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1.
Pharmacol Res ; 156: 104764, 2020 06.
Article in English | MEDLINE | ID: mdl-32205233

ABSTRACT

In the sports domain, cannabis is prohibited by the World Anti-Doping Agency (WADA) across all sports in competition since 2004. The few studies on physical exercise and cannabis focused on the main compound i.e. Δ9-tetrahydrocannabinol. Cannabidiol (CBD) is another well-known phytocannabinoid present in dried or heated preparations of cannabis. Unlike Δ9-tetrahydrocannabinol, CBD is non-intoxicating but exhibits pharmacological properties that are interesting for medical use. The worldwide regulatory status of CBD is complex and this compound is still a controlled substance in many countries. Interestingly, however, the World Anti-Doping Agency removed CBD from the list of prohibited substances - in or out of competition - since 2018. This recent decision by the WADA leaves the door open for CBD use by athletes. In the present opinion article we wish to expose the different CBD properties discovered in preclinical studies that could be further tested in the sport domain to ascertain its utility. Preclinical studies suggest that CBD could be useful to athletes due to its anti-inflammatory, analgesic, anxiolytic, neuroprotective properties and its influence on the sleep-wake cycle. Unfortunately, almost no clinical data are available on CBD in the context of exercise, which makes its use in this context still premature.


Subject(s)
Cannabidiol/therapeutic use , Doping in Sports , Performance-Enhancing Substances/therapeutic use , Analgesics/therapeutic use , Animals , Anti-Anxiety Agents/therapeutic use , Anti-Inflammatory Agents/therapeutic use , Cannabidiol/adverse effects , Humans , Neuroprotective Agents/therapeutic use , Performance-Enhancing Substances/adverse effects , Sleep Aids, Pharmaceutical/therapeutic use
2.
Clin J Sport Med ; 30(1): 83-90, 2020 01.
Article in English | MEDLINE | ID: mdl-31855916

ABSTRACT

BACKGROUND: Actovegin is a biological drug with a controversial history of use in the treatment of sports injuries during the past 60 years. Particular concerns have been raised about its ergogenic potential to enhance performance, but some of these have been based on little more than anecdote. OBJECTIVES: In this article, we review the most recent scientific evidence to determine the clinical efficacy, safety profile, and legal status of Actovegin. METHODS: We considered all studies directly commenting on experience with Actovegin use as the primary intervention within the past 10 years. Outcomes included mechanisms of action, clinical efficacy in enhancing muscle repair, any report of safety issues, and any evidence for ergogenic effect. RESULTS: Our database search returned 212 articles, abstracts were screened, and after inclusion/exclusion criteria were applied, 25 articles were considered: Publications included 11 primary research articles (7 in vitro studies and 4 clinical trials), 8 review articles, 5 editorials, and a single case report. CONCLUSIONS: Current literature is still yet to define the active compound(s) of Actovegin, but suggests that it shows antioxidant and antiapoptotic properties, and may also upregulate macrophage responses central to muscle repair. Clinical efficacy was supported by one new original research article, and the use of Actovegin to treat muscle injuries remains safe and supported. Two articles argued the ergogenic effect of Actovegin, but in vitro findings did not to translate to the outcomes of a clinical trial. An adequate and meaningful scientific approach remains difficult in a field where there is immense pressure to deliver cutting-edge therapies.


Subject(s)
Antioxidants/therapeutic use , Athletic Injuries/drug therapy , Heme/analogs & derivatives , Muscle, Skeletal/injuries , Antioxidants/adverse effects , Antioxidants/pharmacology , Apoptosis/drug effects , Heme/adverse effects , Heme/pharmacology , Heme/therapeutic use , Humans , Macrophages/drug effects , Performance-Enhancing Substances/therapeutic use
3.
Subst Abus ; 41(1): 139-145, 2020.
Article in English | MEDLINE | ID: mdl-31545138

ABSTRACT

Background: Although people who inject performance- and image-enhancing drugs (PIEDs) report fewer unsafe injecting practices, stigma and discrimination may negatively impact their access to help and information. Engagement with health care services, compared with social networks (friends, relatives, and gym associates) and the Internet and media (steroid user forums, information sites, and magazines), may be important for harm minimization. Methods: A cross-sectional Internet or in-person survey of men who use PIEDs in Australia in 2014-2015 examined differences in sources for PIEDs, injecting equipment, and anabolic-androgenic steroids (AAS) information and factors associated with having periodical medical checks related to PIEDs issues using multivariate logistic regression. Results: In total, 267 men (mean age: 25 years, SD: 8.7 years; 246 of 267 [92%] reported recent AAS injection) were recruited. Most participants sourced injecting equipment from health professionals, PIEDs from their social networks, and AAS information from the Internet and media. Self-reported AAS knowledge was high and frequent. Higher income (adjusted odds ratio [AOR]: 2.04, 95% confidence interval [CI]: 1.03, 4.00), ≥2 different PIEDs used in addition to AAS (AOR: 1.94, 95% CI: 1.08, 3.49), and sourcing AAS information from health care professionals (AOR: 3.14, 95% CI: 1.81, 5.46) were independently associated with periodical medical checks. Participants nominated preference for improved health services through needle-syringe programs, primary care services, and peer educator support groups. Conclusion: Men who use PIEDs in Australia consider themselves well informed but tend to use Internet and media sources, providing potentially misleading or inaccurate information. Increasing trust between men who use PIEDs and health care providers may enable delivery of PIEDs-specific information to those at greatest need.


