Wladimir Rafael Beck

Validity of the running anaerobic sprint test for assessing anaerobic power and predicting short-distance performances.

Zagatto, AM, Beck, WR, and Gobatto, CA. Validity of the running anaerobic sprint test for assessing anaerobic power and predicting short-distance performances. J Strength Cond Res 23(6): 1820-1827, 2009-The purpose of this study was to investigate the reliability and validity of the running anaerobic sprint test (RAST) in anaerobic assessment and predicting short-distance performance. Forty members of the armed forces were recruited for this study (age 19.78 ± 1.18 years; body mass 70.34 ± 8.10 kg; height 1.76 ± 0.53 m; body fat 15.30 ± 5.65 %). The RAST test was applied to six 35-meter maximal running performances with a 10-second recovery between each run; the peak power, mean power, and the fatigue index were measured. The study was divided in two stages. The first stage investigated the reliability of the RAST using a test-retest method; the second stage aimed to evaluate the validity of the RAST comparing the results with the Wingate test and running performances of 35, 50, 100, 200, and 400 m. There were not significant differences between test-retest scores in the first stage of the study (p > 0.05) and were found significant correlations between these variables (intraclass correlation coefficient ≅0.88). The RAST had significant correlations with the Wingate test (peak power r = 0.46; mean power r = 0.53; fatigue index r = 0.63) and 35, 50, 100, 200, and 400 m performances scores (p < 0.05). The advantage of using the RAST for measuring anaerobic power is that it allows for the execution of movements more specific to sporting events that use running as the principal style of locomotion, is easily applied and low cost, and due to its simplicity can easily be incorporated into routine training. We concluded that this procedure is reliable and valid, and can be used to measure running anaerobic power and predict short-distance performances.

Continuous Aerobic Training in Individualized Intensity Avoids Spontaneous Physical Activity Decline and Improves MCT1 Expression in Oxidative Muscle of Swimming Rats

Although aerobic training has been shown to affect the lactate transport of skeletal muscle, there is no information concerning the effect of continuous aerobic training on spontaneous physical activity (SPA). Because every movement in daily life (i.e., SPA) is generated by skeletal muscle, we think that it is possible that an improvement of SPA could affect the physiological properties of muscle with regard to lactate transport. The aim of this study was to evaluate the effect of 12 weeks of continuous aerobic training in individualized intensity on SPA of rats and their gene expressions of monocarboxylate transporters (MCT) 1 and 4 in soleus (oxidative) and white gastrocnemius (glycolytic) muscles. We also analyzed the effect of continuous aerobic training on aerobic and anaerobic parameters using the lactate minimum test (LMT). Sixty-day-old rats were randomly divided into three groups: a baseline group in which rats were evaluated prior to initiation of the study; a control group (Co) in which rats were kept without any treatment during 12 weeks; and a chronic exercise group (Tr) in which rats swam for 40 min/day, 5 days/week at 80% of anaerobic threshold during 12 weeks. After the experimental period, SPA of rats was measured using a gravimetric method. Rats had their expression of MCTs determined by RT-PCR analysis. In essence, aerobic training is effective in maintaining SPA, but did not prevent the decline of aerobic capacity and anaerobic performance, leading us to propose that the decline of SPA is not fully attributed to a deterioration of physical properties. Changes in SPA were concomitant with changes in MCT1 expression in the soleus muscle of trained rats, suggestive of an additional adaptive response toward increased lactate clearance. This result is in line with our observation showing a better equilibrium on lactate production-remotion during the continuous exercise (LMT). We propose an approach to combat the decline of SPA of rats in their home cages. This new finding is worth for scientists who work with animal models to study the protective effects of exercise.

Melatonin is an Ergogenic Aid for Exhaustive Aerobic Exercise only during the Wakefulness Period

This study tested the ergogenic effects of acute administration of melatonin on exhaustive exercise (tlim) at the anaerobic threshold intensity (iAnT) during periods of lower (L) and higher (H) spontaneous physical activity in swimming rats. Additionally, we evaluated the time of day effect on aerobic exercise tolerance. The periods of L and H were determined gravimetrically. All animals were subjected to an incremental test to determine the iAnT. Melatonin was administered (10 mg.kg(-1), intraperitoneal) and after 30 min, the rats were subjected to tlim during the L (LM) or H (HM) period. Control groups were called LC and HC. The criterion of significance was 5%. Melatonin enhanced tlim by 169% during H (HC=72 min; HM=194 min; P<0.01; ES=1.23) and by 90% during L (LC=31 min vs. LM=59 min; P=0.39; ES=1.18), demonstrating a significant effect on tlim (F=10.35; P<0.01) and a strong effect size (ES). Additionally, tlim was higher during H (F=14.24; P<0.01). Melatonin is a reasonable ergogenic aid, particularly during the wakefulness period, and the exercise tolerance is dependent on the time of day for swimming rats.

