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Effects of natural polyphenol-rich pomegranate juice on the acute and delayed response of Homocysteine and steroidal hormones following weightlifting exercises: a double-blind, placebo-controlled trial.
Ammar, A, MounaTurki, , Trabelsi, K, Bragazzi, NL, Boukhris, O, Bouaziz, M, Ayadi, F, El Abed, K, Driss, T, Souissi, N, et al
Journal of the International Society of Sports Nutrition. 2020;(1):15
Abstract
BACKGROUND Maximal strength-speed exercise is a powerful stimulus to acutely increase concentrations of circulating steroid hormones and homocysteine [Hcy]. There is some evidence that antioxidant beverages rich in polyphenols can attenuate [Hcy] levels and modulate endocrine responses in favor of an anabolic environment. Polyphenols-rich pomegranate (POM) have been reported to possess one of the highest antioxidant capacities compared to other purported nutraceuticals and other food stuffs. Studies focused on proving the beneficial effect of POM consumption during maximal strength exercises have only measured physical performance, muscle damage, oxidative stress and inflammatory responses, while POM effects on [Hcy] and hormonal adaptations are lacking. The aim of the present study was to investigate the effect of consuming natural polyphenol-rich pomegranate juice (POMj) on the acute and delayed [Hcy] and steroidal hormonal responses to a weightlifting exercises session. METHODS Nine elite weightlifters (21.0 ± 1 years) performed two Olympic-weightlifting sessions after ingesting either the placebo (PLA) or POMj supplements. Venous blood samples were collected at rest and 3 min and 48 h after each session. RESULTS Compared to baseline values, circulating cortisol [C] decreased (p < 0.01) and testosterone/cortisol [T/C] ratio increased immediately following the training session in both PLA and POMj conditions (p = 0.003 for PLA and p = 0.02 for POM). During the 48 h recovery period, all tested parameters were shown to recover to baseline values in both conditions with significant increases in [C] and decreases in [T/C] (p < 0.01 for PLA and p < 0.05 for POMj) from 3 min to 48 h post-exercises. Compared to PLA, a lower level of plasma testosterone [T] was registered 3 min post exercise using POMj supplementation (p = 0.012) and a significant decrease (p = 0.04, %change = - 14%) in plasma [Hcy] was registered during the 48 h recovery period only using POMj. A moderate correlation was observed between [Hcy] and [T] responses (p = 0.002, r = - 0.50). CONCLUSION In conclusion, supplementation with POMj has the potential to attenuate the acute plasma [T] response, but did not effect 48 h recovery kinetics of [Hcy] following weightlifting exercise. Further studies investigating androgen levels in both plasma and muscular tissue are needed to resolve the functional consequences of the observed acute POMj effect on plasma [T]. TRIAL REGISTRATION Clinical Trials.gov, ID: NCT02697903. Registered 03 March 2016.
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Acute Caffeine Intake Enhances Mean Power Output and Bar Velocity during the Bench Press Throw in Athletes Habituated to Caffeine.
Wilk, M, Filip, A, Krzysztofik, M, Gepfert, M, Zajac, A, Del Coso, J
Nutrients. 2020;(2)
Abstract
BACKGROUND The main objective of the current investigation was to evaluate the effects of caffeine on power output and bar velocity during an explosive bench press throw in athletes habituated to caffeine. METHODS Twelve resistance trained individuals habituated to caffeine ingestion participated in a randomized double-blind experimental design. Each participant performed three identical experimental sessions 60 min after the intake of a placebo, 3, and 6 mg/kg/b.m. of caffeine. In each experimental session, the participants performed 5 sets of 2 repetitions of the bench press throw (with a load equivalent to 30% repetition maximum (RM), measured in a familiarization trial) on a Smith machine, while bar velocity and power output were registered with a rotatory encoder. RESULTS In comparison to the placebo, the intake of caffeine increased mean bar velocity during 5 sets of the bench press throw (1.37 ± 0.05 vs. 1.41 ± 0.05 and 1.41 ± 0.06 m/s for placebo, 3, and 6 mg/kg/b.m., respectively; p < 0.01), as well as mean power output (545 ± 117 vs. 562 ± 118 and 560 ± 107 W; p < 0.01). However, caffeine was not effective at increasing peak velocity (p = 0.09) nor peak power output (p = 0.07) during the explosive exercise. CONCLUSION The acute doses of caffeine before resistance exercise may increase mean power output and mean bar velocity during the bench press throw training session in a group of habitual caffeine users. Thus, caffeine prior to ballistic exercises enhances performance during a power-specific resistance training session.
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Caffeine and resistance exercise: the effects of two caffeine doses and the influence of individual perception of caffeine.