Subject(s)
Body Image , Patient Acceptance of Health Care , Performance-Enhancing Substances/therapeutic use , Substance Abuse, Intravenous/psychology , Testosterone Congeners , Adult , Australia , Cross-Sectional Studies , Harm Reduction , Humans , Male , Young Adult
4.
J Emerg Med ; 57(4): e105-e108, 2019 Oct.
Article in English | MEDLINE | ID: mdl-31493966

ABSTRACT

BACKGROUND: Clenbuterol is a long-acting ß-adrenergic agonist that is not Food and Drug Administration-approved for use in the United States, but may be obtained without a prescription from various unregulated sellers. It has seen increasing use as a performance-enhancing drug for sports. Literature on pediatric toxicity and treatment is limited. CASE REPORT: We report a case of a 2-year-old female presenting after an exploratory ingestion of clenbuterol. WHY SHOULD AN EMERGENCY PHYSICIAN BE AWARE OF THIS?: Use of performance-enhancing agents is increasing and physicians should be aware of the potential toxicity of intentional and unintentional ingestions of ß-adrenergic agonists. Patients may exhibit nausea, vomiting, tremor, tachycardia, and hypotension, along with laboratory abnormalities, including hyperglycemia, hypophosphatemia, hypokalemia, and hyperglycemia. Hypotension might not respond to adrenergic agents and may require administration of ß-adrenergic antagonists to maintain adequate perfusion.


Subject(s)
Clenbuterol/toxicity , Eating , Adrenergic beta-Agonists/therapeutic use , Adrenergic beta-Agonists/toxicity , Child, Preschool , Clenbuterol/therapeutic use , Female , Humans , Hypotension/etiology , Intensive Care Units, Pediatric/organization & administration , Performance-Enhancing Substances/therapeutic use , Performance-Enhancing Substances/toxicity , Tachycardia/etiology , Tremor/etiology , Vomiting/etiology
5.
J Strength Cond Res ; 33(7): 1929-1940, 2019 Jul.
Article in English | MEDLINE | ID: mdl-30789576

ABSTRACT

Boldt, P, Knechtle, B, Nikolaidis, P, Lechleitner, C, Wirnitzer, G, Leitzmann, C, and Wirnitzer, K. Sex differences in the health status of endurance runners: results from the NURMI study (step 2). J Strength Cond Res 33(7): 1929-1940, 2019-Optimized endurance performance is closely linked to a good health status (HS), which is crucially affected by sex. Therefore, the purpose of this study was to investigate sex differences in the HS of endurance runners of different distances. A total of 281 female and male recreational runners completed an online survey. Health status included body mass, smoking habits, felt stress, chronic diseases, allergies, intolerances, medication intake, supplement intake, health-related food choice, enhancement substance use, and health care utilization. Data analysis was performed using the independent t-test and chi-squared test with Cohen's d and Cramer's phi (φ) to evaluate the magnitude of the differences and associations. There were 159 female and 122 male participants, with 173 runners meeting the inclusion criteria, among them 103 half-marathoners, and 70 marathoners and ultramarathoners, of which one hundred eight 10-km runners were defined as the control group. Statistical significance (p < 0.05) was determined for the following findings: there was a higher prevalence of hypothyroidism in women; the use of thyroid medication and the intake of hormones and supplements prescribed by a doctor were more common in women; men reported more often a decrease in body mass due to running training, and women reported more often choosing food to obtain phytochemicals. There was no statistically significant association (p > 0.05) between sex and body mass change because of a change in diet, smoking habits, felt stress, chronic diseases except hypothyroidism, allergies, food intolerances, intake of antihypertensives and cholesterol-lowering medication, intake of performance-enhancing substances, or health care utilization. Both female and male runners had a good HS with no difference between sexes. Based on the findings of this study, monitoring thyroid parameters and vitamin D levels is required in female athletes, whereas adequate body mass control strategies are needed for their male counterparts.


Subject(s)
Health Status , Physical Endurance/physiology , Running/physiology , Sex Factors , Adult , Anticholesteremic Agents/therapeutic use , Antihypertensive Agents/therapeutic use , Chronic Disease , Diet , Dietary Supplements , Female , Hormones/therapeutic use , Humans , Hypersensitivity/epidemiology , Hypothyroidism/epidemiology , Male , Middle Aged , Nutritional Status , Performance-Enhancing Substances/therapeutic use , Smoking/epidemiology , Stress, Psychological/epidemiology , Surveys and Questionnaires , Vitamin D/blood , Weight Loss
6.
Eur J Nutr ; 57(3): 1181-1195, 2018 Apr.
Article in English | MEDLINE | ID: mdl-28285432

