The Effects of Physical Fitness and Body Composition on Oxygen Consumption and Heart Rate Recovery After High-Intensity Exercise

The aim of this study was to investigate the potential relationship between excess post-exercise oxygen consumption (EPOC), heart rate recovery (HRR) and their respective time constants (tvo(2) and t(HR)) and body composition and aerobic fitness (VO(2)max) variables after an anaerobic effort. 14 professional cyclists (age = 28.4 +/- 4.8 years, height = 176.0 +/- 6.7 cm, body mass = 74.4 +/- 8.1 kg, VO(2)max = 66.8 +/- 7.6 mL. kg(-1) . min(-1)) were recruited. Each athlete made 3 visits to the laboratory with 24h between each visit. During the first visit, a total and segmental body composition assessment was carried out. During the second, the athletes undertook an incremental test to determine VO(2)max. In the final visit, EPOC (15-min) and HRR were measured after an all-out 30s Wingate test. The results showed that EPOC is positively associated with % body fat (r = 0.64), total body fat (r = 0.73), fat-free mass (r = 0.61) and lower limb fat-free mass (r = 0.55) and negatively associated with HRR (r = - 0.53, p < 0.05 for all). HRR had a significant negative correlation with total body fat and % body fat (r = - 0.62, r = - 0.56 respectively, p < 0.05 for all). These findings indicate that VO(2)max does not influence HRR or EPOC after high-intensity exercise. Even in short-term exercise, the major metabolic disturbance due to higher muscle mass and total muscle mass may increase EPOC. However, body fat impedes HRR and delays recovery of oxygen consumption after effort in highly trained athletes.

Effects of a probiotic soy product and physical exercise on formation of pre-neoplastic lesions in rat colons in a short-term model of carcinogenic

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

The impact of different types of physical activity on total and regional bone mineral density in young Brazilian athletes

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Evaluation of sixth grade primary schoolchildren's knowledge about avulsion and dental reimplantation

Dental trauma, particularly tooth avulsion, is a frequent cause of tooth loss in children, adolescents, and young adults. The avulsed tooth should be immediately reimplanted in its alveolus. This procedure can be performed by anyone at the accident site and not only by dental surgeons. Therefore, the purpose of this study is to evaluate the knowledge of sixth graders of the city of Aracatuba, SP, about dental avulsion and tooth reimplantation through a structured and standardized survey. Our sample consisted of 778 students. The data collected was processed using the program epiinfo 2000. Most students were around 12 years of age and 94.5% related to practice some kind of sports. Results demonstrated that the possibility of tooth reimplantation after dental avulsion is not acknowledged among these students and dental traumatism was associated to caries, toothache, and use of orthodontic appliances. Only 18.9% of the students associated dental traumatism to an impact trauma; 3.6% would store the tooth in milk, and 3.1% believed the tooth could be reimplanted by anyone present at the accident site. In summary, the results show an overall the lack of knowledge about dental traumatism and highlight the need of special programs designed to educate school-aged students about emergency procedures to handle cases of dental traumatisms.

Blood lactate response and critical speed in swimmers aged 10-12 years of different standards

It has previously been shown that measurement of the critical speed is a non-invasive method of estimating the blood lactate response during exercise. However, its validity in children has yet to be demonstrated. The aims of this study were: (1) to verify if the critical speed determined in accordance with the protocol of Wakayoshi et al. is a non-invasive means of estimating the swimming speed equivalent to a blood lactate concentration of 4 mmol . l(-1) in children aged 10-12 years; and (2) to establish whether standard of performance has an effect on its determination. Sixteen swimmers were divided into two groups: beginners and trained. They initially completed a protocol for determination of speed equivalent to a blood lactate concentration of 4 mmol . l(-1). Later, during training sessions, maximum efforts were swum over distances of 50, 100 and 200 m for the calculation of the critical speed. The speeds equivalent to a blood lactate concentration of 4 mmol . l(-1) (beginners = 0.82 +/- 0.09 m . s(-1), trained = 1.19 +/- 0.11 m . s(-1); mean +/- s) were significantly faster than the critical speeds (beginners = 0.78 +/- 0.25 m . s(-1), trained = 1.08 +/- 0.04 m . s(-1)) in both groups. There was a high correlation between speed at a blood lactate concentration of 4 mmol . l(-1) and the critical speed for the beginners (r = 0.96, P < 0.001), but not for the trained group (r = 0.60, P > 0.05). The blood lactate concentration corresponding to the critical speed was 2.7 +/- 1.1 and 3.1 +/- 0.4 mmol . l(-1) for the beginners and trained group respectively. The percent difference between speed at a blood lactate concentration of 4 mmol . l(-1) and the critical speed was not significantly different between the two groups. At all distances studied, swimming performance was significantly faster in the trained group. Our results suggest that the critical speed underestimates swimming intensity corresponding to a blood lactate concentration of 4 mmol . l(-1) in children aged 10-12 years and that standard of performance does not affect the determination of the critical speed.

