Ingestion of a moderate dose of alcohol enhances physical exercise-induced changes in blood lactate concentration

The consumption of alcoholic beverages influences carbohydrate and lipid metabolism, although it is not yet clear whether metabolism during physical exercise at different intensities is also affected. This was the objective of the present study. Eight young and healthy volunteers performed a treadmill test to identify the running speed corresponding to a lactate concentration of 4 mM (S4mM). At least 48 h later, they were subjected to two experimental trials (non-alcohol or alcohol) in which they performed two 1-km running sessions at the following intensities: 1) S4mM; 2) 15% above S4mM. In both trials, blood lactate, triglycerides, and glucose concentrations were measured before and after exercise. The acute alcohol intake increased triglycerides, but not lactate concentration under resting conditions. Interestingly, alcohol intake enhanced the exercise-induced increase in lactate concentration at the two intensities: S4mM (non-alcohol: 4.2±0.3 mM vs alcohol: 4.8±0.9 mM; P=0.003) and 15% above S4mM trial (P=0.004). When volunteers ingested alcohol, triglycerides concentration remained increased after treadmill running (e.g., at S4mM - at rest; non-alcohol: 0.2±0.5 mM vs alcohol: 1.3±1.3 mM; P=0.048). In contrast, glucose concentration was not modified by either alcohol intake, exercise, or their combination. We concluded that an acute alcohol intake changed lactate and lipid metabolism without affecting blood glucose concentration. In addition, the increase in lactate concentration caused by alcohol was specifically observed when individuals exercised, whereas augmented triglycerides concentration was already observed before exercise and was sustained thereafter.

Uso de Esteroides Anabólicos en Jóvenes de Asunción / Anabolic Steroid Use in Young People of Asuncion

Los esteroides anabólicos típicamente usados por jóvenes, atletas y culturistas para incrementar el musculo y la fuerza son peligrosos, están accesibles, y se prescriben de manera errónea como eficaces, pero con riesgo bajo. No solo los atletas consumen esteroides anabólicos. Algunos jóvenes los toman para lucir más musculosos o para quemar grasa. El objetivo del estudio fue identificar los factores asociados al uso de anabólicos esteroides en jóvenes de 16 a 25 años que asisten al Gimnasio Fitness Family Caff de Asunción, conocer los datos socio-demográficos, caracterizar los conocimientos y el uso de esteroides anabólicos en el gimnasio y determinar el factor de consumo de esteroides anabólicos de acuerdo a la práctica en el gimnasio. Estudio tipo observacional descriptivo de corte transversal que contó con la participación de 41 jóvenes provenientes en su mayoría de Asunción. En cuanto a los factores se determinó que su uso está motivado por mejorar el aspecto físico, es decir, por un factor estético al igual que por la participación en competencias fitness

Anabolic steroids, typically used by young people, athletes and bodybuilders to increase muscle and strength, are dangerous, accessible and are prescribed incorrectly as effective, but with low risk. Not only athletes consume anabolic steroids. Some young people take them to look more muscular or for fat burning. The study had the following objectives: To identify factors associated with the use of anabolic steroids in 16 to 25 years young people who attend the Family Fitness Caff Gym in Asuncion, to know the socio-demographic data, characterize the knowledge and use of anabolic steroids in the gym, and determine the consumption factor of anabolic steroids according to the practice in the gym. This was an observational descriptive cross-sectional study. The study had the participation of 41 young people, mostly from Asuncion. In relation to the factors, it was determined that their use was motivated to improve their physical appearance; this is to say, for an aesthetic factor as well as for the participation in fitness competitions.

Intraoperative Neural Response Telemetry and Neural Recovery Function: a Comparative Study between Adults and Children

Introduction Neural response telemetry (NRT) is a method of capturing the action potential of the distal portion of the auditory nerve in cochlear implant (CI) users, using the CI itself to elicit and record the answers. In addition, it can alsomeasure the recovery function of the auditory nerve (REC), that is, the refractory properties of the nerve. It is not clear in the literature whether the responses from adults are the same as those from children. Objective To compare the results of NRT and REC between adults and children undergoing CI surgery. Methods Cross-sectional, descriptive, and retrospective study of the results of NRT and REC for patients undergoing IC at our service. The NRT is assessed by the level of amplitude (microvolts) and REC as a function of three parameters: A (saturation level, in microvolts), t0 (absolute refractory period, in seconds), and tau (curve of the model function), measured in three electrodes (apical, medial, and basal). Results Fifty-two patients were evaluated with intraoperative NRT (26 adults and 26 children), and 24 with REC (12 adults and 12 children). No statistically significant difference was found between intraoperative responses of adults and children for NRTor for REC's three parameters, except for parameter A of the basal electrode. Conclusion The results of intraoperative NRT and REC were not different between adults and children, except for parameter A of the basal electrode. .

