Placebo Ingestion Research Articles

The effects of 3-month supplementation with synbiotic on patient-reported outcomes, exercise tolerance, and brain and muscle metabolism in adult patients with post-COVID-19 chronic fatigue syndrome (STOP-FATIGUE): a randomized Placebo-controlled clinical trial.

Considering the observed gastrointestinal issues linked to post-COVID-19 myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS), beneficially modulating the gut microbiota could offer a safe, cost-effective nutritional strategy. This trial aimed to evaluate the effects of medium-term synbiotic supplementation on patient-reported outcomes, exercise tolerance, and tissue metabolism in patients with post-COVID-19 ME/CFS. Between September 2022 and December 2023, we investigated the impact of 3-month supplementation with a synbiotic mixture including L. rhamnosus DSM 32550, Humiome® L. plantarum DSM 34532, B. lactis DSM 32269, B. longum DSM 32946, fructooligosaccharides and zinc, on predetermined primary and secondary outcome measures in twenty six post-COVID-19 ME/CFS patients utilizing a parallel-group, randomized, placebo-controlled, double-blind design. Both the synbiotic and placebo intake resulted in a significant reduction in general fatigue after 3months compared to the baseline values (P ≤ 0.05). This was accompanied by a significant interaction effect (time vs. treatment) for post-exercise malaise (P = 0.02), with synbiotic superior to placebo to attenuate post-exercise malaise. The synbiotic also demonstrated a significant advantage over placebo in increasing choline levels at the thalamus (P = 0.02), and creatine levels at left frontal white matter (P = 0.05) and left frontal grey matter (P = 0.04). Taking the synbiotic mixture for three months improves tissue metabolism and mitigates clinical features of post-COVID-19 fatigue syndrome. The presented data show promise in addressing the widespread issue of ME/CFS following the COVID-19 pandemic; however, further validation is needed before endorsing the synbiotics within this clinical context. The study is registered at ClinicalTrials.gov (NCT06013072).

Evaluation of daily supplementation of fertitonex on different semen parameters in idiopathic male infertility: a randomized double blind placebo controlled cross over study.

The study aimed to evaluate the effect of fertitonex containing L-carnitine L-tartrate together with other micronutrients on different semen parameters in idiopathic male infertility as well as male reproductive hormones. 100 randomized infertile patients were recruited from July 2023 to February 2024. They were randomized into two groups. Group (A) received fertitonex twice daily for the first 3months. Group (B) received placebo twice daily for the first 3months. Crossover was done after 1month wash-out period for additional 3months. Group (A) who started fertitonex first showed significant improvement in sperms concentration and motility and progressive motility as well as significant reduction in abnormal forms after 3months from beginning the study (p < 0.001, p < 0.001, p < 0.001, p < 0.001, respectively). Interestingly, these improvements continued for additional 3months after placebo intake (p < 0.001, p 0.005, p < 0.001, p < 0.001, respectively). Group (B) who started placebo first showed significant improvement in sperms concentration and motility and progressive motility as well as significant reduction in abnormal forms after 6months from beginning the study (p < 0.001, p < 0.001, p < 0.001, p < 0.001, respectively). LH level was significantly higher among group (A) compared to group (B) at baseline and 3months and 6months (p value 0.02, 0.032. 0.024, respectively). We finally concluded that fertitonex is an effective, tolerable and safe drug that can be used for treating idiopathic male infertility.

Effects of Phenylcapsaicin on Intraocular and Ocular Perfusion Pressure During a 30-Min Cycling Task: A Placebo-Controlled, Triple-Blind, Balanced Crossover Study.