ABSTRACT

PURPOSE: The aim of the study was to investigate the effect of a 6-week, low-dose bovine colostrum (BC) supplementation on exercise-induced muscle damage (EIMD) and performance decline in soccer players following the Loughborough Intermittent Shuttle Test (LIST) during a competitive season period. METHODS: In a double-blind, randomized, placebo-controlled design, two groups of soccer players were allocated to a 3.2 g/day of whey protein (WP, N = 8) or BC (N = 10) and performed a pre- and a post-supplementation LIST. Maximum isometric voluntary contraction, squat jump (SQJ), countermovement jump, muscle soreness, blood cell counts, creatine kinase (CK), C-reactive protein (CRP) and interleukin-6 (IL-6) were monitored for 2, 24, 48, 72 h post-LIST. RESULTS: LIST induced transient increases in leukocytes, granulocytes, CK, muscle soreness, CRP, IL-6 and declines in lymphocytes and performance indices. Supplementation resulted in a faster recovery of SQJ, CK and CRP compared to pre-supplementation kinetics (trial × time: p = 0.001, 0.056, 0.014, respectively) and lower incremental area under the curve (iAUC) for IL-6, only in the BC group [pre-: 31.1 (6.78-46.9), post-: 14.0 (-0.16 to 23.5) pg h/ml, p = 0.034]. Direct comparison of the two groups after supplementation demonstrated higher iAUC of SQJ [WP: -195.2 (-229.0 to (-52.5)), BC: -15.8 (-93.2 to 16.8) cm h, p = 0.034], a trend for lower iAUC of CK in the BC group [WP: 18,785 (4651-41,357), BC: 8842 (4807-14,802) U h/L, p = 0.081] and a significant intervention × time interaction for CRP (p = 0.038) in favor of BC. CONCLUSIONS: Post-exercise EIMD may be reduced and performance better maintained by a low dose of BC administration following LIST in soccer players.


Subject(s)
Athletes , Colostrum , Dietary Supplements , Immunosuppressive Agents/therapeutic use , Myalgia/prevention & control , Performance-Enhancing Substances/therapeutic use , Sports Nutritional Physiological Phenomena , Adult , Animals , Athletic Performance , Biomarkers/blood , C-Reactive Protein/analysis , Cattle , Double-Blind Method , Exercise Test/adverse effects , Greece , Humans , Interleukin-6/blood , Muscle Fatigue , Myalgia/blood , Myalgia/etiology , Myalgia/immunology , Soccer , Whey Proteins/therapeutic use , Young Adult
7.
Eur J Nutr ; 56(2): 775-784, 2017 Mar.
Article in English | MEDLINE | ID: mdl-26658899

ABSTRACT

PURPOSE: Citrulline malate (CM) is a nonessential amino acid that increases exercise performance in males. However, based on physiological differences between genders, these results cannot be extrapolated to females. Therefore, the purpose of this investigation was to evaluate effects of acute CM supplementation on upper- and lower-body weightlifting performance in resistance-trained females. METHODS: Fifteen females (23 ± 3 years) completed two randomized, double-blind trials consuming either CM (8 g dextrose + 8 g CM) or a placebo (8 g dextrose). One hour after supplement consumption, participants performed six sets each of upper- (i.e., bench press) and lower-body (i.e., leg press) exercises to failure at 80 % of previously established one-repetition maximum. Immediately after each set, repetitions completed, heart rate and rating of perceived exertion (RPE) were recorded. RESULTS: Repeated-measures analysis of variance indicated that subjects completed significantly (p = .045) more repetitions throughout upper-body exercise when consuming CM versus placebo (34.1 ± 5.7 vs. 32.9 ± 6.0, respectively). When consuming CM, similar significant (p = .03) improvements in total repetitions completed were observed for lower-body exercise (66.7 ± 30.5 vs. 55.13 ± 20.64, respectively). Overall RPE score was significantly lower (p = .02) in upper-body exercise when subjects consumed CM versus placebo (7.9 ± 0.3 and 8.6 ± 0.2, respectively). The supplement consumed exhibited no significant effects on heart rate at any time point. CONCLUSIONS: Acute CM supplementation in females increased upper- and lower-body resistance exercise performance and decreased RPE during upper-body exercise. These data indicate that athletes competing in sports with muscular endurance-based requirements may potentially improve performance by acutely supplementing CM.


Subject(s)
Athletic Performance , Citrulline/analogs & derivatives , Dietary Supplements , Malates/administration & dosage , Muscle, Skeletal/physiology , Performance-Enhancing Substances/administration & dosage , Sports Nutritional Physiological Phenomena , Weight Lifting , Adult , Athletes , Citrulline/administration & dosage , Citrulline/adverse effects , Citrulline/therapeutic use , Cross-Over Studies , Dietary Supplements/adverse effects , Double-Blind Method , Fatigue/epidemiology , Fatigue/etiology , Fatigue/prevention & control , Female , Heart Rate , Humans , Malates/adverse effects , Malates/therapeutic use , Performance-Enhancing Substances/adverse effects , Performance-Enhancing Substances/therapeutic use , Physical Exertion , Prevalence , Resistance Training , United States/epidemiology , Young Adult
8.
Nutr Health ; 23(4): 239-249, 2017 Dec.
Article in English | MEDLINE | ID: mdl-29214927

ABSTRACT

BACKGROUND: Probiotics are live microorganisms that promote health benefits to the host. Evidence indicates that some probiotic strains play an immunomodulatory role and reduce the incidence of respiratory and gastrointestinal infections in athletes and in physical activity practitioners. For this reason, probiotic supplementation could indirectly improve exercise performance. However, recent studies have observed direct ergogenic effects of probiotics, but the mechanisms of action are poorly elucidated. OBJECTIVE: In this study, we aim to synthesize available knowledge on the effect of probiotics on physical exercise, identify the mechanisms of action by which probiotics could improve performance directly and indirectly, and verify whether probiotics have any ergogenic effect. METHODS: The study was performed in the PubMed database in February 2017, without limitation as to the publication period. The keyword combinations used were: 'Probiotics' and 'Sports' ( n = 17 articles), 'Probiotics' and 'Exercise' ( n = 26 articles) and 'Probiotics' and 'Athletes' ( n = 11 articles). RESULTS: Of the 16 studies evaluated, only six applied performance tests, of which only two demonstrated that probiotic supplementation increases performance, but one of them was performed with mice. CONCLUSIONS: According to the studies evaluated, probiotic supplementation does not present ergogenic effect, however, considering the small number of studies, this subject should be better investigated.