Effects of acute supplementation of Panax ginseng on endurance running in a hot & humid environment.

Background & objectives: Athletes in Malaysia need to perform in a hot and humid environment due to the climatic nature of the country. c0 hronic supplementation of Panax ginseng (PG) (a deciduous perennial plant belonging to the Araliaceae family) enhances physical performance. As the ergogenic effect of acute supplementation of PG on endurance performance has not been explored in the Malaysian population especially in a hot and humid condition this study was taken up. Methods: Nine heat adapted recreational runners (age : 25.4 ± 6.9 yr, body mass : 57.6 ± 8.4 kg; body height : 168.3 ± 7.6 cm) were recruited in this placebo-controlled double-blind randomized study. Subjects ingested 200 mg of PG one hour before the exercise test on treadmill at 70 per cent of their VO2max in a laboratory environment of 31 °C and 70 per cent relative humidity. They drank 3 ml/kg body weight of cool water every 20 min during the exercise to prevent adverse effects of dehydration. Blood samples were drawn every 20 min for the analysis of glucose, lactate, insulin and free fatty acids. Oxygen uptake was determined every 20 min while heart rate, body and skin temperatures, and ratings of perceived exertion (RPE) were recorded every 10 min during the trials. Results: Endurance running time to exhaustion did not differ between PG and placebo trials. Heart rate, skin temperature, core body temperature, oxygen uptake, RPE, plasma insulin, glucose, free fatty acid and lactate levels during the endurance exercise did not show any significant differences between the trials. Interpretation & conclusions: We conclude that acute supplementation of 200 mg of PG did not affect the endurance running performance of the heat-adapted male recreational runners in the heat.

Association of the infusion of Heteropterys aphrodisiaca and endurance training brings spermatogenetic advantages

The species Heteropterys aphrodisiaca is commonly used as a stimulant by popular medicine in the Cerrado, a savanna-like biome, Brazil. Recent studies have proved its protective effects on testes of animals submitted to treatment using Cyclosporine A, as well as its stimulus effect in increasing testosterone secretion. Therefore, the present study was designed to analyze whether the association of the plant infusion and endurance exercise could potentiate the stimulating effect. The animals were separated into 4 groups: two control (sedentary and trained) receiving water and two treated (sedentary and trained) receiving the plant infusion daily (104mg/day). The proportion of the seminiferous tubule compartment and interstitium was analyzed. Within the seminiferous epithelium, the number of Sertoli and germ cells were counted in order to evaluate whether the treatment would alter the spermatogenic dynamics, analyzing: the spermatogenic yield, the mitotic and meiotic indexes, the total number of germ cells and the Sertoli cell support capacity. Trained and treated animals showed increased spermatogenic yield and spermatogonia mitosis, and no significant differences in apoptotic indexes. Despite the results showing the same pattern regarding yield and mitotic index, the meiotic index was higher in the sedentary/treated group. Therefore, the H. aphrodisiaca infusion increased both the testosterone production and the spermatogonia mitosis, thus increasing the spermatogenic yield.

[ effect of melatonin on cardiovascular indices during exercise]

The purpose of this study was to determine the effect of melatonin ingestion on cardiopulmonary indices during rest, exercise and recovery period in female athletes. Heart rate [HR], blood pressure [BP] and maximal oxygen consumption [VO[2] max] were measured before and after ingestion of melatonin during exercise. Ten female basketball players [age 21.8 +/- 1.135 year, height 171.1 +/- 1 cm.676, weight 61.3 +/- 1.693kg], who were playing in Shiraz basketball league, were selected for this study based on the regularity of their menstrual cycle in the last 3 month. They all were homogenized according to their chronotype and had not any kind of disease. They performed the protocol at luteinizing phase of their menstrual cycles in two separate days with 72 hours interval at 11: 30 min in the morning. HR, BP and VO[2] max were measured at the first day. To assess their VO[2] max and other factors under study during exercise, they performed Bruce treadmill protocol to exhaustion and all above factors were measured during exercise either. At the second stage, 72 hrs after the ingestion of 10 mg melatonin, the HR, BP and VO[2] max were measured 30 minutes after ingesting supplement. The same procedure followed for exercise and recovery stages. Paired-samples T test used for data analysis [alpha = 0.05]. HR decreased significantly after ingesting melatonin during exercise [p=0.0001]. Ingesting melatonin did not affect resting BP but it significantly decreased BP during exercise and recovery. Furthermore, ingesting 10 mg of melatonin before exercise led to significant increase of subjects VO[2] max [p=0.0001]. The finding of this study shows that ingesting melatonin decreases HR, BP and BT during rest, exercise and recovery moreover it increases VO[2] max. In other term it increases endurance performance especially in warm environments. Then, athlete and coaches could use melatonin ingestion as a method to pre-cooling, modulating applied stresses to cardio respiratory system during exercise in warm environments, improve their endurance performance and increase efficacy of recovery period