The main objective of this placebo-controlled, triple-blind, balanced crossover study was to assess the acute effects of phenylcapsaicin (PC) intake (2.5mg) on intraocular pressure (IOP), ocular perfusion pressure (OPP), and heart rate (HR) during a 30-min cycling task performed at 15% of the individual maximal power. Twenty-two healthy young adults performed the cycling task 45min after ingesting PC or placebo. IOP was measured with a rebound tonometer before exercise, during cycling (every 6min), and after 5 and 10min of recovery. OPP was assessed before and after exercise. HR was monitored throughout the cycling task. We found an acute increase of IOP levels related to PC consumption while cycling (mean difference = 1.91 ± 2.24mmHg; p = .007, ηp2=.30), whereas no differences were observed for OPP levels between the PC and placebo conditions (mean difference = 1.33 ± 8.70mmHg; p = .608). Mean HR values were higher after PC in comparison with placebo intake (mean difference = 3.11 ± 15.87 bpm, p = .019, ηp2=.24), whereas maximum HR did not differ between both experimental conditions (p = .199). These findings suggest that PC intake before exercise should be avoided when reducing IOP levels is desired (e.g.,glaucoma patients or those at risk). Future studies should determine the effects of different ergogenic aids on IOP and OPP levels with other exercise configurations and in the long term.

Acute and prolonged ketosis lower serum IGF-I levels in human subjects

ObjectiveMetabolic health and longevity are influenced by numerous factors including the growth hormone (GH) – insulin-like growth factor I (IGFI) axis and ketone bodies (KB). However, data on the impact of KB exposure on GH and IGF-I levels are few. Design and patientsTo investigate the effect of acute and chronic KB exposure on GH and IGF-I levels in human subjects. GH and IGF-I levels were measured in three human studies: i) After a single oral ingestion of KB (36.5 g of Na-D/L-βOHB) vs. placebo in six healthy individuals; ii): after a three-week isocaloric ketogenic diet (KD) compared to a standard diet (SD) in 11 overweight individuals; and iii) in a genetic predisposition study using the specific genetic variants in the SCOT gene (rs7712274 and rs7728482), which is associated with ketonuria. ResultsA single oral KB ingestion significantly lowered serum IGF-I with 33 ng/ml (KB ingestion) vs 15 ng/ml (placebo), P = 0.01. Ketogenic diet significantly lowered serum IGF-I levels 111 ng/ml (KD) vs 125 ng/ml (SD), P = 0.01 in combination with a two-fold increase in serum GH 0.9 ng/ml to 1.8 ng/ml (KD) compared to 0.9 ng/ml to 0.4 ng/ml (SD), P = 0.03. Individuals with genetic predisposition to ketonuria had lower levels of IGF-I (β = −0.0068, SE = 0.0029, P = 0.02). ConclusionsKB exposure is associated with reduced serum IGF-I levels in the presence of non-suppressed or elevated GH levels. This observation points to a suppressive effect of KB on hepatic IGF-I production. The association between genetic predisposition to ketonuria and increased body size is unexpected and deserves further investigations.

Influence of the CYP1A2 c.-163A > C polymorphism in the effect of caffeine on fat oxidation during exercise: a pilot randomized, double-blind, crossover, placebo-controlled trial.

The aim of this study was to determine the influence of the CYP1A2 c.-163A > C (rs762551) polymorphism on the effect of oral caffeine intake on fat oxidation during exercise. Using a pilot randomized, double-blind, crossover, placebo-controlled trial, 32 young and healthy individuals (women = 14, men = 18) performed an incremental test on a cycle ergometer with 3-min stages at workloads from 30 to 70% of maximal oxygen uptake (VO2max). Participants performed this test after the ingestion of (a) placebo; (b) 3mg/kg of caffeine; (c) 6mg/kg of caffeine. Fat oxidation rate during exercise was measured by indirect calorimetry. The influence of the CYP1A2 c.-163A > C polymorphism in the effect of caffeine on fat oxidation rates during exercise was established with a three-way ANOVA (substance × genotype × intensity). Eight participants were genotyped as AA, 18 participants were CA heterozygotes, and 6 participants were CC. There was a main effect of substance (F = 3.348, p = 0.050) on fat oxidation rates during exercise with no genotype effect (F = 0.158, p = 0.959). The post hoc analysis revealed that, in comparison to the placebo, 3 and 6mg/kg of caffeine increased fat oxidation at 40-50% VO2max in AA (all p < 0.050) and 50-60% VO2max in CA and CC participants (all p < 0.050). Oral intake of 3 and 6mg/kg of caffeine increased fat oxidation rate during aerobic exercise in individuals with AA, CA and CC genotypes. This suggests that the effect of caffeine to enhance fat oxidation during exercise is not influenced by the CYP1A2 c.-163A > C polymorphism. The study was registered on clinicaltrials.gov with ID: NCT05975489.

