scholarly journals The Effects of High Doses of Caffeine on Maximal Strength and Muscular Endurance in Athletes Habituated to Caffeine

Nutrients ◽  
2019 ◽  
Vol 11 (8) ◽  
pp. 1912 ◽  
Author(s):  
Michal Wilk ◽  
Michal Krzysztofik ◽  
Aleksandra Filip ◽  
Adam Zajac ◽  
Juan Del Coso
Keyword(s):  
Body Mass ◽  
Repeated Measures ◽  
Bench Press ◽  
Muscle Endurance ◽  
Experimental Session ◽  
Maximal Strength ◽  
Double Blind ◽  
Significant Difference ◽  
Endurance Tests ◽  
Double Blind Design

Background: The main goal of this study was to assess the acute effects of the intake of 9 and 11 mg/kg/ body mass (b.m.) of caffeine (CAF) on maximal strength and muscle endurance in athletes habituated to caffeine. Methods: The study included 16 healthy strength-trained male athletes (age = 24.2 ± 4.2 years, body mass = 79.5 ± 8.5 kg, body mass index (BMI) = 24.5 ± 1.9, bench press 1RM = 118.3 ± 14.5 kg). All participants were habitual caffeine consumers (4.9 ± 1.1 mg/kg/b.m., 411 ± 136 mg of caffeine per day). This study had a randomized, crossover, double-blind design, where each participant performed three experimental sessions after ingesting either a placebo (PLAC) or 9 mg/kg/b.m. (CAF-9) and 11 mg/kg/b.m. (CAF-11) of caffeine. In each experimental session, participants underwent a 1RM strength test and a muscle endurance test in the bench press exercise at 50% 1RM while power output and bar velocity were measured in each test. Results: A one-way repeated measures ANOVA revealed a significant difference between PLAC, CAF-9, and CAF-11 groups in peak velocity (PV) (p = 0.04). Post-hoc tests showed a significant decrease for PV (p = 0.04) in the CAF-11 compared to the PLAC group. No other changes were found in the 1RM or muscle endurance tests with the ingestion of caffeine. Conclusion: The results of the present study indicate that high acute doses of CAF (9 and 11 mg/kg/b.m.) did not improve muscle strength nor muscle endurance in athletes habituated to this substance.

scholarly journals The effects of different doses of caffeine on maximal strength and strength-endurance in women habituated to caffeine

2020 ◽  
Author(s):  
Michal Wilk ◽  
Aleksandra Filip ◽  
Michal Krzysztofik ◽  
James J. Tufano ◽  
Adam Zajac ◽  
...  
Keyword(s):  
Body Mass ◽  
Bench Press ◽  
Endurance Performance ◽  
Caffeine Intake ◽  
Experimental Session ◽  
Maximal Strength ◽  
Endurance Test ◽  
Double Blind ◽  
Maximal Load ◽  
Main Effect

Abstract PurposeThe main goal of this study was to assess the acute effects of 3 and 6 mg of caffeine intake per kg of body mass (b.m.) on maximal strength and strength-endurance in women habituated to caffeine. MethodsTwenty-one healthy resistance-trained female university students (23.0±0.9 years, body mass: 59.0±6.6 kg), with a daily caffeine intake of 5.8±2.6 mg/kg/b.m. participated in a randomized, crossover, double-blind design. Each participant performed three experimental sessions after ingesting either a placebo (PLAC) or 3 mg/kg/b.m. (CAF-3) and 6 mg/kg/b.m. (CAF-6) of caffeine. In each experimental session, the participants underwent a 1RM test and a strength-endurance test at 50%1RM in the bench press exercise. Maximal load was measured in the 1RM test and the time under tension, number of preformed repetitions, power output and bar velocity were registered in the strength-endurance test. ResultsThe one-way ANOVA showed a main effect of caffeine on 1RM bench press performance (F=14.74; p<0.01). In comparison to the PLAC (40.48±9.21 kg), CAF-3 (41.68±8.98 kg; p=0.01) and CAF-6 (42.98±8.79 kg; p<0.01) increased 1RM bench press test results. There was also a main effect of caffeine on time under tension during the strength-endurance test (F=13.09; p<0.01). In comparison to the PLAC (53.52±11.44 s), CAF-6 (61.76±15.39 s; p<0.01) significantly increased the time under tension during the maximal strength-endurance test. ConclusionAn acute dose of 3-to-6 mg/kg/b.m. of caffeine improves maximum muscle strength. However, the effect of these doses had minimal ergogenic effect on strength-endurance performance.

