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1.
J Nutr Health Aging ; 26(9): 839-846, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36156675

RESUMO

OBJECTIVES: This study investigates whether a citrus and pomegranate complex (CPC) improves physical fitness, mental well-being, and blood biomarkers for oxidative stress and endothelial function in healthy elderly. DESIGN: A randomized placebo-controlled cross-over trial. PARTICIPANTS: The study included 36 healthy elderly aged 60-75 years old. INTERVENTION AND MEASUREMENTS: Participants received four weeks of CPC supplementation and performed the handgrip strength and senior fitness test. Quality of life (QOL) was assessed and blood samples were analyzed for oxidative stress and endothelial function markers. RESULTS: After four weeks of CPC supplementation, handgrip strength significantly improved (p=0.019), compared to placebo. Moreover, the thinking, memory, learning, and concentration facets were improved (p=0.042), compared to placebo, and plasma malondialdehyde decreased, compared to placebo (p=0.033). The intervention did not affect senior fitness and the other QOL domains and blood parameters. CONCLUSION: Four weeks of daily CPC supplementation significantly improves handgrip strength and self-evaluated measures of psychological function in healthy older adults. Further research should focus on mechanisms associated with physical performance.


Assuntos
Citrus , Punica granatum , Idoso , Biomarcadores , Suplementos Nutricionais , Método Duplo-Cego , Força da Mão , Humanos , Malondialdeído , Aptidão Física , Qualidade de Vida
2.
Scand J Med Sci Sports ; 25(5): e515-23, 2015 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-25438823

RESUMO

Running is a popular form of physical activity, despite of the high incidence of running-related injuries (RRIs). Because of methodological issues, the etiology of RRIs remains unclear. Therefore, the purposes of the study were to assess the incidence of RRIs and to identify risk factors for RRIs in a large group of novice runners. In total, 1696 runners of a 6-week supervised "Start to Run" program were included in the NLstart2run study. All participants were aged between 18 and 65, completed a baseline questionnaire that covered potential risk factors, and completed at least one running diary. RRIs were registered during the program with a weekly running log. An RRI was defined as a musculo-skeletal complaint of the lower extremity or back attributed to running and hampering running ability for three consecutive training sessions. During the running program, 10.9% of the runners sustained an RRI. The multivariable Cox regression analysis showed that a higher age, higher BMI, previous musculo-skeletal complaints not attributed to sports and no previous running experience were related to RRI. These findings indicate that many novice runners participating in a short-term running program suffer from RRIs. Therefore, the identified risk factors should be considered for screening and prevention purposes.


Assuntos
Corrida/lesões , Adulto , Fatores Etários , Índice de Massa Corporal , Feminino , Humanos , Incidência , Extremidade Inferior/lesões , Região Lombossacral/lesões , Masculino , Pessoa de Meia-Idade , Dor Musculoesquelética/epidemiologia , Países Baixos/epidemiologia , Estudos Prospectivos , Fatores de Risco , Corrida/estatística & dados numéricos
3.
Diabetologia ; 55(5): 1273-82, 2012 May.
Artigo em Inglês | MEDLINE | ID: mdl-22124605

RESUMO

AIMS/HYPOTHESIS: The present study compares the impact of endurance- vs resistance-type exercise on subsequent 24 h blood glucose homeostasis in individuals with impaired glucose tolerance (IGT) and type 2 diabetes. METHODS: Fifteen individuals with IGT, 15 type 2 diabetic patients treated with exogenous insulin (INS), and 15 type 2 diabetic patients treated with oral glucose-lowering medication (OGLM) participated in a randomised crossover experiment. Participants were studied on three occasions for 3 days under strict dietary standardisation, but otherwise free-living conditions. Blood glucose homeostasis was assessed by ambulatory continuous glucose monitoring over the 24 h period following a 45 min session of resistance-type exercise (75% one repetition maximum), endurance-type exercise (50% maximum workload capacity) or no exercise at all. RESULTS: Average 24 h blood glucose concentrations were reduced from 7.4 ± 0.2, 9.6 ± 0.5 and 9.2 ± 0.7 mmol/l during the control experiment to 6.9 ± 0.2, 8.6 ± 0.4 and 8.1 ± 0.5 mmol/l (resistance-type exercise) and 6.8 ± 0.2, 8.6 ± 0.5 and 8.5 ± 0.5 mmol/l (endurance-type exercise) over the 24 h period following a single bout of exercise in the IGT, OGLM and INS groups, respectively (p < 0.001 for both treatments). The prevalence of hyperglycaemia (blood glucose >10 mmol/l) was reduced by 35 ± 7 and 33 ± 11% over the 24 h period following a single session of resistance- and endurance-type exercise, respectively (p < 0.001 for both treatments). CONCLUSIONS/INTERPRETATION: A single session of resistance- or endurance-type exercise substantially reduces the prevalence of hyperglycaemia during the subsequent 24 h period in individuals with IGT, and in insulin-treated and non-insulin-treated type 2 diabetic patients. Both resistance- and endurance-type exercise can be integrated in exercise intervention programmes designed to improve glycaemic control. TRIAL REGISTRATION: Clinicaltrials.gov NCT00945165. FUNDING: The Netherlands Organization for Health Research and Development (ZonMw, the Netherlands).


