ABSTRACT: 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 XX(X): 000-000, 2023-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. In part 1, 14 athletes performed plyometric push-up (PPU) after the conditioning activity (CA) of bench press (BP). In part 2, 13 athletes performed a countermovement jump (CMJ) after the CA of parallel squat (PS). Subjects completed 3, 4, or 5 repetitions (trials CA-3, CA-4, or CA-5) of BP or PS in randomized and counterbalanced order. The velocity of each movement of the trial was recorded. The PPU or CMJ was tested every 2 minutes after the trial up to 12 minutes to assess the Post-Max and optimal individual PAPE time. The mean velocity of the last movement of BP in CA-5 was significantly lower than that in CA-3 (0.23 ± 0.06 vs. 0.28 ± 0.06 m·second -1 , p < 0.05), and the velocity of PS in CA-4 or CA-5 was significantly lower than that in CA-3 (0.53 ± 0.07 and 0.50 ± 0.05 vs. 0.57 ± 0.07 m·second -1 , p < 0.05). The peak force of PPU and jump height of CMJ at Post-Max in the 3 trials were significantly greater than those at Pre ( p < 0.05). There were no significant differences among trials in the optimal individual PAPE times in either part of the study. A single set of 87% 1RM resistance exercises with 3 or 4 repetitions in both the upper body and the lower body induces similar PAPE to repetition maximum.
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. This study developed and validated a liquid chromatography method with diode-array detection to determine the chlorphenesin content in 61 selected personal care products with various functions (e.g., facial care, body cleansing, sun protection, make-up, hairstyling, perfume, and oral cleaning). The analytical method demonstrated fit-for-purpose quantitation and provided good linearity, precision, accuracy, and recovery for analyzing different cosmetic matrices. Among the 27 cosmetics labeled with chlorphenesin, the chlorphenesin concentrations ranged from 0.10 to 2.67 mg/g, with three products showing no detection. None of the products exceeded the maximum limit of 3 mg/g (0.3%) set by regulatory authorities. Among the 34 cosmetics not labeled with chlorphenesin, none of them contained chlorphenesin. This study confirmed the absence of undeclared chlorphenesin in the selected cosmetics, supporting the correctness of chlorphenesin labeling in cosmetics sold in Taiwan. Further investigations studying urinary excretion patterns after different types, doses, frequencies, and sites of cosmetics applications could contribute to strengthen current testing approaches in anti-doping.
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. The overhead medicine-ball throw (OMBT), countermovement jump, and maximal strength (one repetition maximum, 1-RM) on the bench press, overhead press, half squat, and sumo dead lift by the participants were assessed before and after betaine supplementation. Blood lipids were also analyzed before and after betaine supplementation. After supplementation, there were no significant differences between betaine and placebo groups on any variables. Compared to presupplementation, the performance of OMBT and 1-RM of overhead press and half squat in the betaine group had significantly improved (p < 0.05). By contrast, no significant differences were observed in the placebo group before and after supplementation. Blood analysis revealed no negative effect on blood lipid profiles. Betaine seems to be a useful nutritional strategy to improve and maintain performance during 6-week preparatory periods in collegiate athletes.
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). All participants performed a graded exercise test on a treadmill to determine the maximal oxygen consumption (VO2max) before supplementation and then performed the EEE test at an intensity of 80% VO2max after 2 weeks of supplementation. The time to exhaustion, peak oxygen consumption, maximal heart rate, and average heart rate were recorded during the EEE test. Venous blood samples were drawn before, immediately after, and 3 h after the EEE test to assess apoptosis and the mitochondrial transmembrane potential (MTP) decline of lymphocytes as well as the concentrations of thiobarbituric acid reactive substance and protein carbonyl. The results indicated that lymphocyte apoptosis was significantly higher immediately after and 3 h after EEE than before exercise in participants in the placebo trial. However, lymphocyte apoptosis exhibited no significant differences among the three time points in participants in the betaine trial. Moreover, apoptosis in the betaine trial was significantly lower immediately after and 3 h after exercise compared with the placebo trial. No differences were noted for other variables. Thus, 2 weeks of betaine supplementation can effectively attenuate lymphocyte apoptosis, which is elevated by EEE. However, betaine supplementation exhibited no effects on MTP decline, oxidative stress, or aerobic capacity.