Acute Effects of Caffeine Ingestion on Postural Balance, Functional Capacity and Cognitive Function in Patients with End Stage Renal Disease.

Patients with end stage renal disease (ESRD) display many cognitive and physiological alterations resulting from renal failure and physical inactivity. Caffeine intake has been reported to improve cognitive/physical performance in several studies. However, whether the benefits of caffeine intake apply to patients with ESRD remains unknown. The aim of the present study was to explore the effect of caffeine intake on postural balance, cognitive function and functional capacity in patients with ESRD. In a randomized order, 12 patients with ESRD (age: 33.85 ± 8.57 years; Female: 45.5%) performed a battery of tests after either caffeine (CF) (400 mg) or placebo (PLA) ingestion. Postural balance was evaluated using a stabilometric platform. Functional capacity was assessed with the sit-to-stand and up-and-go tests, and for cognitive performances, reaction time test and a vigilance test were used. Results showed a significant improvement in up-and-go test (p = 0.01) and sit-to-stand test performances with CF compared to PLA (p < 0.01). Time of reaction test and vigilance test (p < 0.01) performances were significantly higher with CF. No significant difference was observed in postural balance between CF and PLA. The results of this study suggest that acute caffeine ingestion positively enhances cognitive function and functional capacity in patients with ESRD.

Effects of Acute Ingestion of Guarana (Paullinia Cupana) on Soccer Player Performance: A Randomized, Cross-over, Placebo-Controlled Study

Objective To investigate the acute effects of ingesting a beverage containing guarana (Paullinia cupana) seed powder on performance during field tests related to physical capacities that are determinants of soccer performance, such as lower limb power, sprint, agility, and the capacity to carry out intermittent exercise. Methods The study was conducted using a randomized, crossover, and counterbalanced design, with a beverage containing guarana or placebo administered in a double-blind manner. Twenty-seven under-17 soccer players of a professional soccer club performed a battery of tests 60 min after the ingestion of guarana (3 g of the fruit seed powder) or placebo. Trials were performed with a 7-day washout period. The battery of tests included a countermovement jump test, sprints of 10 and 20 m, an Illinois agility test, and a Yo–Yo Intermittent Recovery Test level 1 (YYIR1). Results Guarana ingestion did not improve countermovement jump, sprints, or agility (p > 0.05). However, guarana ingestion increased the distance covered in the YYIR1, compared with placebo ingestion (p = 0.01). Conclusion Acute ingestion of guarana improves the capacity to perform intermittent exercise in soccer players but seems to be ineffective to improve lower limb power, sprint, and agility.

Effects of the low Fowler's sleep position and methazolamide treatment on sleep bruxism: A randomized controlled trial.