Subject(s)
Exercise , Fatigue/prevention & control , Performance-Enhancing Substances/therapeutic use , Probiotics/therapeutic use , Sports Nutritional Physiological Phenomena , Sports , Animals , Athletic Performance , Fatigue/etiology , Humans , Performance-Enhancing Substances/adverse effects , Probiotics/adverse effects , Reproducibility of Results
9.
Nutr Health ; 23(4): 231-238, 2017 Dec.
Article in English | MEDLINE | ID: mdl-29214920

ABSTRACT

BACKGROUND: Ergogenic effects of caffeine (CAF) ingestion have been observed in different cycling exercise modes, and have been associated with alterations in ratings of perceived exertion (RPE). However, there has been little investigation of maximal oxygen uptake (VO2MAX) test outcomes. AIM: This study aimed to verify whether CAF may reduce RPE, thereby improving maximal incremental test (MIT) outcomes such as VO2MAX, time to exhaustion and peak power output (WPEAK). METHODS: Nine healthy individuals performed three MITs (25 W/min until exhaustion) in a random, counterbalanced fashion after ingestion of CAF, placebo perceived as caffeine (PLA), and no supplementation (baseline control). VO2 was measured throughout the test, while RPE was rated according to overall and leg effort sensations. The power output corresponding to submaximal (RPE = 14 according to the 6-20 Borg scale) and maximal RPE was recorded for both overall (O-RPE14 and O-RPEMAX) and leg RPE (L-RPE14 and L-RPEMAX). RESULTS: VO2MAX did not change significantly between MITs; however, CAF and PLA increased time to exhaustion (↑ ∼18.7% and ∼17.1%, respectively; p < .05) and WPEAK (↑ ∼13.0% and ∼11.8%, respectively; p < .05) when compared with control. When compared with control, CAF ingestion reduced submaximal and maximal overall and leg RPEs, the effect being greater in maximal (likely beneficial in O-RPEMAX and L-RPEMAX) than submaximal RPE (possibly beneficial in O-RPE14 and L-RPE14). Similar results were found when participants ingested PLA. CONCLUSIONS: Compared with control, CAF and PLA improved MIT performance outcomes such as time to exhaustion and WPEAK, without altering VO2MAX values. CAF effects were attributed to placebo.


Subject(s)
Athletic Performance , Caffeine/therapeutic use , Dietary Supplements , Fatigue/prevention & control , Oxygen Consumption , Performance-Enhancing Substances/therapeutic use , Physical Exertion , Adult , Attitude to Health , Bicycling , Caffeine/adverse effects , Central Nervous System Stimulants/adverse effects , Central Nervous System Stimulants/therapeutic use , Deception , Dietary Supplements/adverse effects , Fatigue/etiology , Fatigue/physiopathology , Humans , Leg , Musculoskeletal Pain/etiology , Musculoskeletal Pain/prevention & control , Performance-Enhancing Substances/adverse effects , Reproducibility of Results , Severity of Illness Index , Single-Blind Method , Time Factors , Young Adult
10.
Nutr Health ; 23(4): 289-298, 2017 Dec.
Article in English | MEDLINE | ID: mdl-29214921

ABSTRACT

BACKGROUND: The constant pursuit of improved athletic performance characterizes high-performance sport and the use of medicinal plants as dietary supplements is becoming widespread among athletes to enhance long-term endurance performance. AIM: The present study evaluated the toxicity of Heteropterys tomentosa (HEHt) and its acute adaptogenic effects. METHODS: The in vitro safety profile was evaluated on CHO-k1 cells using the alamar Blue assay, at concentrations ranging from 3.125 to 200 µg/mL. In vivo acute oral toxicity was conducted in male and female mice with oral administration of graded doses of HEHt from 400 to 2000 mg/kg. A subchronic oral toxicity study was completed by oral administration of HEHt (50, 200 or 1000 mg/kg) and vehicle for 30 days in male Wistar rats. Clinical observations and toxicological related parameters were determined. Blood was collected for biochemical and hematological analyses, while histological examinations were performed on selected organs. Thereafter, an adaptogenic test consisting of progressive loads until exhaustion was conducted in rats ( n = 5/group) orally pre-treated with the vehicle and HEHt (25, 100 or 400 mg/kg). RESULTS: HEHt exhibited no cytotoxic effects on the CHO-k1 cells and, apparently, no acute toxicity in mice and no subchronic toxicity in rats. An ergogenic effect was observed only at the dose of 25 mg/kg compared with the vehicle in relation to time to exhaustion and exercise load ( p = .011 and .019, respectively). HEHt is safe at up to 400 mg/kg, contains astilbin and taxifolin as the major phytochemical compounds, and exhibited a potential adaptogenic effect. CONCLUSIONS: These results justify its anecdotal usage as a tonic, show that the hydroethanolic maceration of the root does not cause toxicity, and provide scientific evidence of its potential as a source of new adaptogenic substance(s).