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. METHODS: In accordance with the PRISMA guidelines, the electronic databases MEDLINE (PubMed) and EMBASE (Scopus) were searched from January 2003 to November 2019. All studies identified for inclusion were peer-reviewed and published in English. To be included, studies had to report findings from older (> 55 years old), cognitively normal adults or adults with mild cognitive impairment (MCI) randomized to an exercise training or a control group. The risk of bias in each study was appraised using the Cochrane risk-of-bias tool. Fixed-effects models were used to compare the effects of exercise training and control conditions on EF assessed at baseline and post-intervention. In addition, subgroup analyses were performed for three moderators (i.e., the specific sub-domain of EF, exercise prescription variables, and sample characteristics). RESULTS: Thirty-three RCTs were included. Overall, exercise training was associated with a significant small improvement in EF [Q(106) = 260.09, Hedges' g = 0.21; p < 0.01]. The EF sub-domain moderator was not significant [Q(2) = 4.33, p > 0.05], showing that the EF improvement in response to exercise is evident for measures of inhibition, updating, and shifting. Regarding exercise prescription variables, results were significantly moderated by frequency of exercise training [Q(1) = 10.86, p < 0.05], revealing that effect sizes (ESs) were larger for moderate frequency (g = 0.31) as compared to low frequency exercise (g = 0.15). The results also showed type of exercise training moderated the ESs [Q(4) = 26.18, p < 0.05], revealing that ESs were largest for other forms of exercise (g = 0.44), followed by Tai Chi and yoga (g = 0.38), resistance exercise (g = 0.22), aerobic exercise (g = 0.14), and combined exercise (g = 0.10). In addition, The results showed moderated length of training the ESs [Q(2) = 16.64, p < 0.05], revealing that ESs were largest for short length (g = 0.32), followed by mid length (g = 0.26) and long length (g = 0.09). No significant difference in effects was observed as a function of exercise intensity [Q(1) = 2.87 p > 0.05] and session time [Q(2) = 0.21, p > 0.05]. Regarding sample characteristics, the results were significantly moderated by age [Q(2) = 20.64, p < 0.05], with significant benefits for young-old (55-65 years old) (g = 0.30) and mid-old (66-75 years old) (g = 0.25), but no effect on EF for old-old (more than 75 years old). The results were also significantly moderated by physical fitness levels [Q(1) = 10.80, p < 0.05], revealing that ESs were larger for sedentary participants (g = 0.33) as compared to physically fit participants (g = 0.16). In addition, results were also significantly moderated by cognitive status [Q(1) = 11.44, p < 0.05], revealing that ESs were larger for participants with cognitively normal (g = 0.26) as compared to those with mild cognitive impairment (g = 0.08). No significant differences in effects were observed as a function of sex [Q(2) = 5.38, p > 0.05]. CONCLUSIONS: Exercise training showed a small beneficial effect on EF in older adults and the magnitude of the effect was different across some moderators.
Cognition , Cognitive Dysfunction/therapy , Executive Function , Exercise Therapy , Aged , Humans , Middle Aged , Randomized Controlled Trials as Topic
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. After 6 days of supplementation, subjects performed tests of one repetition maximum (1-RM) strength of half squat and complex training bouts to determine the optimal individual post-activation potentiation time. Thereafter, all subjects performed a complex training programme consisting of six sets of 5-RM half squats and plyometric jumps 3 times per week for 4 weeks. Body composition, 30-m sprint and jump performances were assessed before and after the training period. Moreover, blood creatine kinase (CK) activity was analysed at the first and the last training bout. After the training, the 1-RM strength in the creatine group was significantly greater than in the placebo group (p < 0.05). CK activity after the complex training bout in the creatine group was significantly reduced compared with the placebo group (p < 0.05). No differences were noted for other variables. This study concluded that creatine supplementation combined with complex training improved maximal muscular strength and reduced muscle damage during training.