Intracranial pressure is one of the determinants of sympathetic activities, and sleep bruxism is associated with increased sympathetic activities. This study aimed to investigate effects of the low Fowler's sleep position and methazolamide treatment on the occurrence of rhythmic masticatory muscle activities/sleep bruxism episodes in patients with sleep bruxism in a randomized controlled trial. Polysomnographic recordings were performed on the patients with sleep bruxism sleeping in the low Fowler's (15°-30°) or supine position (n = 11), and with methazolamide or placebo treatment (100 mg, 3-4 hr before bedtime, P.O., n = 9), and changes in sleep variables and heart rate variance during sleep in the low Fowler's position or with methazolamide treatment were determined. Sleep bruxism index, number of masseter muscle electromyographic bursts per hour of sleep, ratio of rhythmic masticatory muscle activities/sleep bruxism duration to the total sleep duration, index of total limb movements, index of limb movements with rhythmic masticatory muscle activities, and number of sleep bruxism clusters per hour of sleep in the low Fowler's position and after methazolamide intake were significantly smaller (p < 0.05-0.001) than those in the supine position and after placebo intake, respectively. The low-frequency heart rate variance powers during non-rapid eye movement sleep stage 2 (N2) in the low Fowler's position and with methazolamide treatment were significantly lower (p < 0.05) than those during sleep in the supine position and with placebo treatment, respectively. In conclusion, sleep in the low Fowler's position and methazolamide treatment were associated with significant decreases in the occurrence of rhythmic masticatory muscle activities/sleep bruxism episodes, which might be due to a reduction in intracranial pressure and sympathetic activities mainly during non-rapid eye movement sleep stage 2.

Caffeine Attenuates Exacerbated Central Fatigue during Moderate-Intensity Cycling Exercise in Women with Fibromyalgia.

To compare the development of fatigability during a moderate-intensity cycling exercise between women with fibromyalgia (FM) and control women (CON) after acute ingestion of caffeine and placebo. Ten FM and 10 CON women performed a 30-min moderate-intensity cycling exercise 1 h after the ingestion of a capsule containing either caffeine or a placebo. Fatigability and its central and peripheral determinants were determined via changes from pre- to post-15 and post-30 min of exercise in maximal voluntary isometric contractions, voluntary activation (VA), and quadriceps potentiated twitch torque ( Qtw-pot ), respectively. Heart rate, muscle oxygen saturation, perceptive responses, mood state, localized and widespread pain, and sleepiness were also monitored during and after exercise. There was a time versus group interaction for maximal voluntary isometric contraction and VA ( P < 0.001) but not for Qtw-pot ( P = 0.363), indicating a greater rate of fatigability development, mainly caused by central mechanisms, in the FM than in the CON group. There was also a main effect of condition for VA ( P = 0.011), indicating that caffeine attenuates central mechanisms of fatigability in both groups. Caffeine ingestion also increased muscle oxygenation, perceived vigor, and energy, and decreased leg muscle pain, sleepiness, and perceived fatigue in both groups. However, caffeine improved perceived pleasure/displeasure and exercise adherence likelihood only in the FM group. Compared with CON, women with FM present a greater rate of fatigability during exercise, mainly of central origin. Caffeine seems to be a promising bioactive to counteract the central mechanisms of fatigability and improve the exercise experience among FM women.

Brown Fat: A Beta Way to Burn Calories, but Which Beta?

Brown fat is a thermogenic tissue that may have therapeutic value for the treatment of obesity and diabetes. That brown fat is under sympathetic control is indisputable, but considerable controversy exists as to which of the beta-adrenergic receptor subtypes, b1AR, b2AR or b3AR, is the primary regulator. The purpose of the current study was to determine if co-administration of the b3AR agonist, mirabegron, would increase energy expenditure and brown fat activation more than non-selective bAR stimulation (isoproterenol) alone. 14 healthy, active young adults (8 males, 6 females) participated in a randomized crossover study. Energy expenditure in a temperature-controlled room (22.1 deg C, 48.5% relative humidity) was determined at rest and after ingestion of placebo or mirabegron (100mg), prior to intravenous administration of isoproterenol (30 minutes at 6, 12, and 24 ng/kg fat free mass/min). Brown fat activity was estimated using supraclavicular skin temperature assessed via infrared thermography. Baseline energy expenditure was not different ( P=0.42) prior to placebo (1487±106 kcal/day; (mean±SE)) and mirabegron (1424±104 kcal/day). Non-selective bAR stimulation increased energy expenditure above baseline (11.6±5.5, 15.2±6.3 and 20.1±6.0%; P&lt;0.05); additional b3AR stimulation did not augment this response (18.0±3.8, 23.2±4.2 and 27.8±4.5%; P&gt;0.05). Baseline supraclavicular skin temperature was not different ( P=0.95) prior to placebo (35.004±0.967◦C) and mirabegron (34.992±0.967◦C). Only the greatest dose of non-selective bAR stimulation increased supraclavicular skin temperature above baseline (0.236±0.082◦C); additional b3AR stimulation did not augment this response (0.100±0.082◦C; P=0.09). Co-administration of a b3AR agonist did not increase energy expenditure and brown fat activation more than non-selective bAR stimulation alone. These preliminary data imply that the b3AR might not be the primary regulator of brown fat activation in humans. Offce of Naval Research N00014-21-1-2276. This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