Assuntos
Diabetes Mellitus Tipo 2/terapia , Terapia por Exercício/métodos , Hiperglicemia/terapia , Resistência Física/fisiologia , Treinamento Resistido , Idoso , Glicemia/análise , Glicemia/efeitos dos fármacos , Glicemia/fisiologia , Estudos Cross-Over , Diabetes Mellitus Tipo 2/sangue , Diabetes Mellitus Tipo 2/tratamento farmacológico , Feminino , Intolerância à Glucose/tratamento farmacológico , Intolerância à Glucose/terapia , Humanos , Hiperglicemia/fisiopatologia , Hipoglicemiantes/uso terapêutico , Insulina/uso terapêutico , Masculino , Pessoa de Meia-Idade
4.
Ned Tijdschr Geneeskd ; 152(33): 1839-43, 2008 Aug 16.
Artigo em Holandês | MEDLINE | ID: mdl-18783163

RESUMO

Two patients were diagnosed with exercise-related pain at the medial side of the lower leg. The first patient, an 18-year-old woman who had expanded her athletic activities extensively, had developed pain at the inner side of the distal third portion of the left lower leg. She showed over-pronation of the ankle during running. A 3-phase bone scintigram revealed diffuse uptake of the tracer covering a large portion of the medial tibia margin. Based on this evidence, a diagnosis of periostalgia was made. She recovered after a period of relative calf massages and used insoles. The second patient was a 28-year-old male endurance runner who developed pain at the medial shin after intensifying his training regimen. The periods without pain during running became increasingly shorter, and the medial side of the lower leg became sore and tense. Intracompartmental pressure measurements indicated exercise-related posterior deep compartment syndrome of the calf. The patient recovered after fasciotomy. In athletes, exercise-related symptoms of the medial side of the lower leg can be usually attributed to the tibial periosteum or tendons of the deep calfmusculature, tibial stress reaction or fracture, or a compartment syndrome of the deep calf. Surgery is indicated for chronic compartment syndrome, but conservative therapy provides favourable outcomes in the other types of disorders. The optimal conservative therapeutic approach is unknown, but it is advisable to temporary reduce symptom-provoking athletic activity and modify any risk factors present. Ankle over-pronation during running is considered a very relevant intrinsic risk factor.


Assuntos
Síndrome do Compartimento Anterior/fisiopatologia , Traumatismos em Atletas/etiologia , Traumatismos em Atletas/fisiopatologia , Dor/etiologia , Adolescente , Adulto , Traumatismos em Atletas/cirurgia , Traumatismos em Atletas/terapia , Fasciotomia , Feminino , Humanos , Perna (Membro) , Masculino , Músculos/fisiopatologia , Dor/fisiopatologia , Esforço Físico , Pressão , Fatores de Risco , Resultado do Tratamento
5.
Ned Tijdschr Geneeskd ; 152(33): 1844-8, 2008 Aug 16.
Artigo em Holandês | MEDLINE | ID: mdl-18783164

RESUMO

Doping is defined as an offence of the antidopingcode of the World Anti-Doping Agency (WADA). To uphold the code WADA has composed a list of prohibited substances and methods. The composition of the list is based on three mainstays: fair play, health risks and spirit of the sport. Among the prohibited substances are anabolic agents, erythropoietin, beta2-sympathicomimetics, growth hormone and masking agents. For some medications athletes may receive a therapeutic use exemption. Enforcement of the antidoping-code is performed by doping controls. For this purpose, blood and urine samples of athletes are collected and analysed. In 2006 approximately 200,000 samples were analysed worldwide, with 1.96% being tested positive. All physicians should be aware of the possibility that athletes use medication subjected to the doping regulations. There are guidelines for physicians on doping-related issues in medical practice.