Athletes , Creatine/pharmacology , Muscle, Skeletal/drug effects , Muscle, Skeletal/injuries , Sports , Adolescent , Body Composition , Creatine/administration & dosage , Dietary Supplements , Double-Blind Method , Drug Administration Schedule , Exercise , Humans , Male , Performance-Enhancing Substances/metabolism , Resistance Training , Young Adult
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. Subjects were assigned to a creatine or placebo group, and later consumed 20 g of creatine or carboxymethyl cellulose per day for six days. After supplementation, the maximal strength in the creatine group significantly increased (p < 0.05). The optimal individual PAP time in the creatine group was significantly earlier than the pre-supplementation times (p < 0.05). There was no significant change in explosive power for either group. Our findings support the notion that creatine supplementation increases maximal strength and shortens the optimal individual PAP time of the upper body in high school athletes, but has no effect on explosive power. Moreover, it was found that the recovery time between a bench row and an overhead medicine ball throw in a complex training bout is an individual phenomenon.
Creatine/pharmacology , Dietary Supplements , Muscle Fatigue , Muscle Strength/drug effects , Muscle, Skeletal/drug effects , Physical Exertion/drug effects , Water Sports/physiology , Adolescent , Athletes , Double-Blind Method , Humans , Male , Movement , Muscle, Skeletal/physiology , Physical Exertion/physiology , Ships
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 1000â m) performance tests on a canoeing ergometer to determine canoeing economy, peak oxygen uptake (VO2peak), and power at VO2peak, and to calculate the critical velocity (CV) and anaerobic work capacity before and after the training programmes. The training programme involved training on a canoeing ergometer three times per week for four weeks. HIIT consisted of seven 2 min canoeing bouts at an intensity of 90% VO2peak separated by 1 min of rest. The MICT group was trained at an intensity of 65% VO2peak continuously for 20 min. After four weeks of training, performance in the 200-m distance test and the power at VO2peak significantly improved in the HIIT group; performance in the 500â m and 1000â m distances and CV significantly improved in the MICT group. However, all variables were not significantly different between groups. It is concluded that HIIT for four weeks is an effective training strategy for improvement of short-distance canoeing performance. In contrast, MICT improves middle-distance canoeing performances and aerobic capacity.
Athletic Performance , High-Intensity Interval Training , Water Sports/physiology , Adolescent , Exercise Test , Humans , Male , Young Adult
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. METHODS: Seven intercollegiate pitchers threw 15 pitches per inning for seven innings with rest interval trials of 8, 12, and 20 s between pitches and 5 min between innings. Pitchers threw aimed fastballs at their best effort. Trials were separated by ≥2 wk. RESULTS: Progressive decreases in pitching speed and accuracy below baseline (first inning of 20-s trial) occurred after fourth inning during the 8-s and 12-s trials, but not the 20-s trial. Plasma creatine kinase elevated 48 h later for the 8-s and 12-s trials (+105% and +75%, P < 0.01), but not the 20-s trial (+26%, no significance). A transient interleukin (IL)-6 surges immediately after the game for the 8- and 12-s trials (+265%, +128%, P < 0.01) above baseline. IL-6 reversed below the level of 20-s trial at 48 h after game, whereas IL-10 increased significantly above the level of 20-s trial. CONCLUSIONS: Under the same pitching load, decreasing rest interval from 20 to 12 s or less results in an early-onset performance loss during a game and increases in muscle damage and inflammation for more than 2 d after a game. Our data do not favor the current rule change in concern of keeping musculoskeletal health of pitchers.
Athletic Performance/physiology , Baseball/injuries , Baseball/physiology , Muscle, Skeletal/injuries , Muscle, Skeletal/physiopathology , Creatine Kinase/blood , Humans , Interleukin-10/blood , Interleukin-6/blood , Male , Muscle Fatigue/physiology , Myalgia/etiology , Myositis/blood , Myositis/etiology , Time Factors , Young Adult
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. Thirty explosive athletes performed tests of back squat for one repetition maximum (1RM) strength and complex training bouts for determining the individual optimal timing of PAP, height and peak power of a counter movement jump before and after the supplementation. Subjects were assigned to a creatine or placebo group and then consumed 20 g of creatine or carboxymethyl cellulose per day for six days. After the supplementation, the 1RM strength in the creatine group significantly increased (p < 0.05). The optimal individual PAP time in the creatine group was also significant earlier than the pre-supplementation and post-supplementation of the placebo group (p < 0.05). There was no significant difference in jump performance between the groups. This study demonstrates that creatine supplementation improves maximal muscle strength and the optimal individual PAP time of complex training but has no effect on explosive performance.