scholarly journals The effects of different doses of caffeine on maximal strength and strength‐endurance in women habituated to caffeine

2021 ◽  
Vol 18 (1) ◽  
Author(s):  
Aleksandra Filip-Stachnik ◽  
Michal Wilk ◽  
Michal Krzysztofik ◽  
Ewelina Lulińska ◽  
James J. Tufano ◽  
...  
Keyword(s):  
Body Mass ◽  
Bench Press ◽  
Endurance Performance ◽  
Caffeine Intake ◽  
Experimental Session ◽  
Maximal Strength ◽  
Endurance Test ◽  
Double Blind ◽  
Maximal Load ◽  
Main Effect

Abstract Purpose The main goal of this study was to assess the acute effects of 3 and 6 mg of caffeine intake per kg of body mass (b.m.) on maximal strength and strength-endurance in women habituated to caffeine. Methods Twenty-one healthy resistance-trained female students (23.0 ± 0.9 years, body mass: 59.0 ± 6.6 kg), with a daily caffeine intake of 5.8 ± 2.6 mg/kg/b.m. participated in a randomized, crossover, double-blind design. Each participant performed three experimental sessions after ingesting either a placebo (PLAC) or 3 mg/kg/b.m. (CAF-3) and 6 mg/kg/b.m. (CAF-6) of caffeine. In each experimental session, the participants underwent a 1RM test and a strength-endurance test at 50 %1RM in the bench press exercise. Maximal load was measured in the 1RM test and the time under tension, number of preformed repetitions, power output and bar velocity were registered in the strength-endurance test. Results The one-way ANOVA showed a main effect of caffeine on 1RM bench press performance (F = 14.74; p < 0.01). In comparison to the PLAC (40.48 ± 9.21 kg), CAF-3 (41.68 ± 8.98 kg; p = 0.01) and CAF-6 (42.98 ± 8.79 kg; p < 0.01) increased 1RM bench press test results. There was also a significant increase in 1RM for CAF-6 when compared to CAF-3 (p < 0.01). There was a main effect of caffeine on time under tension during the strength-endurance test (F = 13.09; p < 0.01). In comparison to the PLAC (53.52 ± 11.44 s), CAF-6 (61.76 ± 15.39 s; p < 0.01) significantly increased the time under tension during the maximal strength-endurance test. Conclusion An acute dose of 3-to-6 mg/kg/b.m. of caffeine improves maximum strength. However, these doses of caffeine had minimal ergogenic effect on strength-endurance performance in women habituated to caffeine.

The acute effects of a low and high dose of oral l-arginine supplementation in young active males at rest

2011 ◽  
Vol 36 (3) ◽  
pp. 405-411 ◽  
Author(s):  
Scott C. Forbes ◽  
Gordon J. Bell
Keyword(s):  
Body Mass ◽  
Repeated Measures ◽  
Plasma Concentrations ◽  
Insulin Response ◽  
High Dose ◽  
Placebo Condition ◽  
Double Blind ◽  
Physically Active ◽  
Significant Difference ◽  
Arginine Supplementation