Assuntos
Desempenho Atlético/normas , Dopagem Esportivo/legislação & jurisprudência , Dopagem Esportivo/prevenção & controle , Esportes/normas , Detecção do Abuso de Substâncias/métodos , Análise Química do Sangue , Comportamento Competitivo , Humanos , Papel do Médico , Urinálise
6.
Int J Sports Med ; 25(7): 533-8, 2004 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-15459835

RESUMO

Beta(2)-adrenergic agonists are important therapeutic agents for the prevention and treatment of (exercise-induced) asthma in athletes, but may have ergogenic effects. In this study we investigated whether inhalation of a supra-therapeutic dose of 800 microg salbutamol before exercise affects endurance performance during a cycling trial in non-asthmatic athletes. In a double-blind, randomized cross-over study, 16 athletes performed two trials, where they had to perform a certain amount of work as fast as possible on a cycle ergometer, 30 minutes after inhalation of 800 micro g salbutamol or placebo. Peak expiratory flow (PEF), forced vital capacity (FVC), and forced expiratory volume in 1 second (FEV(1)) were measured before and after exercise and blood samples were obtained before and during exercise. Cycling performance time was 4010.2 +/- 327.7 s after placebo inhalation and 3927.6 +/- 231.3 s after inhalation salbutamol (p < 0.05). Although salbutamol inhalation increased plasma free fatty acids, glycerol and lactate concentrations and decreased plasma potassium concentrations at rest, no differences between placebo and salbutamol in these variables were found during exercise. PEF and FEV(1) were increased after salbutamol inhalation at rest compared with placebo, but the difference between placebo and salbutamol after exercise was no longer significant. Inhalation of a supratherapeutic dose of 800 micro g salbutamol improved endurance cycling performance by 1.9 +/- 1.8 % in non-asthmatic athletes, which indicates that this route of administration does not exclude the possibility of an ergogenic effect of beta(2)-adrenergic agents in athletes. The increase in performance was not explained by changes in plasma concentrations of free fatty acids, glycerol, lactate, and potassium during exercise or by changes in ventilatory parameters at rest and after exercise. Therefore, the mechanism of the increase in performance remains to be determined.


Assuntos
Albuterol/farmacologia , Ciclismo/fisiologia , Broncodilatadores/farmacologia , Resistência Física/efeitos dos fármacos , Administração por Inalação , Adolescente , Adulto , Albuterol/administração & dosagem , Broncodilatadores/administração & dosagem , Estudos Cross-Over , Relação Dose-Resposta a Droga , Método Duplo-Cego , Ácidos Graxos/sangue , Glicerol/sangue , Humanos , Ácido Láctico/sangue , Masculino , Potássio/sangue , Testes de Função Respiratória
7.
Br J Sports Med ; 38(3): 253-9, 2004 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-15155420

RESUMO

OBJECTIVES: To investigate the effects of two different regimens of androgenic-anabolic steroid (AAS) administration on serum lipid and lipoproteins, and recovery of these variables after drug cessation, as indicators of the risk for cardiovascular disease in healthy male strength athletes. METHODS: In a non-blinded study (study 1) serum lipoproteins and lipids were assessed in 19 subjects who self administered AASs for eight or 14 weeks, and in 16 non-using volunteers. In a randomised double blind, placebo controlled design, the effects of intramuscular administration of nandrolone decanoate (200 mg/week) for eight weeks on the same variables in 16 bodybuilders were studied (study 2). Fasting serum concentrations of total cholesterol, triglycerides, HDL-cholesterol (HDL-C), HDL2-cholesterol (HDL2-C), HDL3-cholesterol (HDL3-C), apolipoprotein A1 (Apo-A1), apolipoprotein B (Apo-B), and lipoprotein (a) (Lp(a)) were determined. RESULTS: In study 1 AAS administration led to decreases in serum concentrations of HDL-C (from 1.08 (0.30) to 0.43 (0.22) mmol/l), HDL2-C (from 0.21 (0.18) to 0.05 (0.03) mmol/l), HDL3-C (from 0.87 (0.24) to 0.40 (0.20) mmol/l, and Apo-A1 (from 1.41 (0.27) to 0.71 (0.34) g/l), whereas Apo-B increased from 0.96 (0.13) to 1.32 (0.28) g/l. Serum Lp(a) declined from 189 (315) to 32 (63) U/l. Total cholesterol and triglycerides did not change significantly. Alterations after eight and 14 weeks of AAS administration were comparable. No changes occurred in the controls. Six weeks after AAS cessation, serum HDL-C, HDL2-C, Apo-A1, Apo-B, and Lp(a) had still not returned to baseline concentrations. Administration of AAS for 14 weeks was associated with slower recovery to pretreatment concentrations than administration for eight weeks. In study 2, nandrolone decanoate did not influence serum triglycerides, total cholesterol, HDL-C, HDL2-C, HDL3-C, Apo-A1, and Apo-B concentrations after four and eight weeks of intervention, nor six weeks after withdrawal. However, Lp(a) concentrations decreased significantly from 103 (68) to 65 (44) U/l in the nandrolone decanoate group, and in the placebo group a smaller reduction from 245 (245) to 201 (194) U/l was observed. Six weeks after the intervention period, Lp(a) concentrations had returned to baseline values in both groups. CONCLUSIONS: Self administration of several AASs simultaneously for eight or 14 weeks produces comparable profound unfavourable effects on lipids and lipoproteins, leading to an increased atherogenic lipid profile, despite a beneficial effect on Lp(a) concentration. The changes persist after AAS withdrawal, and normalisation depends on the duration of the drug abuse. Eight weeks of administration of nandrolone decanoate does not affect lipid and lipoprotein concentrations, although it may selectively reduce Lp(a) concentrations. The effect of this on atherogenesis remains to be established.