Subject(s)
Dietary Supplements/adverse effects , Malpighiaceae/chemistry , Performance-Enhancing Substances/adverse effects , Plant Extracts/adverse effects , Plant Roots/chemistry , Animals , Behavior, Animal , CHO Cells , Cricetulus , Ethnopharmacology , Fatigue/etiology , Fatigue/prevention & control , Female , Flavonols/administration & dosage , Flavonols/adverse effects , Flavonols/metabolism , Flavonols/therapeutic use , Male , Malpighiaceae/growth & development , Medicine, Traditional , Mice , Performance-Enhancing Substances/administration & dosage , Performance-Enhancing Substances/metabolism , Performance-Enhancing Substances/therapeutic use , Physical Exertion , Plant Extracts/administration & dosage , Plant Extracts/metabolism , Plant Extracts/therapeutic use , Plant Roots/growth & development , Quercetin/administration & dosage , Quercetin/adverse effects , Quercetin/analogs & derivatives , Quercetin/metabolism , Quercetin/therapeutic use , Random Allocation , Rats, Wistar , Toxicity Tests, Acute , Toxicity Tests, Subchronic
11.
Article in German | MEDLINE | ID: mdl-28058459

ABSTRACT

The excessive sale of dietary supplements (DSs) has become a global multi-billion market as more and more people turn to DSs for a healthy lifestyle or for aesthetic reasons. DSs are also increasingly popular among athletes; 50-85% of recreational and 35-100% of competitive athletes report taking DSs, the latter more regularly. Unless pathological deficiencies are detected, the intake of DSs for recreational athletes is not recommended. While it may be advisable for competitive athletes to supplement their diet with certain macronutrients (proteins and carbohydrates), many micronutrients (vitamins, minerals) as well as allegedly performance enhancing DSs may only show minimal impact under specific conditions and for certain sports. However, most products lack proof of their effectiveness. In some cases, DSs may even have negative effects and reduce performance. Furthermore, competitive athletes should be aware of the fact that DSs may lead to positive doping tests, as they bear the risk of being contaminated with banned substances, or components may be banned substances themselves. Every single case of taking DSs should therefore be critically assessed and discussed with experts prior to use. DSs cannot replace a balanced diet and hard practice.


Subject(s)
Athletic Performance , Dietary Supplements/adverse effects , Doping in Sports/methods , Performance-Enhancing Substances/adverse effects , Performance-Enhancing Substances/therapeutic use , Evidence-Based Medicine , Humans
12.
Article in German | MEDLINE | ID: mdl-28058460

ABSTRACT

Synephrine is a sympathomimetic phenylethylamine derivative that occurs naturally in citrus fruits. It is often added to dietary supplements intended for weight loss and enhancement of sports performance, typically in the form of Citrus aurantium extracts and in many cases in combination with caffeine. The health risks of synephrine were evaluated on the basis of the available toxicological data and in accordance to the EFSA guidance on the safety assessment of botanicals and botanical preparations intended for use in food supplements. In animal studies, orally applied synephrine induced adrenergic effects on the cardiovascular system (increase of blood pressure, ventricular arrhythmias), which were enhanced by the concomitant application of caffeine as well as physical activity. Some human intervention studies investigating the acute effects of synephrine on blood pressure and heart rate of healthy, normotensive test persons indicate that synephrine can induce cardiovascular effects in humans. A series of published case reports of adverse cardiovascular effects (hypertension, cardiac arrhythmia, myocardial infarction) were associated with consumption of synephrine- and caffeine-containing dietary supplements. In conclusion, consumption of high amounts of synephrine, especially in combination with caffeine and physical exercise, is associated with an increased risk of adverse effects on the cardiovascular system. According to the assessment by the BfR (Bundesinstitut für Risikobewertung), daily intake of synephrine through dietary supplements should not exceed the median intake from conventional foods.


Subject(s)
Anti-Obesity Agents/adverse effects , Cardiovascular Diseases/etiology , Cardiovascular Diseases/prevention & control , Dietary Supplements/adverse effects , Performance-Enhancing Substances/adverse effects , Synephrine/adverse effects , Synephrine/therapeutic use , Anti-Obesity Agents/therapeutic use , Citrus/chemistry , Evidence-Based Medicine , Humans , Performance-Enhancing Substances/therapeutic use , Treatment Outcome
13.
Res Sports Med ; 25(1): 58-66, 2017.
Article in English | MEDLINE | ID: mdl-27934546

ABSTRACT

This study determined variability in time-to-peak pH after consumption of 300 mg kg-1 of sodium bicarbonate. Seventeen participants (mean ± SD: age 21.38 ± 1.5 years; mass 75.8 ± 5.8 kg; height 176.8 ± 7.6 cm) reported to the laboratory where a resting capillary sample was taken. Then, 300 mg kg-1 of NaHCO3 in 450 ml of flavoured water was ingested. Participants rested for 90 min and repeated blood samples were procured at 10 min intervals for 60 min and then every 5 min until 90 min. Blood pH concentrations were measured. Results suggested that time-to-peak pH (64.41 ± 18.78 min) was variable with a range of 10-85 min and a coefficient of variation of 29.16%. A bimodal distribution occurred, at 65 and 75 min. In conclusion, athletes, when using NaHCO3 as an ergogenic aid, should determine their time-to-peak pH to best utilize the added buffering capacity this substance allows.