Can the dietary inorganic nitrate supplementation mitigate the vascular dysfunction in elderly with Alzheimer’s disease?

Aging and Alzheimer disease (AD) are both characterized by progressive reduction in nitric oxide bioavailability and endothelial function impairment. Promising studies on young healthy individuals underly the positive effect of dietary nitrate supplementation on endothelial function. However, the pharmacokinetics of the plasma nitrate and nitrite (PN) and the accompanying endothelial responsiveness following the oral nitrate ingestion in healthy elderly (HE) and patients with AD is not clear. Our hypothesis was that due to the reduction of nitric oxide bioavailability during aging and AD, an equal dose of oral nitrate (ON) would ameliorate the endothelial responsiveness more in the HE and even more in patients with AD in comparison to healthy young subjects (HY). Therefore, with the aim of investigating the pharmacokinetics of PN and the time-course endothelial responsiveness in response to a single dose ON, 10 HY (25±4 YRS), 10 HE (72±8 YRS) and 13 AD (73±7 YRS) were recruited. PN levels and endothelial responsiveness (single-passive leg movement (ΔPLM)) were measured in the recruited individuals prior to (T0) and hourly for 4 hours (T1, T2, T3, and T4) after: a) a single dose of ON; and b) a single dose of placebo. As expected at T0 both PN and ΔPLM were significantly reduced in the HE and even more reduced in the AD in comparison to the HY (all p&lt;0.001). No changes in PN nor ΔPLM were detected in any group following placebo intake. PN increased significantly in all three groups at T1 (p&lt;0.001) and constantly increased up to T4, but no differences were detected between time points T1 to T4 in any group. ΔPLM increased significantly in all three groups at T2, reaching highest values at T4 (p&lt;0.001). However, AD exhibited significantly lower ΔPLM values at any time point compared to HY (p&lt;0.0001) and HE (p&lt;0.001). Significant correlation between PN and ΔPLM was found (p&lt;0.001, R2=0.1654). Contrary to our hypothesis, the results of this study suggest that the PN pharmacokinetics following a single dose of ON is similar in HY, HE and AD. Moreover, the expected time-course amelioration of the endothelial responsiveness was reduced in the HE and even more reduced in the AD, suggesting that other factors, rather than the nitric oxide bioavailability, are playing a role in the age- and AD-related vascular dysfunction. Ricerca di Base 2017 - RBVR17XRSA - Effectiveness of exercise and nitrate supplementation on progression of dementia in patients with Alzheimer’s disease. This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

Effectiveness of Partially Hydrolyzed Guar Gum on Cognitive Function and Sleep Efficiency in Healthy Elderly Subjects in a Randomized, Double-Blind, Placebo-Controlled, and Parallel-Group Study.