Creatinine/administration & dosage , Dietary Supplements , Energy Metabolism/drug effects , Exercise Tolerance/drug effects , Muscle Contraction/drug effects , Muscle, Skeletal/drug effects , Performance-Enhancing Substances/administration & dosage , Creatinine/metabolism , Double-Blind Method , Humans , Male , Muscle Fatigue/drug effects , Muscle Strength/drug effects , Muscle, Skeletal/metabolism , Performance-Enhancing Substances/metabolism , Time Factors , Treatment Outcome , Young Adult
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. The results indicated that the majority of the WCST performances were impaired in the high exercise intensity group relative to those of the other three groups, whereas similar performance rates were maintained in the low- and moderate-intensity groups. These findings suggest that transient hypofrontality occurs during high-intensity exercise, but not during low- and moderate-intensity exercises. Future research aimed at employing the dual-mode theory, and applying the reticular-activating hypofrontality model is recommended to further the current knowledge.
Executive Function , Exercise/psychology , Adult , Exercise/physiology , Female , Humans , Male , Neuropsychological Tests , Young Adult
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. No significant differences in the levels of lactate, ammonia, creatine kinase and glycerol between the two groups were observed at any of the time points. However, the levels of glucose and insulin were significantly higher in the BA trial as compared to those in the PL trial at the 40 and 60 min recovery points. Furthermore, the testosterone-to-cortisol ratio at the 120 min recovery point was significantly higher in the BA trial as compared to that in the PL trial. The results indicate the occurrence of anabolic response during the recovery period. The benefit of BCAA Drink was also performed by Profile of Mood States to assess the psychological condition. Fatigue score increased immediately at exhaustion in both groups, but the decrease in the fatigue score at 120 min recovery point was significant only in BA trial. These data indicate that a single bout of exhaustive exercise enhanced the feeling of fatigue. The detrimental consequence was reduced by an ingestion of BCAA Drink.
Amino Acids, Branched-Chain/administration & dosage , Arginine/administration & dosage , Beverages , Exercise/psychology , Physical Endurance/drug effects , Physical Endurance/physiology , Affect/drug effects , Affect/physiology , Cross-Over Studies , Dietary Carbohydrates/administration & dosage , Exercise/physiology , Fatigue/drug therapy , Fatigue/physiopathology , Hormones/blood , Humans , Lactic Acid/blood , Male , Tryptophan/blood , Young Adult
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. The result showed that exercise time to exhaustion of the 75% (VO(2max)) exhaustive cycling test of the STPG-treated subjects was significantly greater than with the P treatment (30.99 ± 2.01 vs. 28.05 ± 1.48 minutes). The plasma lactate concentrations at Ex-20 and Ex-25 in the STPG treatment were significantly lower with STPG treatment than with P treatment (10.5 ± 0.7 vs. 11.5 ± 0.8 and 10.7 ± 0.9 vs.12.3 ± 1.0 mmol/L, respectively). Nonesterified fatty acid levels at Ex-15, Ex-20, Ex-25, and exhaustion in the STPG group (0.27 ± 0.03, 0.32 ± 0.04, 0.32 ± 0.06, and 0.37 ± 0.05 mmol/L, respectively) were significantly higher than those in the P treatment (0.21 ± 0.03, 0.23 ± 0.03, 0.24 ± 0.03, and 0.25 ± 0.03 mmol/L, respectively). It was concluded that supplementation of four capsules (2 g) of STPG complex, consisting of soybean peptides, taurine, Pueraria isoflavone, and ginseng saponin, for 15 days was effective in promoting utilization of free fatty acids and improving exhaustive cycling test performance in humans.