l-arginine (2-amino-5-guanidinovaleric acid) is a conditionally essential amino acid. Intravenous (IV) administration of l-arginine invokes a large metabolic (nitrate/nitrite (NOx)) and hormonal (growth hormone (GH), insulin-like growth factor 1 (IGF-1), and insulin) response; however, research examining oral l-arginine supplementation is conflicting, potentially owing to dose. The purpose of this study was examine a low and high dose of oral l-arginine on blood l-arginine, NOx, GH, IGF-1, and insulin response. Fourteen physically active males (age: 25 ± 5 years; weight: 78.0 ± 8.5 kg; height: 179.4 ± 4.7 cm) volunteered to be in a randomized, double-blind, repeated-measures study. Following an overnight fast, an IV catheter was placed in a forearm vein and a resting blood sample was drawn at ∼0800 hours. Each subject was then provided 1 of 3 treatment conditions (placebo, low (0.075 g·kg–1 of body mass), or high (0.15 g·kg–1 of body mass of l-arginine)). Blood samples were drawn at 30, 60, 90, 120, and 180 min after consumption. l-arginine plasma concentrations significantly increased (p < 0.001) to a similar level at any time point in both the low- and high-dose conditions; there was no change over time in the placebo condition. There was no significant difference between conditions for NOx, GH, IGF-1, or insulin. Based on these findings, a low dose of l-arginine was just as effective at increasing plasma l-arginine concentrations as a high dose; however, neither dose was able to promote a significant increase in NOx, GH, IGF-1, or insulin at rest.

scholarly journals Acute effects of two caffeine doses on bar velocity during the bench press exercise among women habituated to caffeine: a randomized, crossover, double-blind study involving control and placebo conditions

2021 ◽  
Author(s):  
Aleksandra Filip-Stachnik ◽  
Michal Krzysztofik ◽  
Juan Del Coso ◽  
Michal Wilk
Keyword(s):  
Repeated Measures ◽  
Bench Press ◽  
Biological Effects ◽  
Experimental Session ◽  
Double Blind Study ◽  
Mean Velocity ◽  
Double Blind ◽  
Caffeine Ingestion ◽  
Training Outcomes ◽  
Bar Velocity

Abstract Purpose The main goal of this study was to evaluate the effectiveness of two different doses of caffeine (3 and 6 mg/kg) to enhance bar velocity during the bench press in women habituated to caffeine. Methods Twelve recreationally trained women (age: 23.3 ± 0.8 years, body mass: 60.7 ± 5.7 kg, bench press one-repetition maximum (1RM): 44.3 ± 7.8 kg, daily caffeine ingestion: 5.7 ± 2.0 mg/kg/day) participated in a randomized double-blind experimental design. Each participant performed four different experimental sessions: after no supplementation (control, CON), after ingesting 3 and 6 mg/kg of caffeine (CAF-3 and CAF-6, respectively), or after ingesting a placebo (PLAC). In each experimental session, the participants performed 3 sets of 3 repetitions of the bench press exercise at 50% 1RM. Results A two-way repeated-measures ANOVA with subsequent post hoc analyses indicated significant increases in peak velocity (p < 0.01; ES = 0.91) and mean velocity (p < 0.01; ES = 0.78) after the intake of CAF-6 compared to CON. The study did not show significant differences in bar velocity between CAF-6 and PLAC and between CAF-3 and PLAC. No significant differences in bar velocity were observed between CAF-3 and CAF-6 conditions. Conclusion These results suggest that 6 mg/kg of caffeine can be an effective dose to improve power-specific training outcomes in women habituated to caffeine. However, the ergogenic effect of 6 mg/kg of caffeine may be derived from a combination of biological effects and expectancy, as this dose was only superior to the control condition with no differences over the placebo.

Comparison of CrossFit Barbara and classic resistance trainings for the protection of strength performance during off-season in kickboxers

2020 ◽  
pp. 1-8
Author(s):  
Cebrail Gençoğlu ◽  
İlhan Şen
Keyword(s):  
Resistance Training ◽  
Body Mass ◽  
Body Fat ◽  
Bench Press ◽  
Body Fat Percentage ◽  
Fat Percentage ◽  
Strength Performance ◽  
Significant Difference ◽  
Before And After ◽  
Push Up