Polito, MD, Grandolfi, K, de Souza, DB
European journal of sport science. 2019;(10):1342-1348
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Although caffeine is a widely used ergogenic resource, some information regarding its effects on resistance exercises is still lacking. The objective of the present study was to verify the acute effect of the ingestion of two different doses of caffeine on performance during a session of resistance exercises and to analyze the perception of the subjects in relation to the intake of caffeine. Following a double-blind, randomised, cross-over, controlled, and non-placebo design, 14 trained and healthy men (24.7 ± 6.8 years; 79.8 ± 9.8 kg; 177.3 ± 8.5 cm) performed a training session in chest-press, shoulder-press, and biceps curl exercises (3 sets until exhaustion; 70% 1RM; 3 min rest interval; 2 s for each concentric and eccentric phase) on three non-consecutive days after ingestion of 3 mg.kg-1 caffeine (CAF3), 6 mg.kg-1 caffeine (CAF6), or no substance (CON). Subjects were informed that one of the caffeine doses would be placebo. The total number of repetitions performed in CON (93.6 ± 22.4) was significantly lower than in CAF3 (108.0 ± 19.9, P = 0.02) and in CAF6 (109.3 ± 19.8, P = 0.03) and there were no differences between caffeine doses. Eight subjects noticed that caffeine was in CAF3 and six in CAF6 and there were no differences in the number of repetitions between sessions in which the subjects perceived and did not perceive caffeine. In conclusion, caffeine doses of 3 or 6 mg.kg-1 similarly increased performance in resistance upper limb exercises, independent of the subject's perception of substance ingestion.
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Effects of Gua Sha therapy on weightlifting training: a randomized trial.
Wang, X, Jia, B, Zhong, H, Huang, X, Chen, R, Yang, J
Journal of traditional Chinese medicine = Chung i tsa chih ying wen pan. 2019;(4):575-581
Abstract
OBJECTIVE To evaluate the effect of Gua Sha therapy on weightlifting training. METHODS The sample size was calculated by conducting a pilot study. A total of 44 male weightlifters were randomly assigned to either the Gua Sha group (n = 15), sham scraping group (n = 14), or control group (n = 14). The participants in the Gua Sha group and sham scraping group received 16 sessions of Gua Sha therapy during normal weightlifting training for 8 weeks. No treatment was applied to participants in the control group. The effectiveness of Gua Sha therapy was evaluated by measuring weightlifting ability, the rating of perceived exertion (RPE) of snatch and clean and jerk (85% of 1 repetition maximum), and creatinine kinase (CK), blood urea nitrogen (BUN), and immunoglobulin A levels. RESULTS Gua Sha therapy treatment significantly increased weightlifting ability in participants in the Gua Sha group (P < 0.01). The RPE values of snatch and clean and jerk were significantly lower in the Gua Sha group and sham scraping groups compared with the control group (P < 0.05). CK levels were lower and immunoglobulin A levels were significantly higher in the Gua Sha group compared with sham scraping group and control group (both P < 0.05). BUN levels tended to be reduced only in the Gua Sha group. A close correlation between CK levels and the RPE was found in the Gua Sha group. CONCLUSION Gua Sha therapy can facilitate weightlifting ability, reduce the RPE, and inhibit muscle injury by promoting recovery from fatigue caused by normal weightlifting training. Gua Sha therapy could be an effective treatment to complement normal weightlifting training.
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The acute effects of caffeine intake on time under tension and power generated during the bench press movement.
Wilk, M, Krzysztofik, M, Maszczyk, A, Chycki, J, Zajac, A
Journal of the International Society of Sports Nutrition. 2019;(1):8
Abstract
BACKGROUND The ability to generate high levels of power is one of the key factors determining success in many sport disciplines. Although there are studies confirming ergogenic effects of caffeine (CAF) on different physical and mental abilities, much controversy remains about its influence on power. The main goal of this study was to assess the effects of caffeine supplementation on time under tension (TUT) and the number of performed repetitions (REP). The second objective was to determine the effects of CAF supplementation on power (P) and movement velocity (V) during the bench press movement. Additionally the authors evaluated whether CAF has a significant effect on velocity of the bar in the eccentric (ECC) phase (VEMEAN) of the bench press movement. METHODS The study included 20 men (20-31 yrs., 87.3 ± 7.7 kg) with at least 2 years of experience in resistance training. The study participants were divided randomly into two groups: the supplemented group ingested caffeine before exercise (GCAF), while the control group was given a placebo (GCON). The exercise protocol consisted of performing the bench press movement with a load equal to 70%1RM with maximal possible velocity (X/0/X/0). The experimental sets were performed to momentary muscular failure. RESULTS The repeated measures ANOVA between the GCAF and GCON groups revealed statistically significant differences in 2 variables. Post-hoc tests demonstrated statistically significant differences in TUT when comparing the group supplemented with caffeine (13.689 s GCAF) to the one ingesting a placebo (15.332 s GCON) at p = 0.002. Significant differences were also observed in mean velocity during the eccentric phase of movement (0.690 m/s in the GCAF to 0.609 in GCON with p = 0.002). There were no significant differences in generated power and velocity in the CON phase of the movement between the GCAF and GCON. CONCLUSIONS The main finding of the study is that CAF ingestion increases movement velocity of the bar in the eccentric phase of the movement, what results in shortening of the time under tension (TUT) needed for performing a specific number of repetitions, without decreasing power and velocity in the CON phase of the movement.