Exercise/physiology , Isoflavones/pharmacology , Physical Endurance/drug effects , Plant Extracts/pharmacology , Saponins/pharmacology , Soybean Proteins/pharmacology , Taurine/pharmacology , Adult , Bicycling/physiology , Cross-Over Studies , Dietary Supplements , Fatty Acids, Nonesterified/blood , Humans , Lactic Acid/blood , Male , Oxygen Consumption/drug effects , Panax/chemistry , Physical Endurance/physiology , Pueraria/chemistry , Glycine max/chemistry , Young Adult
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. Subjects (n = 6) received 25 mg of famprofazone and collected all urine specimens at certain timed intervals for 48 h after drug administration. The urine specimens were screened by immunoassay and then confirmed by gas chromatography-mass spectrometry (GC-MS). The highest concentration of amphetamines by immunoassay was 1954 ng/mL, and 18.8% of the urine specimens' amphetamines concentrations exceeded 500 ng/mL. The MA and AM concentrations by GC-MS analysis of these urine specimens ranged from 901 to 2670 ng/mL and 208 to 711 ng/mL, respectively. These urine specimens were interpreted as MA-positive (>or= 500 ng/mL MA and >or= 100 ng/mL AM), according to the official test methods of Taiwan. The MA positive results appeared within 2-34 h. It is therefore clearly possible to misinterpret the legitimate famprofazone user as an MA abuser in Taiwan.
Analgesics/urine , Diagnostic Errors , Methamphetamine/analogs & derivatives , Methamphetamine/urine , Pyrazolones/urine , Substance Abuse Detection , Adult , False Positive Reactions , Female , Humans , Male , Young Adult
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. The purpose of this study was to investigate the elimination of urinary ephedrines after administering Sho-seiryu-to preparation and to determine the possibility of positive ephedrines test results in urine. Six healthy volunteers took a single 2.5-g dose of concentrated Sho-seiryu-to preparation. All urine was collected for 48 h. The concentrations of urinary ephedrines were analyzed by high-performance liquid chromatography and the elimination half-life of the ephedrines was estimated. The results show that ephedrine and cathine (norpseudoephedrine), the prohibited substances of the WADA, were excreted in the urine after taking a single dose of Sho-seiryuto preparation. The peak concentration of ephedrine was 3.88 +/- 1.87 mg/mL (mean +/- SD), which was lower than the WADA permitted value (10 mg/mL). The estimated elimination half-lives of ephedrine, norephedrine, pseudoephedrine, and norpseudoephedrine following administration of this preparation were 5.3 +/- 1.2, 4.9 +/- 0.9, 4.4 +/- 1.0, and 5.4 +/- 1.8 h, respectively. This study concluded that the urine would not violate the antidoping rules after administering a single dose of Sho-seiryu-to preparation. Nevertheless, an applied multiple-dose study upon administering the preparation for three times per day for three days showed a positive urine ephedrine result (13.7 mg/mL). Athletes should be careful when taking more than a single dose of Sho-seiryu-to preparation.
Central Nervous System Stimulants/urine , Drugs, Chinese Herbal/pharmacokinetics , Ephedra/chemistry , Ephedrine/analogs & derivatives , Ephedrine/urine , Medicine, Chinese Traditional , Adult , Biotransformation , Central Nervous System Stimulants/pharmacokinetics , Chromatography, High Pressure Liquid , Doping in Sports , Drugs, Chinese Herbal/administration & dosage , Ephedrine/pharmacokinetics , Female , Half-Life , Humans , Male , Phenylpropanolamine/pharmacokinetics , Phenylpropanolamine/urine
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. This study applied LC-MS-MS to analyze the excretions of three volunteers who ingested oxethazaine and presented positive results for mephentermine and/or phentermine. Thus, oxethazaine is the source of mephentermine and phentermine. Moreover, the results showed that 48 brands of gastric medicines containing oxethazaine were legally imported or locally manufactured in Taiwan, information which could be useful for limiting the misuse of oxethazaine by athletes. The data suggested that the sports associations should warn athletes about the risks of taking oxethazaine.