The consumption of functional foods in a daily diet is a promising approach for the maintenance of cognitive health. The present study examines the effects of water-soluble prebiotic dietary-fiber, partially hydrolyzed guar gum (PHGG), on cognitive function and mental health in healthy elderly individuals. Participants consumed either 5 g/day of PHGG or a placebo daily for 12 weeks in this randomized, double-blind, placebo-controlled, and parallel-group study. An assessment of cognitive functions, sleep quality, and subjective mood evaluations was performed at baseline and after 8 and 12 weeks of either PHGG or placebo intake. The visual memory scores in cognitive function tests and sleepiness on rising scores related to sleep quality were significantly improved in the PHGG group compared to the placebo group. No significant differences were observed in mood parameters between the groups. Vigor-activity scores were significantly improved, while the scores for Confusion-Bewilderment decreased significantly in the PHGG group when compared to the baseline. In summary, supplementation with PHGG was effective in improving cognitive functions, particularly visual memory, as well as enhancing sleep quality and vitality in healthy elderly individuals (UMIN000049070).

Investigating the effects of dopamine on short- and long-latency afferent inhibition.

Short- and long-latency afferent inhibition (SAI and LAI respectively) are phenomenon whereby the motor evoked potential induced by transcranial magnetic stimulation (TMS) is inhibited by a sensory afferent volley consequent to nerve stimulation. It remains unclear whether dopamine participates in the genesis or modulation of SAI and LAI. The present study aimed to determine if SAI and LAI are modulated by levodopa (l-DOPA). In this placebo-controlled, double-anonymized study Apo-Levocarb (100mg l-DOPA in combination with 25mg carbidopa) and a placebo were administered to 32 adult males (mean age 24±3 years) in two separate sessions. SAI and LAI were evoked by stimulating the median nerve and delivering single-pulse TMS over the motor hotspot corresponding to the first dorsal interosseous muscle of the right hand. SAI and LAI were quantified before and 1h following ingestion of drug or placebo corresponding to the peak plasma concentration of Apo-Levocarb. The results indicate that Apo-Levocarb increases SAI and does not significantly alter LAI. These findings support literature demonstrating increased SAI following exogenous dopamine administration in neurodegenerative disorders. KEY POINTS: Short- and long-latency afferent inhibition (SAI and LAI respectively) are measures of corticospinal excitability evoked using transcranial magnetic stimulation. SAI and LAI are reduced in conditions such as Parkinson's disease which suggests dopamine may be involved in the mechanism of afferent inhibition. 125mg of Apo-Levocarb (100mg dopamine) increases SAI but not LAI. This study increases our understanding of the pharmacological mechanism of SAI and LAI.

Baseline breast tissue characteristics determine the effect of tamoxifen on mammographic density change.

Tamoxifen prevents recurrence of breast cancer and is also approved for preventive, risk-reducing, therapy. Tamoxifen alters the breast tissue composition and decreases the mammographic density. We aimed to test if baseline breast tissue composition influences tamoxifen-associated density change. This biopsy-based study included 83 participants randomised to 6 months daily intake of placebo, 20, 10, 5, 2.5, or 1 mg tamoxifen. The study is nested within the double-blinded tamoxifen dose-determination trial Karolinska Mammography Project for Risk Prediction of Breast Cancer Intervention (KARISMA) Study. Ultrasound-guided core-needle breast biopsies were collected at baseline before starting treatment. Biopsies were quantified for epithelial, stromal, and adipose distributions, and epithelial and stromal expression of proliferation marker Ki67, oestrogen receptor (ER) and progesterone receptor (PR). Mammographic density was measured using STRATUS. We found that greater mammographic density at baseline was positively associated with stromal area and inversely associated with adipose area and stromal expression of ER. Premenopausal women had greater mammographic density and epithelial tissue, and expressed more epithelial Ki67, PR, and stromal PR, compared to postmenopausal women. In women treated with tamoxifen (1-20 mg), greater density decrease was associated with higher baseline density, epithelial Ki67, and stromal PR. Women who responded to tamoxifen with a density decrease had on average 17% higher baseline density and a 2.2-fold higher PR expression compared to non-responders. Our results indicate that features in the normal breast tissue before tamoxifen exposure influences the tamoxifen-associated density decrease, and that the age-associated difference in density change may be related to age-dependant differences in expression of Ki67 and PR.

