ti and then returned to the level before anesthesia (P>0.05); the bispectral index scores (BIS) of both groups experienced a marked drop at Ti and then recovered gradually, but failed to return to the level at T0 till the end, and a between-group difference in BIS indexes presented at Ti; the plasma corticosterone (CORT) concentration at Ti of both groups were significantly lowered and then returned to the level at T0, with no between-group difference; and compared with the low dose group, the high dose group achieved slightly lower mini-mental state examination (MMSE) scores at 24-72 h after surgery, with no significant difference between them (P>0.05). Conclusion. The therapy of different doses of propofol and nerve block combined with general anesthesia has no significant effect on the cognitive function in elderly knee OA patients after surgery. With the nerve block improving the analgesic effect, a low dose of propofol is good for the postoperative awakening of patients. Different doses of propofol inhibited the stress response to a different degree and produced good anesthesia outcomes in elderly patients, but comparatively speaking, a low-dose propofol ensures more smooth indexes and less effect on the intraoperative hemodynamics.


1981 ◽  
Vol 26 (6) ◽  
pp. 395-401 ◽  
Author(s):  
D. Garfinkel Barry ◽  
D. Webster Christopher ◽  
Leon Sloman

Six children with the diagnosis of Attention Deficit Disorder were treated as day hospital patients, using different stimulant medication. They were studied in a double-blind crossover experiment in which they received caffeine in low dose or in a high dose. Methylphenidate was added to both dosages, as well as administered alone. Results indicated that caffeine in low dosage when added to methylphenidate was superior to all other treatment conditions. Caffeine in low dosage could not be differentiated from 10 mg of methylphenidate. High dosage caffeine was not different from placebo or no-drug conditions. This study offers evidence to support a curvilinear pattern of dose-response for caffeine, in attenuating the behavioural manifestations of this syndrome.


Hypertension ◽  
2020 ◽  
Vol 76 (3) ◽  
pp. 724-731
Author(s):  
Lucy Norcliffe-Kaufmann ◽  
Jose-Alberto Palma ◽  
Jose Martinez ◽  
Horacio Kaufmann

Afferent lesions of the arterial baroreflex occur in familial dysautonomia. This leads to excessive blood pressure variability with falls and frequent surges that damage the organs. These hypertensive surges are the result of excess peripheral catecholamine release and have no adequate treatment. Carbidopa is a selective DOPA-decarboxylase inhibitor that suppresses catecholamines production outside the brain. To learn whether carbidopa can inhibit catecholamine-induced hypertensive surges in patients with severe afferent baroreflex failure, we conducted a double-blind randomized crossover trial in which patients with familial dysautonomia received high dose carbidopa (600 mg/day), low-dose carbidopa (300 mg/day), or matching placebo in 3 4-week treatment periods. Among the 22 patients enrolled (13 females/8 males), the median age was 26 (range, 12–59 years). At enrollment, patients had hypertensive peaks to 164/116 (range, 144/92 to 213/150 mm Hg). Twenty-four hour urinary norepinephrine excretion, a marker of peripheral catecholamine release, was significantly suppressed on both high dose and low dose carbidopa, compared with placebo ( P =0.0075). The 2 co-primary end points of the trial were met. The SD of systolic BP variability was reduced at both carbidopa doses (low dose: 17±4; high dose: 18±5 mm Hg) compared with placebo (23±7 mm Hg; P =0.0013), and there was a significant reduction in the systolic BP peaks on active treatment ( P =0.0015). High- and low-dose carbidopa were similarly effective and well tolerated. This study provides class Ib evidence that carbidopa can reduce blood pressure variability in patients with congenital afferent baroreflex failure. Similar beneficial effects are observed in patients with acquired baroreflex lesions.


2019 ◽  
Vol 126 (3) ◽  
pp. 515-529
Author(s):  
Marina Saldanha da Silva Athayde ◽  
Rafael L. Kons ◽  
Daniele Detanico

This study analyzed the effects of caffeine ingestion during judo matches on judo athletes' match-derived performance and perceived exertion responses. We applied a double-blind randomized crossover (caffeine vs. placebo conditions) research design. Twelve male athletes performed three 5-minute matches separated by 15 minutes of passive rest. Immediately after each match, the athletes completed ratings of perceived exertion (RPEs), and one minute before beginning the second and third matches, they provided ratings of perceived recovery (RPRs). We filmed all matches for subsequent analysis of the athletes' technical skills. We found no interaction between condition and time of RPE, RPR, and match-derived technical variables, but number of attacks and RPR decreased over the matches, and RPE increased in both conditions. Three participants showed individual positive responses to caffeine ingestion for number of attacks. Attacks, efficiency, and effectiveness presented low sensitivity in both conditions, as only large changes could be identified. We conclude that caffeine ingestion did not provoke changes in either perceived exertion or match-derived performance. Match-derived technical variables were not sensitive for detecting small or medium effects of caffeine, but perceived exertion may detect at least medium effect after caffeine ingestion.