Assuntos
Anabolizantes/administração & dosagem , Androgênios/administração & dosagem , Apolipoproteínas/sangue , Doenças Cardiovasculares/sangue , Lipoproteína(a)/sangue , Nandrolona/análogos & derivados , Adulto , Apolipoproteína A-I/sangue , Apolipoproteínas B/sangue , Colesterol/sangue , HDL-Colesterol/sangue , Método Duplo-Cego , Exercício Físico , Humanos , Injeções Intramusculares , Masculino , Nandrolona/administração & dosagem , Decanoato de Nandrolona , Estudos Prospectivos , Autoadministração/métodos , Triglicerídeos/sangue
8.
Int J Sports Med ; 24(5): 344-51, 2003 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-12868045

RESUMO

Since the abuse of androgenic-anabolic steroids (AAS) has been associated with the occurrence of serious cardiovascular disease in young athletes, we performed two studies to investigate the effects of short-term AAS administration on heart structure and function in experienced male strength athletes, with special reference to dose and duration of drug abuse. In Study 1 the effects of AAS were assessed in 17 experienced male strength athletes (age 31 +/- 7 y) who self-administered AAS for 8 or 12 - 16 weeks and in 15 non-using strength athletes (age 33 +/- 5 y) in a non-blinded design. In Study 2 the effects of administration of nandrolone decanoate (200 mg/wk i. m.) for eight weeks were investigated in 16 bodybuilders in a randomised double blind, placebo controlled design. In all subjects M-mode and two-dimensional Doppler-echocardiography were performed at baseline and after 8 weeks AAS administration. In the athletes of Study 1 who used AAS for 12 - 16 weeks a third echocardiogram was also made at the end of the AAS administration period. Echocardiographic examinations included the determination of the aortic diameter (AD), left atrium diameter (LA), left ventricular end diastolic diameter (LVEDD), interventricular septum thickness (IVS), posterior wall end diastolic wall thickness (PWEDWT), left ventricular mass (LVM), left ventricular mass index (LVMI), ejection fraction (EF) and right ventricular diameter (RVD). For assessment of the diastolic function measurements of E and A peak velocities and calculation of E/A ratio were used. In addition, acceleration and deceleration times of the E-top (ATM and DT, respectively) were determined. For evaluation of factors associated with stroke volume the aorta peak flow (AV) and left ventricular ejection times (LVET) were determined. In Study 1 eight weeks AAS self-administration did not result in changes of blood pressure or cardiac size and function. Additionally, duration of AAS self-administration did not have any impact on these parameters. Study 2 revealed that eight weeks administration of nandrolone decanoate did not induce significant alterations in blood pressure and heart morphology and function. Short-term administration of AAS for periods up to 16 weeks did not lead to detectable echocardiographic alterations of heart morphology and systolic and diastolic function in experienced strength athletes. The administration regimen used nor the length of AAS abuse did influence the results. Moreover, it is concluded that echocardiographic evaluation may provide incomplete assessment of the actual cardiac condition in AAS users since it is not sensitive enough to detect alterations at the cellular level. Nevertheless, from the present study no conclusions can be drawn of the cardiotoxic effects of long term AAS abuse.


Assuntos
Anabolizantes/farmacologia , Coração/efeitos dos fármacos , Levantamento de Peso , Adulto , Análise de Variância , Estudos de Casos e Controles , Método Duplo-Cego , Ecocardiografia , Coração/anatomia & histologia , Coração/fisiologia , Humanos , Masculino , Estudos Prospectivos , Inquéritos e Questionários
9.
Int J Sports Med ; 23(6): 391-6, 2002 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-12215956