Ginseng supplementation does not change lactate threshold and physical performances in physically active Thai men.

BACKGROUND: Ginseng has been one of the most popular herbs said to improve human exercise performance. Unclear and anecdotal information is known about the effect of ginseng on lactate threshold and aerobic performance in humans. OBJECTIVE: The purpose of the present study was to investigate the effect of ginseng supplementation on lactate threshold in physically active young men. MATERIAL AND METHOD: Sixty men from the Naval Medical Corps, Royal Thai Navy, aged 17- 22 years old, were randomized into either the ginseng (n = 30) or placebo (n = 30) group. The ginseng group took 3 grams of 100% ginseng orally, while the placebo group took an equal amount of lactose powder each day, for 8 weeks. Blood lactic acid levels for determination of lactate threshold (LT) were measured during an incremental cycle ergometer work. LT exercise performance, and heart rate (HR) responses to exercise were determined at baseline and after 8 weeks of ginseng and placebo consumption. Substrate oxidation rates during steady state exercise were assessed upon study completion. Selected markers for liver and kidney functions, including serum aspartate aminotransferase, alanine aminotransferase, blood urea nitrogen, and creatinine were monitored for possible side effects of ginseng. RESULTS: L T before and after 8 weeks of supplementation in the ginseng group (164.5 +/- 32.8 and 170.9 +/- 26.4 watts), and in the placebo group (163.7 + 25.1 and 163.7 + 17.3 watts) were not different (p = 0.448). Both groups had a similar pattern of exercise heart rate (p = 0.918), total exercise time (p = 0.241), and peak power output (p = 0.411). After 8 weeks, the magnitude of difference between ginseng and placebo groups on oxidation rates of fat (3.82 +/- 10.0 cal. kg(-1). min(-1), p = 0.704) or carbohydrate (4.36 +/- 12.6 cal. kg(-1). min(-1), p = 0.731) was not statistically significant. There were no abnormal changes of markers of liver and renal functions after ginseng administration. CONCLUSION: Daily administration of 3 g of ginseng for an 8-week period did not improve LT nor did it affect physical performances. Therefore, ginseng supplementation did not exert an ergogenic property on aerobic fitness enhancement in well-fit individuals.

Supplementary effect of carbohydrate-electrolyte drink on sports performance, lactate removal & cardiovascular response of athletes.

BACKGROUND AND OBJECTIVE: Carbohydrate-electrolyte drink has a significant role on energy balance during exercise. The present study was designed to investigate the effect of oral carbohydrate-electrolyte supplementation on sports performance and cardiovascular status of the national level male athletes during exercise and recovery. METHODS: A total of 10 male athletes (age range: 20-25 yr) were selected. The experiment was performed in laboratory (25 degrees C and 60% relative humidity) in two phases; phase 1 - no supplementation, and phase 2 - a 5 g per cent carbohydrate-electrolyte drink was given orally during exercise and a 12.5 g per cent carbohydrate-electrolyte drink during recovery. Subjects performed an exercise test at 70 per cent of VO(2)max. Performance time, heart rate during exercise and recovery were noted, blood samples were collected during exercise and recovery for the analysis of glucose and lactate levels in both the phases. RESULTS: Significant improvements were noted in total endurance time, heart rate responses and blood lactate during exercise at 70 per cent VO(2)max after the supplementation of 5 g per cent carbohydrate-electrolyte drink. However, no significant changes were noted in blood glucose and peak lactate level irrespective of supplementation of carbohydrate-electrolyte drink. Significant improvement in cardiovascular responses, blood glucose and lactate removal were noted during recovery following a 12.5 g per cent carbohydrate-electrolyte drink. INTERPRETATION AND CONCLUSION: Carbohydrate-electrolyte drink can increase endurance performance as well as enhance lactate removal and thereby delaying the onset of fatigue.