Subject(s)
Acid-Base Equilibrium/drug effects , Acidosis/prevention & control , Athletic Performance/physiology , Performance-Enhancing Substances/pharmacology , Sodium Bicarbonate/pharmacology , Acid-Base Equilibrium/physiology , Acidosis/blood , Administration, Oral , Adult , Buffers , Humans , Hydrogen-Ion Concentration/drug effects , Male , Performance-Enhancing Substances/therapeutic use , Sodium Bicarbonate/therapeutic use
14.
Can J Physiol Pharmacol ; 94(5): 488-97, 2016 May.
Article in English | MEDLINE | ID: mdl-26871756

ABSTRACT

This study investigates the effect of the ergogenic supplement ß-hydroxy-ß-methylbutyrate (HMB) on insulin resistance induced by high-fructose diet (HFD) in rats. Male Sprague Dawley rats were fed 60% HFD for 12 weeks and HMB (320 mg·kg(-1)·day(-1), orally) for 4 weeks. HFD significantly increased fasting insulin, fasting glucose, glycosylated hemoglobin (HBA1C), liver glycogen content, and homeostasis model assessment of insulin resistance (HOMA-IR) index, while it decreased glucose and insulin tolerance. Furthermore, HFD significantly increased serum triglycerides (TG), low density lipoprotein cholesterol (LDL-C), and very low density lipoprotein cholesterol (VLDL-C) levels, while it significantly decreased high density lipoprotein cholesterol (HDL-C). Moreover, HFD significantly increased mRNA expression of glucose transporter type-2 (GLUT-2), the mammalian target of rapamycin (mTOR), and sterol regulatory element-binding protein-1c (SREBP-1c) but decreased peroxisome proliferator-activated receptor-alpha (PPAR-α) in liver. Aortic relaxation to acetylcholine (ACh) was impaired and histopathology showed severe hepatic steatosis. HMB significantly increased insulin tolerance and decreased fasting insulin, HOMA-IR, HBA1C, hepatic glycogen content, serum TG, LDL-C, and VLDL-C. Additionally, HMB enhanced ACh-induced relaxation, ameliorated hepatic steatosis, and decreased mRNA expression of GLUT-2. In conclusion, HMB may attenuate insulin resistance and hepatic steatosis through inhibiting GLUT-2 in liver.


Subject(s)
Dietary Supplements , Glucose Transporter Type 2/antagonists & inhibitors , Insulin Resistance , Liver/metabolism , Non-alcoholic Fatty Liver Disease/prevention & control , Performance-Enhancing Substances/therapeutic use , Valerates/therapeutic use , Animals , Dietary Carbohydrates/adverse effects , Endothelium, Vascular/physiopathology , Fructose/adverse effects , Gene Expression Regulation , Glucose Intolerance/metabolism , Glucose Intolerance/pathology , Glucose Intolerance/physiopathology , Glucose Intolerance/prevention & control , Glucose Transporter Type 2/genetics , Glucose Transporter Type 2/metabolism , Hyperinsulinism/metabolism , Hyperinsulinism/pathology , Hyperinsulinism/physiopathology , Hyperinsulinism/prevention & control , Hyperlipidemias/metabolism , Hyperlipidemias/pathology , Hyperlipidemias/physiopathology , Hyperlipidemias/prevention & control , Liver/pathology , Male , Non-alcoholic Fatty Liver Disease/metabolism , Non-alcoholic Fatty Liver Disease/pathology , Non-alcoholic Fatty Liver Disease/physiopathology , PPAR alpha/metabolism , Random Allocation , Rats, Sprague-Dawley , Sterol Regulatory Element Binding Protein 1/metabolism , TOR Serine-Threonine Kinases/metabolism , Vascular Resistance
15.
Appetite ; 105: 156-63, 2016 10 01.
Article in English | MEDLINE | ID: mdl-27215836

ABSTRACT

OBJECTIVE: Caffeine has been shown to have effects on certain areas of cognition, but in executive functioning the research is limited and also inconsistent. One reason could be the need for a more sensitive measure to detect the effects of caffeine on executive function. This study used a new non-immersive virtual reality assessment of executive functions known as JEF(©) (the Jansari Assessment of Executive Function) alongside the 'classic' Stroop Colour-Word task to assess the effects of a normal dose of caffeinated coffee on executive function. METHOD: Using a double-blind, counterbalanced within participants procedure 43 participants were administered either a caffeinated or decaffeinated coffee and completed the 'JEF(©)' and Stroop tasks, as well as a subjective mood scale and blood pressure pre- and post condition on two separate occasions a week apart. JEF(©) yields measures for eight separate aspects of executive functions, in addition to a total average score. RESULTS: Findings indicate that performance was significantly improved on the planning, creative thinking, event-, time- and action-based prospective memory, as well as total JEF(©) score following caffeinated coffee relative to the decaffeinated coffee. The caffeinated beverage significantly decreased reaction times on the Stroop task, but there was no effect on Stroop interference. CONCLUSION: The results provide further support for the effects of a caffeinated beverage on cognitive functioning. In particular, it has demonstrated the ability of JEF(©) to detect the effects of caffeine across a number of executive functioning constructs, which weren't shown in the Stroop task, suggesting executive functioning improvements as a result of a 'typical' dose of caffeine may only be detected by the use of more real-world, ecologically valid tasks.