RESUMO

The purpose of this study was to monitor general and individual changes in hematological variables during long-term endurance training, detraining and altitude training in elite Olympic distance triathletes. Over a period of three years, a total of 102 blood samples were collected in eleven (7-male and 4 female) elite Olympic distance triathletes (mean +/- SD; age = 26.4 +/- 5.1 yr; VO(2) max = 67.9 +/- 6.6 ml/min/kg) for determination of hemoglobin (Hb), hematocrit (Hct), red blood cell count (RBC), Mean corpuscular hemoglobin (MCH), Mean corpuscular hemoglobin content (MCHC), Mean corpuscular volume (MCV) and plasma ferritin. The data were pooled and divided into three periods; off-season, training season and race season. Blood samples obtained before and after altitude training were analyzed separately. Of all measured variables only RBC showed a significant decrease (p < 0.05) during the race season compared to the training season. Hematological values below the lower limit of the normal range were found in 46 % of the athletes during the off-season. This percentage increased from 55 % during the training season to 72 % of the athletes during the race season. Hemoglobin and ferritin values were most frequently below the normal range. There was a weak correlation between Hb levels and VO(2) max obtained during maximal cycling (r = 0.084) and running (r = 0.137) tests. Unlike training at 1500 m and 1850 m, training at an altitude of 2600 m for three weeks showed significant increases in Hb (+ 10 %; p < 0.05), Hct (+ 11 %; p < 0.05) and MCV (+ 5 %; p < 0.05). Long-term endurance training does not largely alter hematological status. However, regular screening of hematological variables is desirable as many athletes have values near or below the lower limit of the normal range. The data obtained from altitude training suggest that a minimum altitude (>2000 m) is necessary to alter hematological status.


Assuntos
Índices de Eritrócitos , Educação Física e Treinamento , Resistência Física/fisiologia , Esportes/fisiologia , Adaptação Fisiológica , Adulto , Altitude , Ciclismo , Feminino , Seguimentos , Humanos , Masculino , Corrida , Esportes/normas
10.
Eur J Appl Physiol ; 86(3): 233-9, 2002 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-11990732

RESUMO

The objective of this investigation was to study the effects of androgenic-anabolic steroid (AAS) misuse on deltoid muscle fiber characteristics in experienced, male strength-trained athletes. In a double-blind study, 15 volunteers were administered nandrolone decanoate (ND) for 8 weeks (200 mg/week, intramuscularly). In an additional study, 12 subjects self-administered various AASs at supratherapeutic dosages (AAS group), while 7 non-users served as controls. In all subjects, a percutaneous needle biopsy sample of the deltoid muscle was obtained at baseline and after 8 weeks. Muscle sections were pre-incubated at pH 4.4, stained with adenosine triphosphatase and analyzed morphometrically. In each biopsy sample, at least 150 fibers were classified for "gray level" and "lesser fiber diameter" to determine the mean fiber size, the sizes of type I and type II fibers, and the fiber type distribution. ND administration did not seem to affect any of those parameters. In the AAS group, mean muscle fiber size (+ 12.6%), and the size of type I (+ 10.8%) and type II (+ 14.6%) muscle fibers increased. The fiber type distribution remained unaltered. We conclude that polydrug regimens of AAS misuse at supratherapeutic dosages increased the size of deltoid muscle fibers (especially type II fibers) in experienced strength-trained athletes, while ND at a therapeutic intramuscular dose of 200 mg did not exert any effect.


Assuntos
Anabolizantes/administração & dosagem , Músculo Esquelético/efeitos dos fármacos , Nandrolona/análogos & derivados , Nandrolona/administração & dosagem , Adulto , Biópsia , Dopagem Esportivo , Método Duplo-Cego , Exercício Físico/fisiologia , Humanos , Hipertrofia , Masculino , Fibras Musculares de Contração Rápida/citologia , Fibras Musculares de Contração Rápida/efeitos dos fármacos , Fibras Musculares de Contração Lenta/citologia , Fibras Musculares de Contração Lenta/efeitos dos fármacos , Músculo Esquelético/citologia , Músculo Esquelético/fisiologia , Decanoato de Nandrolona , Estudos Prospectivos
11.
Int J Sports Med ; 22(3): 235-41, 2001 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-11354529

