Publications by authors named "Kuei Hui Chan"

Chen, C-F, Chuang, C-Y, Wang, C-C, Liu, S-A, Chang, H-W, and Chan, K-H. Lower repetition induces similar postactivation performance enhancement to repetition maximum after a single set of heavy-resistance exercise. J Strength Cond Res 38(5): 848-855, 2024-The study was divided into 2 parts to investigate the acute postactivation performance enhancement (PAPE) responses to lower repetitions at the same load of 87% 1 repetition maximum (1RM) in the upper and lower body.

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Chlorphenesin is a legitimate preservative commonly used in cosmetics. It shares one urinary metabolite of 4-chlorophenoxyacetic acid with meclofenoxate, a prohibited stimulant in sports. Recently, there have been cases where athletes using chlorphenesin-containing products were falsely identified as users of meclofenoxate.

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The purpose of this study was to investigate the effects of 6-week betaine supplementation during a preparatory period of collegiate athletes on muscular power and strength. Sixteen male collegiate athletes received 5 g/day of betaine (betaine group, n = 9) or carboxymethyl cellulose (placebo group, n = 7) for 6 weeks. All participants engaged in their regular training during the experimental period.

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This study evaluated the effects of 2 weeks of betaine supplementation on apoptosis, oxidative stress, and aerobic capacity after exhaustive endurance exercise (EEE). A double-blind, crossover, and counterbalanced design was adopted, with 10 healthy male participants asked to consume betaine (1.25 g of betaine mixed with 300 mL of sports beverage, twice per day for 2 weeks) or placebo (300 mL of sports beverage).

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Background: Chronic exercise training has been shown be to positively associated with executive function (EF) in older adults. However, whether the exercise training effect on EF is affected by moderators including the specific sub-domain of EF, exercise prescription variables, and sample characteristics remains unknown.

Objectives: This systematic and meta-analytic review of randomized controlled trials (RCTs) investigated the effects of exercise training on EF in older adults and explored potential moderators underlying the effects of exercise training on EF.

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Creatine supplementation has an ergogenic effect in an acute complex training bout, but the benefits of chronic creatine supplementation during long-term complex training remain unknown. The study aimed to evaluate the effects of 4-week complex training combined with creatine supplementation on sport performances and muscle damage biomarkers. Thirty explosive athletes were assigned to the creatine or placebo group, which consumed 20 g of creatine or carboxymethyl cellulose, respectively, per day for 6 days followed by 2 g of the supplements until the end of the study.

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Creatine supplementation reduces the impact of muscle fatigue on post-activation potentiation (PAP) of the lower body, but its effects on the upper body remain unknown. This study examined the effects of creatine supplementation on muscle strength, explosive power, and optimal individual PAP time of the upper body during a set of complex training bouts in canoeists. Seventeen male high school canoeists performed a bench row for one repetition at maximum strength and conducted complex training bouts to determine the optimal individual timing of PAP and distance of overhead medicine ball throw before and after the supplementation.

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The purpose of this study was to compare the effects of high-intensity interval training (HIIT) and moderate-intensity continuous training (MICT) utilizing a canoeing ergometer on endurance determinants, as well as aerobic and anaerobic performances among flat-water canoeists. Fourteen well-trained male flat-water canoeists were divided into an HIIT group or an MICT group. All subjects performed a continuous graded exercise test (GXT) and three fixed-distance (200, 500, and 1000 m) performance tests on a canoeing ergometer to determine canoeing economy, peak oxygen uptake (VOpeak), and power at VOpeak, and to calculate the critical velocity (CV) and anaerobic work capacity before and after the training programmes.

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Introduction: A recent US Major League Baseball (MLB) rule change requires baseball pitchers to deliver pitches within 12 s.

Purposes: To examine the effect of three between-pitch rest intervals on throwing performance during a simulated seven-inning game and muscle damage during postgame recovery.

Design: A randomized counterbalanced study.

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Creatine plays an important role in muscle energy metabolism. Postactivation potentiation (PAP) is a phenomenon that can acutely increase muscle power, but it is an individualized process that is influenced by muscle fatigue. This study examined the effects of creatine supplementation on explosive performance and the optimal individual PAP time during a set of complex training bouts.