Melatonin Has An Ergogenic Effect But Does Not Prevent Inflammation and Damage In Exhaustive Exercise

It is well documented that exhaustive physical exercise leads to inflammation and skeletal muscle tissue damage. With this in mind, melatonin has been acutely administered before physical exercise; nevertheless, the use of melatonin as an ergogenic agent to prevent tissue inflammation and damage remains uncertain. We evaluated the effects of melatonin on swimming performance, muscle inflammation and damage and several physiological parameters after exhaustive exercise at anaerobic threshold intensity (iLAn) performed during light or dark circadian periods. The iLAn was individually determined and two days later, the animals performed an exhaustive exercise bout at iLAn 30 minutes after melatonin administration. The exercise promoted muscle inflammation and damage, mainly during the dark period, and the exogenous melatonin promoted a high ergogenic effect. The expressive ergogenic effect of melatonin leads to longer periods of muscle contraction, which superimposes a possible melatonin protective effect on the tissue damage and inflammation.

Wide housing space and chronic exercise enhance physical fitness and adipose tissue morphology in rats

The current cages commonly used in animal experiments can prevent rats from engaging in most forms of natural locomotion behaviors. These animals tend to exhibit sedentary habits. Here, we show that a combination of wide housing space and training exercise helps to reduce white adipose mass and to increase brown adipose mass. Thus, this combination is a useful strategy for truly enhancing the physical fitness of captive rats commonly used in exercise-related interventional studies and to maximize their welfare.

Computational and Complex Network Modeling for Analysis of Sprinter Athletes’ Performance in Track Field Tests

Sports and exercise today are popular for both amateurs and athletes. However, we continue to seek the best ways to analyze best athlete performances and develop specific tools that may help scientists and people in general to analyze athletic achievement. Standard statistics and cause-and-effect research, when applied in isolation, typically do not answer most scientific questions. The human body is a complex holistic system exchanging data during activities, as has been shown in the emerging field of network physiology. However, the literature lacks studies regarding sports performance, running, exercise, and more specifically, sprinter athletes analyzed mathematically through complex network modeling. Here, we propose complex models to jointly analyze distinct tests and variables from track sprinter athletes in an untargeted manner. Through complex propositions, we have incorporated mathematical and computational modeling to analyze anthropometric, biomechanics, and physiological interactions in running exercise conditions. Exercise testing associated with complex network and mathematical outputs make it possible to identify which responses may be critical during running. The physiological basis, aerobic, and biomechanics variables together may play a crucial role in performance. Coaches, trainers, and runners can focus on improving specific outputs that together help toward individuals’ goals. Moreover, our type of analysis can inspire the study and analysis of other complex sport scenarios.

Avaliação da capacidade aeróbia determinada por respostas sanguíneas e ventilatórias em quatro diferentes ergômetros

DOI: http://dx.doi.org/10.5007/1980-0037.2013v15n3p350 The objective of the study was to compare intensities of respiratory compensation point (RCP),anaerobic threshold at onset blood lactate accumulation (OBLA3,5), and anaerobic threshold at lactate abrupt increase (AnTLAC) determined in four different ergometers. Hence, eleven table tennis players (19±1 years) performed graded exercise tests on cycle ergometer, arm cranking ergometer, treadmill and specific table tennis test. The respiratory response and lactatemia were measured during the tests. We did not find significant diferences among RCP, AnTLAC and OBLA3,5 in arm cranking ergometer (63.4±4.8W, 66.9±4.5W and 64.5±6.1W, respectively), treadmill (11.4±0.4 km.h-1, 11.3±0.3 km.h-1 and 11.1±0.3 km.h-1, respectively), and specific table tennis test (40.5±1.8 bolas.min-1, 42.6±3.6bolas.min-1 and 42.8±5.6bolas.min-1,respectively). However, the OBLA 3,5 (131.9±6.6W) was significantly lower than RCP (149.3±4.9W) and AnTLAC (149.3±4.7W) in the cycle ergometer. Strong and significant correlation coefficients were found in the specific test for all methods (r range 0.83 to 0.95), in arm cranking ergometer between RCP and OBLA 3,5 (r=0.78), and on treadmill running between OBLA3,5 and AnTLAC (r=0.76).Therefore, we conclude that RCP, OBLA3,5 and AnTLAC seem to correspond to the same physiological phenomenon, mostly during specific table tennis test.