RESUMO

The purpose of the present study was to investigate regional changes in body composition and anthropometric variables induced by nandrolone decanoate in bodybuilders. In a randomized, double blind, placebo controlled design 16 subjects received weekly intramuscular injections containing 200 mg nandrolone decanoate (ND) or placebo. Composition of total body and body parts were assessed using dual energy X-ray absorptiometry (DEXA), skinfolds and circumferences. Measurements were performed at baseline, after 8 weeks ND administration period and 6 weeks after drug withdrawal. DEXA revealed that total body mass (from 76.16 +/- 2.70 to 78.73 +/- 4.07 kg, p<0.5) and bone-free lean mass (from 59.54 +/- 2.36 to 63.06 +/- 2.99 kg, p < 0.025) increased significantly during ND administration whereas bone mineral mass remained unchanged. Six weeks after drug cessation bone-free lean mass was still increased compared to baseline levels. During ND administration significant increments of bone-free lean mass of the trunk (+ 2.03 kg) and legs (+ 1.08 kg) could be observed. Percentage fat of the legs decreased during the drug intervention period (-1.9%) and remained lowered six weeks after drug withdrawal. No alteration in any variable of the arms was observed. Skinfolds did not change during the entire study period in both groups. After 8 weeks ND administration circumference of the neck was increased (+0.9 cm) significantly although all circumferences underwent non-significant gains. In conclusion, the intramuscular administration of nandrolone decanoate (200 mg per week) during eight weeks induced an increase of body weight and bone-free lean body mass in bodybuilders that was mainly situated in the trunk and legs as determined by DEXA. The changes in the trunk were reflected in the circumferences but not the alterations in the legs. Skinfolds were not able to detect changes of fat mass of body parts. DEXA revealed that total fat mass and total percentage fat remained unaffected by drug administration while percentage fat of the legs decreased and remained lowered after drug cessation. These data indicate that changes of the composition of body parts induced by ND are elucidated less accurately by circumferences or skinfolds rather than by DEXA.


Assuntos
Anabolizantes/farmacologia , Antropometria , Composição Corporal/efeitos dos fármacos , Exercício Físico/fisiologia , Nandrolona/farmacologia , Levantamento de Peso/fisiologia , Absorciometria de Fóton , Adulto , Constituição Corporal , Índice de Massa Corporal , Método Duplo-Cego , Humanos , Masculino , Nandrolona/urina , Avaliação Nutricional , Dobras Cutâneas
12.
Phys Sportsmed ; 29(1): 49-65, 2001 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-20086552

RESUMO

UNLABELLED: Some strength athletes use androgenic-anabolic steroids (AAS) to improve body dimensions, though the drugs' long- and short-term effects have not been definitively established. OBJECTIVE: This study sought to investigate the short-and long-term effects of AAS self-administration on body dimensions and total and regional body composition. DESIGN: This prospective, unblinded study involved 35 experienced male strength athletes: 19 AAS users (drugs were self-administered) and 16 nonuser controls engaged in their usual training regimens. At baseline, 8 weeks, and 6 weeks after AAS withdrawal (for AAS users) circumferences were measured at 10 sites, and skinfolds measured at 8 sites. To assess differences in AAS regimens, 9 subjects took AAS for 8 weeks (short-AAS) and 10 athletes took AAS for 12 to 16 weeks (long-AAS). Body composition and anthropometry were assessed at baseline, at the end of AAS use, and 6 weeks later. Lean body mass (LBM) was calculated from body weight and percentage fat. Total and regional body composition was measured by dual-energy x-ray absorptiometry. RESULTS: AAS use increased users' body weight by 4.4 kg and LBM by 4.5 kg, and produced increases in several circumferences. Percentage of fat decreased (17.0% to 16.0%), but fat mass remained unchanged. Changes persisted 6 weeks after drug withdrawal but were not less than those taken at 8 weeks. Bone-free lean mass of all regional body parts increased in subjects taking AAS, but fat mass was unaffected. Short- and long-term AAS users did not differ in any parameter measured at 8 weeks or after drug withdrawal. CONCLUSION: In AAS users, 8 weeks of self-administered AAS increased body weight, lean body mass, and limb circumferences, but decreased percentage fat compared with controls. Changes remained 6 weeks after drug withdrawal, though for some measurements only partially. AAS stimulated the bone-free lean mass of all body parts, but it did not affect fat mass. Short-term and long-term AAS administration produced comparable effects.

13.
Med Sci Sports Exerc ; 32(7): 1300-6, 2000 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-10912897

RESUMO

PURPOSE: The ergogenic effect of acute beta2-adrenergic agonist administration in nonasthmatic individuals has not been clearly demonstrated. Therefore, the acute effects of oral administration of the beta2-adrenergic agonist salbutamol (4 mg) on muscle strength and endurance performance were studied in 16 nonasthmatic men in a double-blind randomized cross-over study. METHODS: Peak expiratory flow (Mini Wright Peakflowmeter), isokinetic strength of the knee extensors and knee flexors at four angular velocities (Cybex II dynamometer), and endurance performance in a cycle ergometer test until exhaustion at 70% of maximal workload were measured. RESULTS: Peak expiratory flow increased from 601 +/- 67 L x min(-1) to 629 +/- 64 L x min(-1) after salbutamol (P < 0.05). Peak torque was higher after salbutamol than after placebo (4.4% for the knee extensors, 4.9% for the knee flexors) (P < 0.05). Mean endurance time increased from 3,039 +/- 1,031 s after placebo to 3,439 +/- 1,287 s after salbutamol (P = 0.19). When four subjects complaining about adverse side effects were excluded from the analysis, the increase in endurance time (729 +/- 1,007 s or 29%) was statistically significant (P <-0.05). Salbutamol did not affect VO2, respiratory exchange ratio, heart rate, and plasma free fatty acid and glycerol concentration during exercise; plasma lactate and potassium concentrations were increased (P < 0.05). CONCLUSIONS: Under the conditions of this study, oral salbutamol appears to be an effective ergogenic aid in nonasthmatic individuals not experiencing adverse side effects.