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This study was designed to examine the modulation of executive functions during acute exercise and to determine whether exercise intensity moderates this relationship. Eighty college-aged adults were recruited and randomly assigned into one of the four following groups: control, 30%, 50%, and 80% heart rate reserve. The Wisconsin Card Sorting Test (WCST) was administered during each intervention.

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This study investigated the effects of BCAA, arginine and carbohydrate combined beverage (BCAA Drink) on biochemical responses and psychological conditions during recovery after a single bout of exhaustive exercise. Fourteen healthy males were assigned to drink either BCAA Drink (BA trial) or placebo (PL trial) on two sessions separated by 2 weeks. Blood samples of each subject were collected before exercise, 0, 10, 20, 40, 60, 120 min and 24 h after exercise.

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The purpose of this study was to investigate the effects of a proprietary blend of soybean peptides, taurine, Pueraria isoflavone, and ginseng saponin complex (STPG capsule) on exercise performance in humans. Fourteen male volunteers were randomly assigned to two crossover treatments in which they consumed either four STPG capsules (STPG treatment) or placebo (P treatment) for 15 days before a 75% maximal oxygen uptake (VO(2max)) exhaustive cycling test. Blood samples and respiratory gas were collected prior to the exercise (Pre-Ex), at 10 (Ex-10), 15 (Ex-15), 20 (Ex-20), and 25 (Ex-25) minutes during exercise, and immediately after exercise (exhaustion) to assess the blood metabolites, cardiorespiratory responses, and energy substrate utilization.

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Famprofazone, a major ingredient of Gewolen, is an analgesic that has been demonstrated to be metabolized to methamphetamine (MA) and amphetamine (AM) following administration. Therefore, a famprofazone user may be interpreted as an illicit MA abuser in Taiwan because the user's urine tested positive for MA. The purpose of this study was to investigate whether the concentration of MA metabolized from a single dose of Gewolen users would offend the official controlled substance regulation and be identified as MA-positive.

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Sho-seiryu-to is one of the most common Traditional Chinese Medicine preparations for the attenuation of colds. Ephedrae Herba is one of the prescriptions of Sho-seiryu-to. The major ingredients of Ephedrae Herba, ephedrines, are banned substances on the World Anti-Doping Agency (WADA) list.

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The urine specimens of numerous athletes were found to be positive for mephentermine both in-competition and out-of-competition in Taiwan. The donor of one specimen claimed she had only taken Mucaine (contains oxethazaine) for relieving symptomatic peptic ulcer and gastritis. Oxethazaine is not included in the prohibited list of the World Anti-Doping Agency; however, its metabolized compounds, mephentermine and phentermine, are included in that list.

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Kakkon-to is one of the most common Traditional Chinese Medicine preparations for the attenuation of colds. Ephedrae Herba is one of the prescriptions of Kakkon-to. The major ingredients of Ephedrae Herba, ephedrines, are banned substances on the World Anti-Doping Agency (WADA) list.

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The aim of this study was to examine changes in muscle cell injury and antioxidant capacity of weightlifters following a 1-week intensive resistance-training regimen. Thirty-six female subjects participated in this study, and their ages ranged from 18 to 25 years. The sample group included 19 elite weightlifters with more than 3 years of weightlifting training experience, while the control group comprised 17 non-athletic individuals.

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A rapid and reliable high-performance liquid chromatographic method was developed and validated for the simultaneous determination of norephedrine (NE), norpseudoephedrine (NPE), ephedrine (E), pseudoephedrine (PE), methylephedrine (ME) and methylpseudoephedrine (MPE) in both a Mahwang traditional Chinese medicine (TCM) preparation and in urine using alpha-ethylbenzylamine as the internal standard. The method uses a Spherisorb C(18) column for an isocratic elution in a tetraethylammoniumphosphate-methanol mobile phase at a wavelength of 206 nm. The limits of detection of NE, NPE, E, PE, ME and MPE in sample solutions ranged from 0.

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