Subject(s)
Caffeine/therapeutic use , Central Nervous System Stimulants/therapeutic use , Coffee , Executive Function , Mental Fatigue/diagnosis , Mental Fatigue/prevention & control , Performance-Enhancing Substances/therapeutic use , Adult , Caffeine/adverse effects , Central Nervous System Stimulants/adverse effects , Coffee/adverse effects , Double-Blind Method , Female , Humans , Hypertension/etiology , Male , Mental Fatigue/diet therapy , Mood Disorders/etiology , Performance-Enhancing Substances/adverse effects , Psychiatric Status Rating Scales , Task Performance and Analysis , Virtual Reality
16.
Nutr Neurosci ; 18(2): 76-86, 2015 Feb.
Article in English | MEDLINE | ID: mdl-24621069

ABSTRACT

OBJECTIVE: Certain plant polysaccharides may provide psychological health benefits. The aim of this study was to evaluate whether they can acutely improve mood and cognitive function. METHOD: In a randomized, double-blind, placebo-controlled, between subjects design trial, 73 middle-aged adults consumed 4 g of a proprietary mixture of non-starch polysaccharides (NSPs) (Ambrotose® complex), a rice flour placebo, or a sucrose control. Participants completed testing at baseline and 30 minutes post-consumption. Acute effects of consumption on mood, cognition, and blood glucose were evaluated during mental tests designed to induce mental fatigue. RESULTS: Significant improvement in recognition and working memory performance was observed in the group that consumed NSP compared with placebo or sucrose. Improvements in memory performance following NSP intake were independent of changes in blood glucose. DISCUSSION: This is the first report of acute behavioural improvement following plant polysaccharide intake in healthy middle-aged adults under conditions of mental fatigue. The findings suggest that certain NSP may enhance memory performance through mechanisms other than elevated blood glucose.


Subject(s)
Aging , Cognitive Dysfunction/prevention & control , Dietary Supplements , Nootropic Agents/therapeutic use , Polysaccharides/therapeutic use , Cohort Studies , Double-Blind Method , Female , Galactans/therapeutic use , Galactose/analogs & derivatives , Glucosamine/therapeutic use , Humans , Male , Mannans/therapeutic use , Memory, Short-Term , Mental Fatigue/prevention & control , Middle Aged , Performance-Enhancing Substances/therapeutic use , Recognition, Psychology
17.
Int J Sport Nutr Exerc Metab ; 25(4): 367-74, 2015 Aug.
Article in English | MEDLINE | ID: mdl-25811286

ABSTRACT

Blackcurrant contains anthocyanins, known to influence vasorelaxation and peripheral blood flow. We examined the effects of 7 days intake of Sujon New Zealand blackcurrant powder (6g/day) on the lactate curve, maximum oxygen uptake, and cardiovascular responses at rest and during cycling. Thirteen trained triathletes with >3 yrs experience (8 men, age: 38 ± 8 yrs, body mass: 71 ± 9 kg, BF%: 19 ± 5%, mean ± SD) performed two incremental cycling protocols with recording of physiological and cardiovascular responses (Portapres Model 2). Cardiovascular function was also measured in rest. Experimental design was double-blind, placebo-controlled, randomized and cross-over (wash-out 4 wks). Data were analyzed with two-tailed t tests and 2-way ANOVA and significance accepted at p < .05. Plasma lactate was lower at 40%, 50%, 60% and 70% of maximum power by 27%, 22%, 17% and 13%. Intensity at 4 mmol · La(-1) OBLA was 6% higher with blackcurrant without effect on heart rate and oxygen uptake. Maximum values of oxygen uptake, heart rate and power were not affected by blackcurrant, but obtained with 14% lower lactate. In rest, blackcurrant increased stroke volume and cardiac output by 25% and 26%, and decreased total peripheral resistance by 16%, with no changes in blood pressure and heart rate. Cardiovascular responses during exercise at 40%, 50%, 60%, 70% and 80% intensity were not affected. Sujon New Zealand blackcurrant powder affects lactate production and/or clearance during exercise. Sujon New Zealand blackcurrant powder affects physiological and cardiovascular responses in rest and during exercise that may have implications for exercise performance.


Subject(s)
Antioxidants/therapeutic use , Dietary Supplements , Fatigue/prevention & control , Fruit/chemistry , Physical Endurance , Ribes/chemistry , Sports Nutritional Physiological Phenomena , Adult , Athletic Performance , Bicycling , Cross-Over Studies , Double-Blind Method , England , Fatigue/blood , Fatigue/metabolism , Female , Fruit/growth & development , Humans , Lactic Acid/blood , Lactic Acid/metabolism , Male , Middle Aged , New Zealand , Performance-Enhancing Substances/therapeutic use , Ribes/growth & development , Vascular Resistance , Vasodilator Agents/therapeutic use
18.
Int J Sport Nutr Exerc Metab ; 25(4): 359-66, 2015 Aug.
Article in English | MEDLINE | ID: mdl-25811674