2019 ◽  
Vol 2019 ◽  
pp. 1-12 ◽  
Author(s):  
Sanjib Kumar Sharma ◽  
Emilie Alirol ◽  
Anup Ghimire ◽  
Suman Shrestha ◽  
Rupesh Jha ◽  
...  

Diagnosing and treating acute severe and recurrent antivenom-related anaphylaxis (ARA) is challenging and reported experience is limited. Herein, we describe our experience of severe ARA in patients with neurotoxic snakebite envenoming in Nepal. Patients were enrolled in a randomised, double-blind trial of high vs. low dose antivenom, given by intravenous (IV) push, followed by infusion. Training in ARA management emphasised stopping antivenom and giving intramuscular (IM) adrenaline, IV hydrocortisone, and IV chlorphenamine at the first sign/s of ARA. Later, IV adrenaline infusion (IVAI) was introduced for patients with antecedent ARA requiring additional antivenom infusions. Preantivenom subcutaneous adrenaline (SCAd) was introduced in the second study year (2012). Of 155 envenomed patients who received ≥ 1 antivenom dose, 13 (8.4%), three children (aged 5−11 years) and 10 adults (18−52 years), developed clinical features consistent with severe ARA, including six with overlapping signs of severe envenoming. Four and nine patients received low and high dose antivenom, respectively, and six had received SCAd. Principal signs of severe ARA were dyspnoea alone (n=5 patients), dyspnoea with wheezing (n=3), hypotension (n=3), shock (n=3), restlessness (n=3), respiratory/cardiorespiratory arrest (n=7), and early (n=1) and late laryngeal oedema (n=1); rash was associated with severe ARA in 10 patients. Four patients were given IVAI. Of the 8 (5.1%) deaths, three occurred in transit to hospital. Severe ARA was common and recurrent and had overlapping signs with severe neurotoxic envenoming. Optimising the management of ARA at different healthy system levels needs more research. This trial is registered withNCT01284855.


2020 ◽  
Vol 46 (Supplement_1) ◽  
pp. S216-S217
Author(s):  
Chao Ma ◽  
Yan Wu ◽  
Pei Chen ◽  
Yuan Jia ◽  
Dongqing Yin ◽  
...  

Abstract Background Our previous study indicated a therapeutic effect of Shi-Zhen-An-Shen-Tang (SZAST), a Chinese herb formula, on schizophrenia, but the related mechanism is unknown(citation). A large body of evidence suggests the important role of white matter of the brain in the pathophysiology of schizophrenia. This study was designed to evaluate the effect of SZAST on schizophrenia with demyelinated mice. Methods Male C57BL/6 mice were given mixed cuprizone (CPZ, a copper chelator, 0.2 %, w/w) rodent chow for six successive weeks to induce demyelination. During the last two weeks, mice were given an oral gavage of saline, or SZAST of three different doses (a low dose of 5.5g·kg-1·d-1, a medium dose of 8.24g·kg-1·d-1, or a high dose of 10.98 g·kg-1·d-1), or quetiapine, respectively. Behavioral tests were conducted after the last treatment. Meanwhile, the expression of myelin basic protein (MBP) and neuregulin-1(NRG1) in the brain was tested by immunohistochemistry staining or Western Blot. Results Mice exposed to CPZ for six weeks showed obvious schizophrenia-like behaviors, including lower nest-building activity, sensory gating activity, and higher locomotor activity. CPZ-fed mice also displayed a lower myelin density in the corpus callosum, hippocampus, and cerebral cortex and a reduction of MBP and NRG1 protein in the hippocampus compared with controls. Both quetiapine and SZAST significantly alleviated the abnormal schizophrenia-like behaviors and the impairment of myelin sheath in CPZ-fed mice, however, SZAST with medium dose showed better neuroprotective effect than the low dose or the high dose of SZAST. Furthermore, the expression of NRG1protein in the hippocampus was slightly, but not significantly increased in all SZAST-treated and quetiapine-treated groups. Discussion These results indicate that the neuroprotective effect of SZAST in demyelinated mice might partially relate to remyelination in the hippocampus in CPZ-fed mice.


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