Feed restriction and a diet's caloric value: The influence on the aerobic and anaerobic capacity of rats

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Manipulation of Rest Period Length Induces Different Causes of Fatigue in Vertical Jumping

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

The rating of perceived exertion predicts intermittent vertical jump demand and performance

The aims of this study were (a) to assess the ability of the rating of perceived exertion (RPE) to predict performance (i.e. number of vertical jumps performed to a fixed jump height) of an intermittent vertical jump exercise, and (b) to determine the ability of RPE to describe the physiological demand of such exercise. Eight healthy men performed intermittent vertical jumps with rest periods of 4, 5, and 6s until fatigue. Heart rate and RPE were recorded every five jumps throughout the sessions. The number of vertical jumps performed was also recorded. Random coefficient growth curve analysis identified relationships between the number of vertical jumps and both RPE and heart rate for which there were similar slopes. In addition, there were no differences between individual slopes and the mean slope for either RPE or heart rate. Moreover, RPE and number of jumps were highly correlated throughout all sessions (r=0.97-0.99; P0.001), as were RPE and heart rate (r=0.93-0.97; P0.001). The findings suggest that RPE can both predict the performance of intermittent vertical jump exercise and describe the physiological demands of such exercise.

Validity of critical frequency test for measuring table tennis aerobic endurance through specific protocol

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Evaluation of an Innovative Critical Power Model in Intermittent Vertical Jump

The aim of this study was to test if the critical power model can be used to determine the critical rest interval (CRI) between vertical jumps. Ten males performed intermittent countermovement jumps on a force platform with different resting periods (4.1 +/- 0.3 s, 5.0 +/- 0.4 s, 5.9 +/- 0.6 s). Jump trials were interrupted when participants could no longer maintain 95% of their maximal jump height. After interruption, number of jumps, total exercise duration and total external work were computed. Time to exhaustion (s) and total external work (J) were used to solve the equation Work = a + b . time. The CRI (corresponding to the shortest resting interval that allowed jump height to be maintained for a long time without fatigue) was determined dividing the average external work needed to jump at a fixed height (J) by b parameter (J/s). in the final session, participants jumped at their calculated CRI. A high coefficient of determination (0.995 +/- 0.007) and the CRI (7.5 +/- 1.6 s) were obtained. In addition, the longer the resting period, the greater the number of jumps (44 13, 71 28, 105 30, 169 53 jumps; p<0.0001), time to exhaustion (179 +/- 50, 351 +/- 120, 610 +/- 141, 1,282 +/- 417 s; p<0.0001) and total external work (28.0 +/- 8.3, 45.0 +/- 16.6, 67.6 +/- 17.8, 111.9 +/- 34.6 kJ; p<0.0001). Therefore, the critical power model may be an alternative approach to determine the CRI during intermittent vertical jumps.

Relationships and significance of lactate minimum, critical velocity, heart rate deflection and 3 000 m track-tests for running

The running velocities associated to lactate minimum (V-lm), heart rate deflection (V-HRd), critical velocity (CV), 3000 M (V-3000) and 10000 m performance (V-10km) were compared. Additionally the ability of V-lm and VHRd on identifying sustainable velocities was investigated.Methods. Twenty runners (28.5 +/- 5.9 y) performed 1) 3000 m running test for V3000; 2) an all-out 500 in sprint followed by 6x800 m incremental bouts with blood lactate ([lac]) measurements for V-lm; 3) a continuous velocity-incremented test with heart rate measurements at each 200 m for V-HRd; 4) participants attempted to 30 min of endurance test both at V-lm(ETVlm) and V-HRd(ETVHRd). Additionally, the distance-time and velocity-1/time relationships produced CV by 2 (500 m and 3000 m) or 3 predictive trials (500 m, 3000 m and distance reached before exhaustion during ETVHRd), and a 10 km race was recorded for V-10km.Results. The CV identified by different methods did not differ to each other. The results (m(.)min(-1)) revealed that V-.(lm) (281 +/- 14.8)< CV (292.1 +/- 17.5)=V-10km (291.7 +/- 19.3)< V-HRd (300.8 +/- 18.7)=V-3000 (304 +/- 17.5) with high correlation among parameters (P < 0.001). During ETVlm participants completed 30 min of running while on the ETVHRd they lasted only 12.5 +/- 8.2 min with increasing [lac].Conclusion. We evidenced that CV and Vim track-protocols are valid for running evaluation and performance prediction and the parameters studied have different significance. The V-lm reflects the moderate-high intensity domain (below CV), can be sustained without [lac] accumulation and may be used for long-term exercise while the V-HRd overestimates a running intensity that can be sustained for long-time. Additionally, V-3000 and V-HRd reflect the severe intensity domain (above CV).