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Higher- Versus Lower-Intensity Strength-Training Taper: Effects on Neuromuscular Performance.
Pritchard, HJ, Barnes, MJ, Stewart, RJ, Keogh, JW, McGuigan, MR
International journal of sports physiology and performance. 2019;(4):458-463
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PURPOSE To investigate the effects of strength-training tapers of different intensities but equal volume reductions on neuromuscular performance. METHODS Eleven strength-trained men (21.3 [3.3] y, 92.3 [17.6] kg, relative 1-repetition-maximum deadlift 1.9 [0.2] times bodyweight) completed a crossover study. Specifically, two 4-wk strength-training blocks were followed by a taper week with reduced volume (∼70%) involving either increased (5.9%) or decreased (-8.5%) intensity. Testing occurred pretraining (T1), posttraining (T2), and posttaper (T3). Salivary testosterone and cortisol, plasma creatine kinase, a Daily Analysis of Life Demands in Athletes questionnaire, countermovement jump (CMJ), isometric midthigh pull, and isometric bench press were measured. RESULTS CMJ height improved significantly over time (P < .001), with significant increases from T1 (38.0 [5.5] cm) to both T2 (39.3 [5.3] cm; P = .010) and T3 (40.0 [5.3] cm; P = .001) and from T2 to T3 (P = .002). CMJ flight time:contraction time increased significantly over time (P = .004), with significant increases from T1 (0.747 [0.162]) to T2 (0.791 [0.163]; P = .012). Isometric midthigh-pull relative peak force improved significantly over time (P = .033), with significant increases from T1 (34.7 [5.0] N/kg) to T2 (35.9 [4.8] N/kg; P = .013). No significant changes were found between tapers. However, the higher-intensity taper produced small effect-size increases at T3 vs T1 for isometric midthigh-pull relative peak force, CMJ height, and flight time:contraction time, while the lower-intensity taper only produced small effect-size improvements at T3 vs T1 for CMJ height. CONCLUSIONS A strength-training taper with volume reductions had a positive effect on power, with a tendency for the higher-intensity taper to produce more favorable changes in strength and power.
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Effects of placebo on bench throw performance of Paralympic weightlifting athletes: a pilot study.
Costa, GCT, Galvão, L, Bottaro, M, Mota, JF, Pimentel, GD, Gentil, P
Journal of the International Society of Sports Nutrition. 2019;(1):9
Abstract
BACKGROUND The aim of the present study was to analyse the effects of placebo on bench throw performance in Paralympic weightlifting athletes. METHODS The study involved four Paralympic weightlifting male athletes (age: 40.25 ± 9.91 years, weight: 60.5 ± 8.29 kg, height: 1.60 ± 0.15 m) that visited the laboratory in three occasions, separated by 72 h. In the first session, the athletes were tested for bench press one repetition maximum (1RM). The other two sessions were performed in a randomized counter-balanced order and involved bench throw tests performed either after taking placebo while being informed that the capsule contained caffeine or without taking any substance (control). The bench throw tests were performed with loads corresponding to 50, 60, 70 and 80% of the bench press 1RM. RESULTS According to the results, mean velocity (∆: 0.08 m/s, ES 0.36, p < 0.05) and mean propulsive velocity (∆: 0.11 m/s, ES 0.49, p < 0.05) at 50% of 1RM were significantly higher during placebo than control (p < 0.05). However, there were no difference between control and placebo for 60, 70 and 80% of 1RM (p > 0.05). CONCLUSION Our results suggest that placebo intake, when the athletes were informed they were taking caffeine, might be an efficient strategy to improve the performance of explosive movements in Paralympic weightlifting athletes when using low-loads. This brings the possibility of using placebo in order to increase performance, which might reduce the risks associated with ergogenic aids, such as side-effects and positive doping testing.
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Is exercise-induced muscle damage susceptibility body segment dependent? Evidence for whole body susceptibility.