Caffeine intervention after abstinence does not alter cognitive parameters in premenstrual syndrome women regardless of CYP1A2 genotype

This study aimed to evaluate the effect of caffeine on cognitive parameters in premenstrual syndrome women of childbearing age undergoing caffeine withdrawal, observing the influence of cytochrome P450 enzyme isozyme 1A2 genotypes. This is a crossover study with 26 women (all participants) grouped according to genotype (17 AA and 9 AC/CC). The cognitive assessment was carried out before and after caffeine or placebo. A significant increase in attention was showed both after placebo and caffeine administration, however, no statistical difference was observed between caffeine and placebo groups. This occurred both for all participants and in the genotype groups. Working memory was improved for all participants, and in the AC/CC group after placebo ingestion; the same did not occur after caffeine intake. In the AA group, no significant changes were observed for placebo or caffeine. Caffeine does not promote effects on cognitive performance in premenstrual syndrome women after caffeine abstinence.

Nocturnal Melatonin Ingestion Improves Soccer Players’ Short-Term Maximal Performances on the Following Day

ABSTRACT Purpose: Exogenous melatonin has been proven to have beneficial effects on sleep. A good sleep quality promotes recovery and improves physical performance. In this sense, the present study aimed to explore the potential effect of nocturnal melatonin ingestion on psycho-cognitive and short-term maximal performances, in the following morning. Method: Twelve professional soccer players (22.9 ± 1.3 years, 1.80 ± 0.05 m, and 72.0 ± 8.8 kg) volunteered to perform two separate testing sessions after either nocturnal melatonin or placebo ingestion. The next morning, participants performed the following psycho-cognitive and physical tests: Hooper’s index, reaction time, vigilance, handgrip strength (HG), squat jump (SJ), modified agility T-test (MAT) and Wingate anaerobic test (WanT). Rating of perceived exertion (RPE) and blood lactate [La] were recorded, respectively, immediately and 3 min after the WanT. Blood glucose [GL] was measured before and 3 min after WanT. Results: Compared with placebo, melatonin improved subjective sleep quality, short-term maximal performances (HG and SJ), reaction-time, as well as peak and mean WanT powers and decreased fatigue index and RPE scores. However, [La] and [GL] were not affected by melatonin ingestion. Conclusion: Nocturnal melatonin intake before sleep has beneficial effects on cognitive and physical performances the following day.

Belief That Caffeine Ingestion Improves Performance in a 6-Minute Time Trial Test without Affecting Pacing Strategy.

Thirteen recreationally trained males in long-distance running (age: 38.5 ± 11.9 years, 11.0 ± 8.8 years of running experience) performed a 6 min time trial test in each experimental condition (caffeine-informed/placebo ingested (placebo) and non-ingested (control)) separated by 7 days. The total distance covered was measured, and partial times of each 400 m were used to analyze the pacing strategy. Heart rate and kinematic variables were recorded for each split. In addition, the rate of perceived exertion and prevalence of caffeine side effects was measured using questionnaires. Placebo ingestion improved running performance in the 6 min time trial test (1668 ± 139 m placebo vs. 1642 ± 158 m control, t = 2.49; p = 0.03; moderate ES = 0.69), while pacing, heart rate, RPE, and kinematic variables were similar between conditions (p > 0.05 in all cases). Minor side effects were reported. Beliefs of caffeine ingestion can improve running performance at speeds around maximal aerobic speed in recreationally trained runners without affecting pacing strategy so this "nutritional" strategy could be useful in competition scenarios. As a practical application, recreationally trained runners could improve ≈5 s in 1500 m or mile competitions.