O efeito da cafeína no desempenho de ciclistas sob condçoes de alto risco térmico / Effect of caffeine in the performance of cyclists under high thermal risk

PURPOSE: To verify the effect of caffeine on yield time, the tympanic temperature and body weight with the administration of 5 and 9 mg/kg doses of caffeine and placebo, in cycling races under high thermal risk conditions. METHODS: Eight highly-trained cyclists were studied in 3 races of 45 km using the experimental model and double-blind with intra-subjects randomized. RESULTS: Air temperature ranged from 28.,5 and 32 degrees C and humidity between 71 e 78% with an index of WBGT varying between 24.5 degrees and 27 degrees C, figures that indicate high thermal risk. No significant differences were observed between variables assessed, yet yield time was lower with doses of 5 and 9 mg/kg caffeine than with placebo. CONCLUSION: These data indicate that heat and humidity conditions may be sufficient to mask the ergogenic benefit of caffeine in cycling races of prolonged duration. Therefore, isn't justifiable it's utilization in high thermal risk conditions.

Effect of sodium citrate ingestion on oxygen debt & exercise endurance during supramaximal exercise.

BACKGROUND & OBJECTIVES: Administration of alkalinizing agents has been shown to improve performance in high intensity exercise. The present investigation was undertaken to determine whether sodium citrate ingestion enhances supramaximal endurance performance on a cycle ergometer and to assess its effect on oxygen debt incurred for the same supramaximal energy output. METHODS: Ten untrained, healthy, males performed acute intense bicycle ergometry exercise in two sessions viz., without (control) and with sodium citrate ingestion (experimental) in a dose of 0.5 g/kg body weight. Pre-exercise O2 consumption, pulse rate (PR) and respiratory rate (RR)/minute were recorded before both sessions. Exhaustion time (ET) was noted and work done calculated in the control session. Post-exercise PR and RR/min were also recorded in both sessions of study. Venous blood samples were drawn post-exercise and analysed for pH and lactate. O2 debt incurred was calculated in both sessions. RESULTS: Work output in supramaximal exercise averaged 69.40 +/- 15.31 Watts in the control session. None of the subjects in the experimental session complained of fatigue even when the exhaustion time noted in the control session was reached. Post-exercise tachycardia and tachypnoea were both significantly less (P<0.05 and P<0.001 respectively) in subjects after the experimental session as compared to the control. O2 debt incurred and lowering of blood pH were also significantly less (P<0.001) in the post-citrate phase. However, serum lactate increased significantly (P<0.05) in subjects after the experimental session. INTERPRETATION & CONCLUSION: Ingestion of sodium citrate prior to supramaximal exercise resulted in a reduction in post exercise O2 debt incurred. Blood pH was almost normal despite a higher serum lactate concentration. This probably led to an enhancement in exercise performance.

Effects of caffeine on time to exhaustion in exercise performed below and above the anaerobic threshold

Controversy still exists concerning the potential ergogenic benefit of caffeine (CAF) for exercise performance. The purpose of this study was to compare the effects of CAF ingestion on endurance performance during exercise on a bicycle ergometer at two different intensities, i.e., approximately 10 percent below and 10 percent above the anaerobic threshold (AT). Eight untrained males, non-regular consumers of CAF, participated in this study. AT, defined as the intensity (watts) corresponding to a lactate concentration of 4mM, was determined during an incremental exercise test from rest to exhaustion on an electrically braked cycle ergometer. On the basis of these measurements, the subjects were asked to cycle until exhaustion at two different intensities, i.e., approximately 10 percent below and 10 percent above AT. Each intensity was performed twice in a double-blind randomized order by ingesting either CAF (5 mg/kg) or a placebo (PLA) 60 min prior to the test. Venous blood was analyzed for free fatty acid, glucose, and lactate, before, during, and immediately after exercise. Rating of perceived exertion and time to exhaustion were also measured during each trial. There were no differences in free fatty acids or lactate levels between CAF and PLA during and immediately after exercise for either intensity. Immediately after exercise glucose increased in the CAF trial at both intensities. Rating of perceived exertion was singificantly lower (CAF = 14.1 + 2.5 vs PLA = 16.6 + 2.4) and time to exhaustion was significantly higher (CAF = 46.54 + 8.05 min vs PLA = 32.42 + 14.81 min) during exercise below AT with CAF. However, there was no effect of CAF treatment on rating of perceived exertion (CAF = 18.0 + 2.7 vs PLA = 17.6 + 2.3) and time to exhaustion (CAF = 18.45 + 7.28 min vs PLA = 19.17 + 4.37 min) during exercise above AT. We conclude that in untrained subjects caffeine can improve endurance performance during prolonged exercise performed below AT and that decrease of perceived exertion can be involved in this process.