Machado, M, Brown, LE, Augusto-Silva, P, Pereira, R
Journal of musculoskeletal & neuronal interactions. 2013;(1):105-10
Abstract
OBJECTIVE The current study examined serum CK activity following bench press (BP) and leg press (LP) exercise-induced muscle damage to evaluate agreement of subjects classification as either high (HiR) or normal responders (NoR) between upper and lower body muscle groups. METHODS Forty-two men performed two resistance exercise bouts (BP and LP) of four sets of maximum repetitions to concentric failure at 10RM, following a random design. RESULTS Fourteen subjects were classified as HiR after the BP and thirteen subjects after LP, while nine subjects were classified as HiR for both exercises. The analysis revealed good agreement (Kappa=0.528, with SE=0.137 and 95% confidence interval: from 0.259 to 0.798). Additionally, we found a significant moderate correlation (r=0.65, p<0.001) between CK peaks obtained following LP and BP. CONCLUSION Our results suggest that exercise-induced muscle damage susceptibility is a whole body characteristic and is not body segment dependent. Thus, it may be that genetic or systemic mechanisms explain individual variation in muscle damage susceptibility.
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Rapid aminoacidemia enhances myofibrillar protein synthesis and anabolic intramuscular signaling responses after resistance exercise.
West, DW, Burd, NA, Coffey, VG, Baker, SK, Burke, LM, Hawley, JA, Moore, DR, Stellingwerff, T, Phillips, SM
The American journal of clinical nutrition. 2011;(3):795-803
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BACKGROUND Ingestion of whey or casein yields divergent patterns of aminoacidemia that influence whole-body and skeletal muscle myofibrillar protein synthesis (MPS) after exercise. Direct comparisons of the effects of contrasting absorption rates exhibited by these proteins are confounded by their differing amino acid contents. OBJECTIVE Our objective was to determine the effect of divergent aminoacidemia by manipulating ingestion patterns of whey protein alone on MPS and anabolic signaling after resistance exercise. DESIGN In separate trials, 8 healthy men consumed whey protein either as a single bolus (BOLUS; 25-g dose) or as repeated, small, "pulsed" drinks (PULSE; ten 2.5-g drinks every 20 min) to mimic a more slowly digested protein. MPS and phosphorylation of signaling proteins involved in protein synthesis were measured at rest and after resistance exercise. RESULTS BOLUS increased blood essential amino acid (EAA) concentrations above those of PULSE (162% compared with 53%, P < 0.001) 60 min after exercise, whereas PULSE resulted in a smaller but sustained increase in aminoacidemia that remained elevated above BOLUS amounts later (180-220 min after exercise, P < 0.05). Despite an identical net area under the EAA curve, MPS was elevated to a greater extent after BOLUS than after PULSE early (1-3 h: 95% compared with 42%) and later (3-5 h: 193% compared with 121%) (both P < 0.05). There were greater changes in the phosphorylation of the Akt-mammalian target of rapamycin pathway after BOLUS than after PULSE. CONCLUSIONS Rapid aminoacidemia in the postexercise period enhances MPS and anabolic signaling to a greater extent than an identical amount of protein fed in small pulses that mimic a more slowly digested protein. A pronounced peak aminoacidemia after exercise enhances protein synthesis. This trial was registered at clinicaltrials.gov as NCT01319513.
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The effect of caffeine ingestion on mood state and bench press performance to failure.
Duncan, MJ, Oxford, SW
Journal of strength and conditioning research. 2011;(1):178-85
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Research has suggested that caffeine enhances aerobic performance. The evidence for high-intensity, short-term exercise, particularly resistance exercise is mixed and has not fully examined the psychological changes that occur after this mode of exercise with caffeine ingestion. This study examined the effect of caffeine (5 mg · kg(-1)) vs. placebo on bench press exercise to failure and the mood state response pre to postexercise. Thirteen moderately trained men (22.7 ± 6.0 years) completed 2 laboratory visits, after determination of 1 repetition maximum (1RM) on the bench press, where they performed bench press repetitions to failure at a load of 60% 1RM. Mood state was assessed 60 minutes pre and immediately post-substance ingestion. Borg's rating of perceived exertion (RPE) and peak blood lactate (PBla) were assessed after each test, and peak heart rate (PHR) was determined using heart rate telemetry. Participants completed significantly more repetitions to failure (p = 0.031) and lifted significantly greater weight (p = 0.027) in the caffeine condition compared to the placebo condition. The PHR (p = 0.0001) and PBla (p = 0.002) were higher after caffeine ingestion. The RPE was not different across conditions (p = 0.082). Mood state scores for vigor were greater (p = 0.001) and fatigue scores lower (p = 0.04) in the presence of caffeine. Fatigue scores were greater postexercise (p = 0.001) compared to scores pre exercise across conditions. Caffeine ingestion enhances performance in short-term, resistance exercise to failure and may favorably change the mood state response to exercise compared to a placebo.