Effects of caffeine supplementation on anaerobic power and muscle activity in youth athletes

This study aimed to investigate the effects of caffeine ingestion on anaerobic performance and muscle activity in young athletes. In this randomized, double-blind, and placebo-controlled study, ten highly trained male post-puberal futsal players aged 15.9 ± 1.2 years conducted two laboratory sessions. Athletes performed the Wingate test 60 min after ingestion of caffeine (CAF, 6 mg/kg body mass) or placebo (PL, dextrose) (blinded administration). Peak power, mean power, and the fatigue index were assessed. During the performance of the Wingate test, electromyographic (EMG) data were recorded from selected lower limbs muscles to determine the root mean square (RMS), mean power frequency (MPF), and median power frequency (MDPF) as frequency domain parameters and wavelet (WT) as time-frequency domain parameters. Caffeine ingestion increased peak (0.80 ± 0.29 W/Kg; p = 0.01; d = 0.42) and mean power (0.39 ± 0.02 W/Kg; p = 0.01; d = 0.26) but did not significantly affect the fatigue index (52.51 ± 9.48%, PL: 49.27 ± 10.39%; p = 0.34). EMG data showed that the MPF and MDPF parameters decreased and the WT increased, but caffeine did not have a significant effect on these changes (p > 0.05). Moreover, caffeine ingestion did not significantly affect RMS changes in the selected muscles (p > 0.05). Here we showed that acute caffeine ingestion improved anaerobic performance without affecting EMG parameters in young male futsal athletes.

The effect of aquatic training and vitamin D3 supplementation on bone metabolism in postmenopausal obese women

Background/ObjectiveDespite prevalence of studies indicating the positive effect of land-based exercise on bone metabolism, there are limited findings regarding the effect of aquatic exercise. The present study aimed to evaluate the effects of aquatic training and vitamin D3 supplementation on femur bone mineral density (BMD), serum 25(OH)D, and parathyroid hormone (PTH) in postmenopausal obese women with vitamin D insufficiency. Methods40 postmenopausal obese women were randomly divided into four groups of aquatic training + vitamin D3 intake group; (ATD), aquatic training with placebo intake group (AT), vitamin D3 intake group (D), and control group with placebo intake (CON). AT groups performed aerobic aquatic exercises for 8 weeks. Vitamin D3 supplementation groups consumed oral dose of 4000 IU/d for 8 weeks. ResultsThe femur BMD was significantly higher in the ATD than the AT and D and CON groups; in AT it was higher than the D and CON groups. Serum 25(OH)D level in the ATD was more than AT and CON, and in the D was more than the CON and AT. PTH in the ATD group was lower compared to AT, D, and CON groups. PTH was lower in the AT and D compared to the CON. ConclusionIn postmenopausal obese women with vitamin D insufficiency or deficiency, combining vitamin D supplementation and aquatic training was the most effective method for improving bone metabolism; Vitamin D supplementation (alone) was not sufficient to affect some of bone metabolism indices; Aquatic training could not improve serum vitamin D. By priority, ATD, AT, and D indicated better bone related metabolism indices.

The Effect of Melatonin on Increasing the Health Related Quality of Life in Non-Metastatic Breast Cancer Patients: Three-Year Follow up a Clinical Trial.

Although breast cancer is common worldwide, if diagnosed early and treated on time, the probability of recovery is high and patients often experience a long life. Reducing the quality of life is a common side effect in patients. Melatonin may have an important role in fatigue, sleep disorders and, as a result, the health-related quality of life (HRQoL) in people. About 184 patients with breast cancer were enrolled in 2 groups: intervention with daily melatonin intake of 18 mg for 3 years (93 patients) and the control group with placebo intake (91 patients). Health-related quality of life and the effect of melatonin on increasing that were evaluated with the EORTC QLQ-C30 questionnaire, third edition at the beginning, 2 months later and 3 years after the beginning of the study. The general score of the HRQoL was significantly different both in the passage of time and in the comparative study of the 2 groups, and it was better in the melatonin group (P < .05). Long-term use of 18 mg of melatonin for 3 years in patients with non-metastatic breast cancer can lead to an increase in the patients' quality of life.