Short-term evaluation of captopril in patients with chronic left sided valvular regurgitations.

OBJECTIVE: To evaluate the clinical effects and the changes in cardiac performance of high- and low-dose captopril compared to placebo in patients with chronic symptomatic aortic regurgitation (AR), and/or mitral regurgitation (MR). PATIENTS AND METHODS: We randomized patients into three groups, placebo (Group 1), incremental daily doses of 50 mg (Group 2), and 100 mg captopril (Group 3). We compared exercise capacity before and after four-week of treatment. RESULTS: Treatment was well tolerated with no serious side effects including blood chemistry. There were no significant effects of treatment on left ventricular dimensions nor calculated left ventricular ejection fraction (LVEF) between groups (LVEF change -0.6%, -2.6%, 2.4%, in group 1, 2 and 3 respectively; p > 0.05). No difference of exercise duration between treatment and placebo arms (change by 13%, 12.8%, 16.4%, respectively; p > 0.05). However, there were trends in the number of the patients who improved in left ventricular performance (absolute LVEF change > 5% unit = 15%, 16%, and 42% respectively; p > 0.05) and exercise performance (exercise time improvement > 75 sec = 50%, 47%, and 68% respectively; p > 0.05) in high dose captopril treatment group. CONCLUSION: There was no significant improvement of left ventricular performance and exercise capacity after four-weeks' treatment of low and high dose captopril. Further study with a larger sample size, and longer follow-up period may be required.

Anti-stress activity in a muramyl-dipeptide.

N-Acetylmuramyl-L-alanyl-D-isoglutamine and some of its derivatives have been examined for anti-stress activity. Amongst these, N-palmitoylmuramyl-L-alanyl-D-isoglutamine is shown to considerably enhance the capacity of animals to endure various types of stress. This indicates that besides acting as immunomodulators and sleep regulators, muramyl dipeptides may also act as anti-stress agents.

Effects of caffeine on the rate of perceived exertion

The role of caffeine in improving performance in endurance exercises is controversial and its mechanism of action is not well understood. The purpose of the present study was to evaluate the effects of caffeine on the rate of perceived exertion (RPE) by exercising athletes. Six male non-smoking runners, aged 26.8 ñ 4.9 years (mean ñ SD), who had been in training continuously for at least two years before the experiment were studied. Mean maximum oxygen consumption (VO2max) was 61.21 ñ 5.36 ml kg**-1 min**-1. The subjects were asked to exercise on a bicycle ergometer for 3 min each at 300 and 600 kg m min**-1, after which the work load was elevated to 1200 kg m min**-1 and they exercised until exhaustion. In order to evaluate the effects of caffeine, the exercicse was performed twice following the ingestion of 200 ml decaffeinated coffee with and without caffeine (5 mg/kg body veight). Caffeine had no significant effect on exercise time, pulmonary ventilation, oxygen consumption, carbon dioxide extraction or exchange respiratory ratio, but the RPE was significantly lower (P<0.05) at the work load of 1200 kg m min**-1 after the ingestion of caffeine for both trials I and II. The present results suggest that metabolic acidosis and glycogen depletion were not the main causes of exhaustion

Effect of propranolol and phenoxybenzamine on muscle strength and physical endurance, and on exercise-induced changes in muscle glycogen and blood lactic acid levels in rats.

Propranolol and phenoxybenzamine (PBZ) had no major effect on swimming-endurance performance and skeletal muscle pulling-strength in rats. Propranolol, like exercise itself diminished the resting skeletal muscle glycogen (SMG) content, but the drug did not lower the resting blood lactic acid (BLA) levels. Propranolol significantly antagonised the 25-min exercise-induced BLA elevation, indicating that lactacidaemia is possibly a beta-receptor response. However, propranolol did not exhibit an overall beneficial effect on swimming endurance. PBZ had a negligible effect on maximal swimming time (MST) and had no major effects on the SMG content and BLA levels.