Effects of recovery type after a judo combat on blood lactate removal and on performance in an intermittent anaerobic task

Aim. The objective of this study was to verify the effects of active (AR) and passive recovery (PR) after a judo match on blood lactate removal and on performance in an anaerobic intermittent task (4 bouts of upper body Wingate tests with 3-min interval between bouts; 4WT).Methods. The sample was constituted by 17 male judo players of different competitive levels: A) National (Brazil) and International medallists (n. 5). B) State (São Paulo) medallists (n. 7). Q City (São Paulo) medallists (n. 5). The subjects were submitted to: 1) a treadmill test for determination of VO2peak and velocity at anaerobic threshold (VAT); 2) body composition; 3) a 5-min judo combat, 15-min of AR or PR followed by 4WT.Results. The groups did not differ with respect to: body weight, VO2peak, VAT, body fat percentage, blood lactate after combats. No difference was observed in performance between AR and PR, despite a lower blood lactate after combat (10 and 15 min) during AR compared to PR. Groups A and B performed better in the high-intensity intermittent exercise compared to athletes with lower competitive level (C).Conclusion. The ability to maintain power output during intermittent anaerobic exercises can discriminate properly judo players of different levels. Lactate removal was improved with AR when compared to PR but AR did not improve performance in a subsequent intermittent anaerobic exercise.

The Lactate Minimum Test protocol provides valid measures of cycle ergometer VO2 peak

Aim. The aim of the present study was to investigate the validity of the Lactate Minimum Test (LMT) for the determination of peak VO2 on a cycle ergometer and to determine the submaximal oxygen uptake (VO2) and pulmonary ventilation (VE) responses in an incremental exercise test when it is preceded by high intensity exercise (i.e., during a LMT).Methods. Ten trained male athletes (triathletes and cyclists) performed 2 exercise tests in random order on an electromagnetic cycle ergometer: 1) Control Test (CT): an incremental test with an initial work rate of 100 W, and with 25 W increments at 3-min intervals, until voluntary exhaustion; 2) LMT: an incremental test identical to the CT, except that it was preceded by 2 supramaximal bouts of 30-sec (similar to120% VO(2)peak) with a 30-sec rest to induce lactic acidosis. This test started 8 min after the induction of acidosis.Results. There was no significant difference in peak VO2 (65.6+/-7.4 ml.kg(-1).min(-1); 63.8+/-7.5 ml.kg(-1).min(-1) to CT and LMT, respectively). However, the maximal power output (POmax) reached was significantly higher in CT (300.6+/-15.7 W) than in the LMT (283.2+/-16.0 W).VO2 and VE were significantly increased at initial power outputs in LMT.Conclusion. Although the LMT alters the submaximal physiological responses during the incremental phase (greater initial metabolic cost), this protocol is valid to evaluate peak VO2, although the POmax reached is also reduced.

Referring to judo's sports injuries in São Paulo State Championship

Objective. - In a pioneer way, we investigated the morbidity of sports injuries referred by judo athletes from São Paulo State Championship.Material and methods. - Data collection from 93 senior judokas in State of São Paulo Judo Championship, through Referred Morbidity Inquiry about last year.Results. - One hundred and ten events were registered with a distribution frequency gradient of sprain > contusion > strain > ligament injury > partial and total dislocation. The most injured body areas were: knee (26.3%), shoulder (21.8%), fingers (17.3%), and ankle (10.0%). The most risky situation was when the athlete was training (standing, applying a blow) and it can be explained by the frequent and unprepared exposition of the athletes. Yearly lesion rate was 1.18 injuries per athlete/year.Conclusion. - Sprains constitute the most common judo injury, and athletes are more susceptible when they apply blows; discussion about the direction that the prevention should be applied remains opened. (c) 2006 Elsevier Masson SAS. All rights reserved.