Assuntos
Albuterol/farmacologia , Broncodilatadores/farmacologia , Contração Muscular/efeitos dos fármacos , Músculo Esquelético/efeitos dos fármacos , Resistência Física/efeitos dos fármacos , Administração Oral , Adulto , Albuterol/administração & dosagem , Broncodilatadores/administração & dosagem , Método Duplo-Cego , Ergometria , Frequência Cardíaca , Humanos , Ácido Láctico/análise , Masculino , Músculo Esquelético/fisiologia , Potássio/análise
14.
Int J Sports Med ; 19(8): 586-91, 1998 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-9877152

RESUMO

In order to study the relationship between physical fitness/sport-specific skills and sports injuries 136 physical education students were studied during their 4-years of training in a prospective investigation. Physical fitness was measured every year using a battery of fitness tests, and the performance marks of a number of sports scored at the exams of the academy were used as parameters for the sport-specific skills. Sports injuries were recorded every 3 weeks on standard forms. Relative risk ratios were calculated between the tertile groups good, average and poor for all variables of physical fitness and sport-specific skills. Injury-proneness was defined for all and for acute and chronic injuries separately near the median number of injuries sustained. In only 6 out of 126 computed relative risks was a significant difference found. Discriminant analysis revealed an explanation of 16%, 14% and 11% of the variance for respectively all, acute and chronic injuries, at which 5 or 6 variables in varying combination were included. From our findings it may be concluded that physical fitness and sport-specific skills have little impact on sports injuries for the following two main reasons. Firstly, subjects at risk for sports injuries participate per definition in sports activities and have consequently developed their fitness and skills compared to the sedentary population. Thus, the range in physical fitness or sports skills in the population at risk is relatively small (physical education students belong to the 7th-10th decile in fitness test scores within a general college student population) and therefore an effect is hard to show. Secondly, the total number of sports injuries is very small and moreover, it should be distributed over several categories for analysis. The favourable advantages of using physical education students to study intrinsic risk factors (comparable and varied sports program, excellent compliance) appeared to be insufficient to compensate for drawbacks of selection.


Assuntos
Traumatismos em Atletas/epidemiologia , Educação Física e Treinamento , Aptidão Física , Análise Discriminante , Feminino , Humanos , Masculino , Estudos Prospectivos , Fatores de Risco , Estudantes
15.
Ned Tijdschr Geneeskd ; 141(41): 1965-8, 1997 Oct 11.
Artigo em Holandês | MEDLINE | ID: mdl-9550746

RESUMO

In sports, medical drugs are applied for supposedly ergogenic effects. Forbidden drug use (doping) implies that the drug enhances performance, which is not always the case. Amphetamines are ergogenic particularly during short-term, explosive exercise. Amphetamines exert an ergolytic effect on high-intensity endurance exercise. Caffeine has an ergogenic effect on endurance performance in dosages of 3 to 6 mg/kg. Doping regulations allow a small amount of caffeine intake. Androgenic and anabolic steroids elicit an increase in muscle growth and strength. In females low doses appear to be ergogenic in all sport types. beta 2-adrenergic agonists appear to have a positive effect on strength and muscle growth. The effects on endurance performance are still unknown. Although growth hormone is used in sports, scientific studies show that compared with placebo no difference in strength and muscle volume is observed. Blood doping and administration of erythropoietin are effective in enhancing endurance performance.


Assuntos
Dopagem Esportivo , Agonistas Adrenérgicos beta/farmacologia , Anfetaminas/farmacologia , Anabolizantes/farmacologia , Androgênios/farmacologia , Cafeína/farmacologia , Estimulantes do Sistema Nervoso Central/farmacologia , Feminino , Hormônio do Crescimento Humano/farmacologia , Humanos , Masculino
16.
Int J Sports Med ; 17(6): 429-33, 1996 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-8884417