Antacids/chemistry , Doping in Sports , Ethanolamines/chemistry , Mephentermine/urine , Phentermine/urine , Antacids/administration & dosage , Antacids/pharmacokinetics , Central Nervous System Stimulants/chemistry , Central Nervous System Stimulants/urine , Chromatography, Liquid , Ethanolamines/pharmacokinetics , Female , Humans , Mass Spectrometry , Mephentermine/chemistry , Molecular Structure , Phentermine/chemistry , Sympathomimetics/chemistry , Sympathomimetics/urine , Taiwan
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. The purpose of this study was to investigate the elimination of urinary ephedrines after administering Kakkon-to and to determine the possibility of urinary positive ephedrine test results. Six healthy volunteers took one single dose of 2.5 g Kakkon-to extract granules. The concentrations of urinary ephedrines were analyzed by high-performance liquid chromatography. The result showed that ephedrine and norpseudoephedrine were excreted in the urine after taking one single dose of Kakkon-to. However, the highest amount of ephedrines in urine was ephedrine and the peak concentration was 4.35 +/- 1.82 microg/mL (mean +/- standard deviation), which was lower than the WADA permitted value (10 microg/mL). The estimated elimination half-lives of ephedrine, norephedrine, pseudoephedrine, and norpseudoephedrine following administration of this preparation were: 5.2 +/- 1.2, 4.2 +/- 1.3, 4.2 +/- 0.9, and 6.5 +/- 2.8 h, respectively. This study concluded that the urine would not violate the rule of doping after administering a single dose of Kakkon-to. Nevertheless, a further study on administering the preparation for 3 times per day for 3 days showed a positive ephedrine result. Athletes should be careful when taking more than a single dose of Kakkon-to.
Central Nervous System Stimulants/urine , Drugs, Chinese Herbal/pharmacokinetics , Ephedra/chemistry , Ephedrine/analogs & derivatives , Ephedrine/urine , Biotransformation , Central Nervous System Stimulants/pharmacokinetics , Chromatography, High Pressure Liquid , Doping in Sports , Ephedrine/pharmacokinetics , Half-Life , Humans , Young Adult
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 0.1 to 0.3 microg[sol ]mL at a signal-to-noise ratio of 3. The within-day precision as calculated from the Mahwang TCM preparation and urine samples was below 6.2 and 1.4% for each analyte. The between-day precision as calculated from the Mahwang TCM preparation and urine samples was below 6.8 and 5.9% for each analyte. The between-day accuracy as determined from the Mahwang TCM preparation and urine samples was below 2.2 and 6.8% for each analyte. The recoveries for six compounds, obtained with compounds spiked into the Mahwang TCM preparation and urine, were found to be more than 93.6%. This method can be successfully applied to doping and excretion rate studies.
Chromatography, High Pressure Liquid/methods , Drugs, Chinese Herbal/chemistry , Propanolamines/analysis , Propanolamines/urine , Doping in Sports , Ephedrine/analogs & derivatives , Ephedrine/analysis , Ephedrine/urine , Humans , Phenylpropanolamine/analysis , Phenylpropanolamine/urine , Reproducibility of Results
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. Compared with non-athletes, weightlifters had significantly lower glutathione peroxidase activity and plasma vitamin C concentrations. Weightlifters also had significantly higher malondialdehyde + 4-hydroxy 2-(E)-nonenal (MDA+4-HNE) and thiobarbituric acid-reactive substance (TBARS) levels and creatine kinase (CK) activity. For weightlifters, the plasma vitamin E level and the activity of superoxide dismutase (SOD) decreased, and CK activity increased significantly (P < 0.05) after a 1-week intensive resistance-training regimen. Both the TBARS levels and CK activity returned to values of pre-intensive training after a 2-day rest. The MDA+4-HNE level strongly correlated with CK activity in weightlifters (P < 0.05). In conclusion, both long-term exercise training and 1 week of intensive resistance training resulted in increased oxidative stress and cell injury in female weightlifters. Furthermore, proper rest after intensive training was found to be important for recovery.
Exercise/physiology , Lipid Peroxides/blood , Muscle, Skeletal/injuries , Weight Lifting/physiology , Adolescent , Adult , Antioxidants/metabolism , Creatine Kinase/metabolism , Female , Humans , Muscle, Skeletal/metabolism , Muscle, Skeletal/pathology