ABSTRACT

Beetroot juice (BR) has been shown to lower the oxygen cost of exercise in normoxia and may have similar effects in hypoxia. We investigated the effect of BR on steady-state exercise economy and 10-km time trial (TT) performance in normoxia and moderate hypoxia (simulated altitude: ~2500 m). Eleven trained male cyclists (VO 2peak ≥ 60 ml · kg(-1) · min(-1)) completed four exercise trials. Two hours before exercise, subjects consumed 70 mL BR (~6 mmol nitrate) or placebo (nitrate-depleted BR) in a randomized, double-blind manner. Subjects then completed a 15-min self-selected cycling warm-up, a 15-min steady-state exercise bout at 50% maximum power output, and a 10-km time trial (TT) in either normoxia or hypoxia. Environmental conditions were randomized and single-blind. BR supplementation increased plasma nitrate concentration and fraction of exhaled nitric oxide relative to PL (p < .05 for both comparisons). Economy at 50% power output was similar in hypoxic and normoxic conditions (p > .05), but mean power output was greater in the normoxic TT relative to the hypoxic TT (p < .05). BR did not affect economy, steady-state SpO2, mean power output, or 10-km TT completion time relative to placebo in either normoxia or hypoxia (p > .05 in all comparisons). In conclusion, BR did not lower the oxygen cost of steady-state exercise or improve exercise performance in normoxia or hypoxia in a small sample of well-trained male cyclists.


Subject(s)
Athletic Performance , Beta vulgaris/chemistry , Fatigue/prevention & control , Fruit and Vegetable Juices , Oxygen Consumption , Plant Roots/chemistry , Sports Nutritional Physiological Phenomena , Adult , Bicycling , Breath Tests , British Columbia , Cross-Over Studies , Double-Blind Method , Fatigue/blood , Fatigue/etiology , Fatigue/metabolism , Fruit and Vegetable Juices/analysis , Humans , Hypoxia/physiopathology , Male , Nitrates/blood , Nitrates/metabolism , Nitrates/therapeutic use , Nitric Oxide/analysis , Nitric Oxide/metabolism , Performance-Enhancing Substances/therapeutic use , Severity of Illness Index , Single-Blind Method
19.
J Strength Cond Res ; 29(10): 2980-95, 2015 Oct.
Article in English | MEDLINE | ID: mdl-26200194

ABSTRACT

Ginger is a popular spice used to treat a variety of maladies, including pain. Nonsteroidal anti-inflammatory drugs (NSAIDs) are frequently used by athletes to manage and prevent pain; unfortunately, NSAIDs contribute to substantial adverse effects, including gastrointestinal (GI) dysfunction, exercise-induced bronchoconstriction, hyponatremia, impairment of connective tissue remodeling, endurance competition withdrawal, and cardiovascular disease. Ginger, however, may act as a promoter of GI integrity and as a bronchodilator. Given these potentially positive effects of ginger, a systematic review of randomized trials was performed to assess the evidence for ginger as an analgesic and ergogenic aid for exercise training and sport. Among 7 studies examining ginger as an analgesic, the evidence indicates that roughly 2 g·d(-1) of ginger may modestly reduce muscle pain stemming from eccentric resistance exercise and prolonged running, particularly if taken for a minimum of 5 days. Among 9 studies examining ginger as an ergogenic aid, no discernable effects on body composition, metabolic rate, oxygen consumption, isometric force generation, or perceived exertion were observed. Limited data suggest that ginger may accelerate recovery of maximal strength after eccentric resistance exercise and reduce the inflammatory response to cardiorespiratory exercise. Major limitations to the research include the use of untrained individuals, insufficient reporting on adverse events, and no direct comparisons with NSAID ingestion. While ginger taken over 1-2 weeks may reduce pain from eccentric resistance exercise and prolonged running, more research is needed to evaluate its safety and efficacy as an analgesic for a wide range of athletic endeavors.


Subject(s)
Analgesics/therapeutic use , Performance-Enhancing Substances/therapeutic use , Phytotherapy , Zingiber officinale , Humans , Myalgia/therapy , Sports Medicine
20.
Scand J Med Sci Sports ; 24(5): e398-405, 2014 Oct.
Article in English | MEDLINE | ID: mdl-25371934

ABSTRACT

To enable preventive measures to be designed, it is important to identify modifiable distal and proximal factors underlying doping behavior. This study investigated aspects of the prototype willingness model in relation to doping. A cross-sectional study was conducted involving 729 competitive athletes. Following ethical approval, athletes (mean age = 28.8 ± 10.1 years; 63% male) completed an online questionnaire, which assessed doping-related attitudes, norms, prototype perceptions, outcome expectancies, and behavioral willingness. Using hierarchical multiple regression analysis, 54.4% of the total variance in willingness to dope was explained. Specifically, past doping, attitudes, and favorability of performance enhancing substance user prototypes were the strongest unique predictors of willingness to dope. Athletes appeared most willing to dope if they were to suffer an injury, a dip in performance, or think others are doping and getting away with it. National-level athletes displayed significantly greater willingness to dope (Kruskal-Wallis γ2 = 35.9, P < 0.001) and perceived themselves as significantly more similar to a doper (Kruskal-Wallis γ2 = 13.4, P = 0.004) than athletes competing at any other level. The findings highlight the importance of extending anti-doping provision beyond elite-level sport and the need to target athletes' doping-related perceptions.


Subject(s)
Athletes/psychology , Doping in Sports/prevention & control , Doping in Sports/psychology , Models, Psychological , Adolescent , Adult , Attitude , Female , Health Knowledge, Attitudes, Practice , Humans , Male , Perception , Performance-Enhancing Substances/therapeutic use , Social Norms , Surveys and Questionnaires , Young Adult
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