BACKGROUND: The inability of athletes to train or the decrease in the intensity and frequency of training may cause athletes to lose performance. Particularly in view of the current COVID-19 pandemic, maintaining strength outside the normal framework provides an advantage to athletes for the next competitions. OBJECTIVE: To compare the CrossFit Barbara which can be applied easily at home during the off-season or some situations such as the epidemic limitation to classic resistance training methods used to maintain the strength performance of national kickboxers. METHODS: Forty-three national kickboxers, CrossFit (CF, n= 22), and resistance training (RT, n= 21), participated in this study. While CF performed 20 pull-ups, 30 push-ups, 40 sit-ups, and 50 squat exercises, RT performed bench press, lat pull down, leg press, biceps curl, and triceps extension exercises twice per week for six weeks. Before and after the six weeks, the following variables were measured; body mass (BM) and body fat percentage (FP), VO2max, bench press (BP), squat (SQ), leg strength (LS), hand grip strength (HGS), pull-up, push-up and counter movement jump (CMJ). RESULTS: BP (p< 0.001, F= 41.125, ηp2= 0.501), SQ (p< 0.001, F= 26.604, ηp2= 0.394), LS (p< 0.001, F= 15.234, ηp2= 0.271), push-up (p< 0.001, F= 31.978, ηp2= 0.438) and pull-up (p< 0.001, F= 24.410, ηp2= 0.373) values changed significantly in group-time interaction between CF and RT groups, while there was no significant difference for the BM (p= 0.198, F= 1.715, ηp2= 0.040), Fat (p= 0.265, F= 1.279, ηp2= 0.030), HGS (p= 0.665, F= 0.190, ηp2= 0.005, CMJ (p= 0.054, F= 3.946, ηp2= 0.088) and VO2max (p=0.747, F= 0.106, ηp2= 0.003). Furthermore, according to the before and after study values, BP, SQ, LS, and CMJ decreased significantly (p< 0.05) while BM, FP, HGS, VO2max, pull-up and push-up variables did not in the CF (p> 0.05). In the RT, the pull-up and push-up variables decreased significantly (p< 0.05) while there was no significant difference for BP, SQ, LS, HGS, VO2max, body mass, body fat percentage and CMJ (p> 0.05). CONCLUSION: CF Barbara workout was more effective in maintaining strength endurance performances, and RT in maintaining maximum strength performances. According to the individual performance needs of athletes, reasonable training method can be used to prevent performance decrement in the strength domain.

Effects of acute caffeine withdrawal on habituated male runners

1994 ◽  
Vol 76 (3) ◽  
pp. 1043-1048 ◽  
Author(s):  
R. K. Hetzler ◽  
N. Warhaftig-Glynn ◽  
D. L. Thompson ◽  
E. Dowling ◽  
A. Weltman
Keyword(s):  
Repeated Measures ◽  
Lactate Threshold ◽  
Substrate Utilization ◽  
Caffeine Intake ◽  
Loading Dose ◽  
Testing Session ◽  
O2 Uptake ◽  
Double Blind ◽  
Caffeine Withdrawal ◽  
Double Blind Design

This study investigated the effects of caffeine withdrawal on six trained caffeine-habituated male runners: age 29.8 +/- 5.8 (SD) yr, height 180.4 +/- 5.4 cm, weight 77.3 +/- 6.7 kg, maximal O2 uptake 63.0 +/- 5.4 ml.kg-1.min-1, and daily caffeine intake 674 +/- 128 mg. The subjects received a loading dose (5 mg/kg body wt) of caffeine 48 h before each testing session. They were then given (using a repeated-measures double-blind design) additional doses of caffeine (5 mg/kg body wt) or a placebo 36, 24, 12, and 2 h before testing. They ran at a velocity corresponding to their lactate threshold for 60 min in a caffeine withdrawal or caffeinated condition. Caffeine withdrawal resulted in no significant differences in absolute O2 uptake, O2 uptake relative to maximal O2 uptake, respiratory exchange ratios, or free fatty acid concentrations. Glycerol concentrations were significantly attenuated in the withdrawal condition. No significant differences were revealed in calculated substrate utilization. It was concluded that caffeine withdrawal significantly affects lipolysis but not substrate utilization during prolonged running.

scholarly journals The Effect of Extract Supplements of Moringa Oleifera Leaves Plus Royal Jelly on Hemoglobin (Hb) Levels of Anemia Pregnant Mother in Takalar Regency