RESUMO

The purpose of this study was to investigate in a cross-sectional design body composition, muscle fiber characteristics, cardiovascular risk factors and liver enzymes in long-term androgenic-anabolic steroids (AAS) using bodybuilders three months after drug withdrawal (AAS group; n = 16) and in non-users (CO group; n = 12). Training and dietary data were collected in all subjects. Anthropometry included weight, height, 8 skinfolds and 11 circumferences. Percentage fat (%FAT), fat mass (FM) and lean body mass (LBM) were calculated. In a muscle biopsy from the vastus lateralis muscle water content, fiber type distribution and diameters of fiber type I and type II were determined. Age, height, training characteristics, nutrition, skinfolds, %FAT and FM did not differ between the groups. The AAS group had greater BW and LBM, and larger circumferences of thorax, waist, upper arm and thigh than the CO group. Muscle biopsy data were comparable, except for muscle fiber diameter of type I which was larger in the AAS group. No differences in serum values of total cholesterol, HDL-cholesterol and triglycerides, nor in systolic and diastolic blood pressure were observed. In both groups serum alkaline phosphatase and gamma GT were within the normal range. This study suggests that in long term AAS using body-builders, after a three months AAS free period, BW is greater than in non drug users. This is reflected in larger LBM, circumferences and diameter of muscle fiber type I. In addition, no differences in fat mass, blood pressure, lipoprotein profiles and liver enzymes exist between AAS users three months after interrupted drug use and their non drug using counterparts.


Assuntos
Anabolizantes , Composição Corporal , Dopagem Esportivo , Lipoproteínas/análise , Fígado/enzimologia , Transtornos Relacionados ao Uso de Substâncias/fisiopatologia , Levantamento de Peso/fisiologia , Adulto , Análise Química do Sangue , Pressão Sanguínea , Doenças Cardiovasculares/epidemiologia , Estudos Transversais , Humanos , Testes de Função Hepática , Masculino , Fibras Musculares Esqueléticas , Fatores de Risco
17.
Can J Appl Physiol ; 18(2): 189-96, 1993 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-8513291

RESUMO

The influence of strength training on muscle fiber area, capillary ultrastructure, and capillary supply was studied in experienced male bodybuilders taking either anabolic steroids or a placebo. During 8 weeks, 13 subjects received a weekly injection of either placebo or nandrolone decanoate (starting dose 200 mg, followed by 100 mg weekly), in a double-blind, counterbalanced design. Before and after 8 weeks a needle biopsy was taken from the vastus lateralis muscle for studying morphometric characteristics of fibers and ultrastructure and morphometric characteristics of capillaries. The fiber cross-sectional area increased significantly only after steroid treatment. Capillary ultrastructure and capillary supply were not changed after the training period. In none of the measured parameters was any difference found between placebo and steroid treatment.


Assuntos
Anabolizantes/farmacologia , Contração Muscular/fisiologia , Músculos/efeitos dos fármacos , Músculos/ultraestrutura , Nandrolona/análogos & derivados , Educação Física e Treinamento , Adulto , Anabolizantes/administração & dosagem , Membrana Basal/efeitos dos fármacos , Membrana Basal/ultraestrutura , Capilares/efeitos dos fármacos , Capilares/ultraestrutura , Método Duplo-Cego , Endotélio Vascular/efeitos dos fármacos , Endotélio Vascular/ultraestrutura , Humanos , Injeções Intramusculares , Masculino , Contração Muscular/efeitos dos fármacos , Músculos/irrigação sanguínea , Miofibrilas/efeitos dos fármacos , Miofibrilas/ultraestrutura , Nandrolona/administração & dosagem , Nandrolona/farmacologia , Decanoato de Nandrolona , Placebos
18.
Int J Sports Med ; 12(4): 413-8, 1991 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-1917227

RESUMO

The effects of anabolic steroids on body composition, blood pressure, lipid profile and liver functions were studied in male body builders who received a weekly i.m. injection of nandrolone-decanoate (100 mg) or placebo for 8 weeks in a double blind way. In addition, 5 body builders received the same dosage of nandrolone-decanoate or placebo, in a double blind cross-over design during two 8-week periods, interspersed by 12 weeks. Anabolic steroids induced a 25-27% decrease in HDL-cholesterol, which was virtually reversed 6 weeks after cessation of drug use. In the SAD group an increase in diastolic blood pressure was observed, which returned to pre-anabolic values approximately 6 weeks after cessation of drug administration. No deleterious effects of anabolic drugs on plasma activity of liver enzymes were found. Increases in lean body mass were found in all groups, though the increase in the subjects who received anabolic steroids was superior to that in the placebo-treated subjects. The increase in lean body mass suggests increases in muscle mass.


Assuntos
Anabolizantes/farmacologia , Pressão Sanguínea/efeitos dos fármacos , Composição Corporal/efeitos dos fármacos , Lipídeos/sangue , Fígado/fisiologia , Levantamento de Peso , Adulto , Anabolizantes/administração & dosagem , Método Duplo-Cego , Humanos , Fígado/efeitos dos fármacos , Fígado/enzimologia , Masculino , Nandrolona/administração & dosagem , Autoadministração
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