2020 ◽  
Vol 1 (2) ◽  
pp. 22-29
Author(s):  
Yulni Yulni ◽  
Veni Hadju ◽  
Burhanuddin Bahar ◽  
Citrakesumasari Citrakesumasari ◽  
Rahayu Indriasari ◽  
...  
Keyword(s):  
Pregnant Women ◽  
Leaf Extract ◽  
Moringa Oleifera ◽  
Royal Jelly ◽  
P Value ◽  
Double Blind ◽  
Significant Difference ◽  
Before And After ◽  
The Difference ◽  
Double Blind Design

The aim of this study was to determine the effect of Moringa oleifera leaf extract supplements, Moringa oleifera leaf extract plus royal jelly and placebo on hemoglobin levels in anemic pregnant women. This research is a randomized controlled double blind design study which was conducted in Polombangkeng Utara District, Takalar Regency for 2 months. The subjects of this study were pregnant women with anemia, the majority of which were 20-35 years old, primigravida parity, income less than UMR, unemployment, higher education, pregnancy distance of more than 2 years with p value> 0.05. Then divided into three groups, namely Moringa capsules plus royal jelly (KRJ) (n = 24), Moringa capsules (KTR) (n = 24) and placeco (PLC) (n = 21). Before and after the intervention, measurements of hemoglobin levels were carried out using the Hemocue tool and interviewing the characteristics of the respondents. The results showed that the average Hb level increased from each group (mean SD): KRJ 10.06 ± 0.75 to 11.42 ± 1.23, P = 0.001, KTR 10.40 ± 0.46 to 11.15 ± 0 , 90 P = 0.001 and PLC 10.43 ± 0.42 becomes 11.14 ± 0.88 P = 0.002. but there was no significant difference from the difference in the average increase in Hb levels in the three groups, but there was a tendency that KRJ was superior to the KTR and PLC groups with an increase of 1.36 gr / dl, KTR 0.75 gr / dl and PLC 0.71 gr / dl. So it can be concluded that KRJ is better than KTR and PLC in increasing Hb levels in anemic pregnant women in Takalar Regency.

scholarly journals Evaluation of the Effects of 660-nm and 810-nm Low-Level Diode Lasers on the Treatment of Dentin Hypersensitivity

2020 ◽  
Vol 11 (2) ◽  
pp. 126-134
Author(s):  
Narges Naghsh ◽  
Mahdi Kachuie ◽  
Marzie Kachuie ◽  
Reza Birang
Keyword(s):  
Diode Laser ◽  
Repeated Measures ◽  
Diode Lasers ◽  
Tooth Surface ◽  
Control Group ◽  
Dentin Hypersensitivity ◽  
Double Blind ◽  
Group I ◽  
Significant Difference ◽  
Laser Group

Introduction: Dentin hypersensitivity is a common oral problem that occurs as a short and sharp pain. There are many techniques to treat this condition, the latest of which is laser treatment. The aim of this study was to evaluate the effect of two types of low-power diode lasers (660 nm and 810 nm) on dentin hypersensitivity in order to achieve an acceptable clinical application by adjusting the effective parameters. Methods: In this randomized, double-blind clinical trial, sensitive teeth of 7 patients were divided into three groups with a randomized matching method: group I, treated with 660-nm diode laser irradiation, group II, treated with diode laser 810-nm, and group III, the control group. Irradiation parameters for 660-nm and 810-nm diode lasers were the power of 30 mW and 100 mW respectively, in contact and continuous modes, perpendicular to the tooth surface with a sweeping motion. Treatments were carried out in four sessions at weekly intervals. The data obtained were analyzed with SPSS 22, using one-way repeated measures ANOVA and the LSD (least significant difference) test. The significance level was considered as P≤0.05. Results: There were no significant differences in visual analogue scale (VAS) score changes between the two laser groups after the intervention in the first, second and third weeks compared to the baseline (P>0.05). These changes in the fourth week were significantly higher in the 810-nm laser group compared to the 660-nm laser group (P=0.04), and in the 660-nm laser group, they were more than the control group (P=0.02). The mean VAS scores at 1-week, 1-month and 2-month postoperative intervals were significantly lower in the 810-nm laser group than in the 660-nm laser group, and in the 660-nm laser group, they were less than the control group (P<0.001). Conclusion: The use of 660-nm and 810-nm diode lasers with the power of 30 and 100 mW respectively for 120 seconds was effective in reducing pain in patients with dentin hypersensitivity. However, the effect of the 810-nm laser on reducing the dentin hypersensitivity was more long-lasting than that of the 660-nm laser.

Carbohydrate mouth rinsing improves resistance training session performance

2018 ◽  
Vol 13 (5) ◽  
pp. 804-809 ◽  
Author(s):  
Luciana S Decimoni ◽  
Victor M Curty ◽  
Livia Almeida ◽  
Alexander J Koch ◽  
Jeffrey M Willardson ◽  
...  
Keyword(s):  
Resistance Exercise ◽  
Exercise Performance ◽  
Repeated Measures ◽  
Perceived Exertion ◽  
Bench Press ◽  
Statistical Significance ◽  
Training Session ◽  
Rating Of Perceived Exertion ◽  
Double Blind ◽  
Mouth Rinsing

We investigated the effect of carbohydrate mouth rinsing on resistance exercise performance. Fifteen recreationally trained women (age 26 ± 4 y; height 1.61.9 ± 5.1 m; weight 59.5 ± 8.2 kg) completed two resistance exercise bouts consisting of three sets of five exercises (half-squat, leg press, bench press, military press, and seated row) to volitional fatigue with a 10 repetition-maximum load. Immediately prior to and during the middle of each exercise bout, subjects mouth rinsed for 10 s with 100 mL of either a 6% maltodextrin solution (CHO) or an artificially flavored solution (PLA) in a randomized, double-blind, counterbalanced fashion. Heart rate and perceived exertion were compared between conditions using a 2 (conditions) × 15 (time points) repeated measures ANOVA. Significant main effects were further analyzed using pairwise comparisons with Bonferroni post hoc tests. Total volume (exercises * sets * repetitions * load) between sessions was compared with a Student’s t-test. Statistical significance was set at p ≤ 0.05 level of confidence. The CHO resulted in more repetitions performed during half-squat, bench press, military press, and seated row, for a significantly greater (∼12%) total volume load lifted versus PLA ( p = 0.039, ES: 0.49). Rating of perceived exertion was also significantly lower in the CHO versus PLA ( p = 0.020, ES: 0.28). These data indicate that CHO mouth rinsing can enhance high-volume resistance exercise performance and lower ratings of perceived exertion.

scholarly journals Effects of Single versus Multiple Bouts of Resistance Training on Maximal Strength and Anaerobic Performance

2018 ◽  
Vol 62 (1) ◽  
pp. 231-240 ◽  
Author(s):  
Kai Shiau ◽  
Te Hung Tsao ◽  
Chang Bin Yang
Keyword(s):  
Resistance Training ◽  
Resistance Exercise ◽  
Bench Press ◽  
Upper Body ◽  
Anaerobic Performance ◽  
Maximal Strength ◽  
Post Intervention ◽  
Significant Difference ◽  
Single Bout ◽  
Before And After

Abstract This study examined the effects of one single bout daily versus triple bouts of resistance exercise for 12 weeks on muscular strength and anaerobic performance of the upper body. Twenty young male adults (age: 22.0 ± 1.0 years, bench press: 44.0 ± 10.3 kg) were randomly assigned to a single bout (SB) or triple bouts (TB) of resistance exercise group. Maximal strength and anaerobic performance of the upper body using the bench press (one-repetition maximum) and the modified 30 s Wingate test were determined before and after the intervention. Additionally, changes in lactate levels before and after the Wingate test were measured. Although the SB and TB groups showed a significant increase in maximal strength (post-intervention, SB: 67.2 ± 9.2 and TB: 67.6 ± 7.6 kg, respectively) compared with the values at pre-intervention (SB: 44.6 ± 11.4 and TB: 43.9 ± 8.7 kg, respectively), there was no significant difference for this variable between the two groups post-intervention (p > 0.05). The anaerobic performance of the upper body in the SB and TB groups also displayed improvements without significant difference between the two groups after the completion of different training regimes. On the basis of the same training volume, multiple bouts of resistance training showed similar improvements in maximal strength and anaerobic performance to one bout of resistance training in young adult men without prior experience in resistance training

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