It has been suggested that the participation of alactic anaerobic metabolism(AAM) in physical activity can be estimated by calculating the fast componentof excess post-exercise oxygen consumption (EPOCFAST). Considering that... more
It has been suggested that the participation of alactic anaerobic metabolism(AAM) in physical activity can be estimated by calculating the fast componentof excess post-exercise oxygen consumption (EPOCFAST). Considering that maximalaccumulated oxygen deficit (MAOD) represents the total amount of energytransferred by anaerobic metabolisms, this study aimed to analyze whethersubtracting EPOCFAST from MAOD (MAODLA-1) provides a satisfactory estimate oflactic anaerobic metabolism (LAM). For this purpose, MAODLA-1 was compared withthe method by which the energy derived from blood lactate accumulation (MAODLA-2)is expressed as oxygen equivalent. Nine active adult men were submitted to fourexperimental sessions: 1) a maximal incremental exercise test until exhaustionon a cycle ergometer to measure the maximal oxygen consumption (VO2max) and theexternal power corresponding to VO2max (WVO2max); 2) and 3) sixconstant-workload tests (3 per session) at intensities below WVO2max; 4) oneconstant-...
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The purpose of this study was to analyze the relationship between the anaerobic components of the maximal accumulated oxygen deficit (MAOD) and of the 30-second Wingate anaerobic test (30-WAnT). Nine male physical education students... more
The purpose of this study was to analyze the relationship between the anaerobic components of the maximal accumulated oxygen deficit (MAOD) and of the 30-second Wingate anaerobic test (30-WAnT). Nine male physical education students performed: a) a maximal incremental exercise test; b) a supramaximal constant workload test to determine the anaerobic components of the MAOD; and c) a 30-WAnT to measure the peak power (PP) and mean power (MP). The fast component of the excess post-exercise oxygen consumption and blood lactate accumulation were measured after the supramaximal constant workload test in order to determine the contributions made by alactic (ALMET) and lactic (LAMET) metabolism. Significant correlations were found between PP and ALMET (r=0.71; P=0.033) and between MP and LAMET (r=0.72; P=0.030). The study results suggested that the anaerobic components of the MAOD and of the 30-WAnT are similarly applicable in the assessment of ALMET and LAMET during high-intensity exercise.
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This study examined the influence of the O2 kinetics on the running strategy adopted during a 10km running race in runners with different performance levels. Twenty-one runners (28.5 ± 5.3 years; 17.6 ± 7.3 cm; 66.3 ± 9.3 kg) performed 1)... more
This study examined the influence of the O2 kinetics on the running strategy adopted during a 10km running race in runners with different performance levels. Twenty-one runners (28.5 ± 5.3 years; 17.6 ± 7.3 cm; 66.3 ± 9.3 kg) performed 1) a test with increments of 1.2 km.h-1 every 3 min until exhaustion; 2) one 6-min test of constant velocity at 9 km.h-1 for determination of O2 kinetics and; 3) a 10 km time trial simulation. The subjects were divided into two groups, Moderated Performance (MP) and Low Perfomance (LP), based on the 10-km running performance. Mean velocity (MP= 16.9 ± 0.8 vs BP = 14.9 ± 1 km.h-1) on the 10km race was significantly different (p<0.05) between groups. There were no differences (p>0.05) between groups in any kinetics parameters analyzed. However, the O2 increase amplitude (A1 parameter) was inversely correlated with mean velocity (r =-0.48, p < 0.05) and with the partial velocities on time trial (r between-0.44 and-0.48, p < 0.05), except for ...
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Our aim was to analyze the pacing strategy adopted during middle-distance speed skating and to verify the influence of gender and race's performance level on pacing adopted. The races of male and female athletes during five stages of... more
Our aim was to analyze the pacing strategy adopted during middle-distance speed skating and to verify the influence of gender and race's performance level on pacing adopted. The races of male and female athletes during five stages of a World Cup, season 2009/2010, were included in the study. In both genders, the races were classified as high (HP) and low (LP) performance. The pacing adopted was similar between genders, with male athletes being faster throughout the race (P < 0.05). In both genders, the HP races were more aggressive in all intervals compared to LP races (P < 0.05), regardless of gender. Although performance is different between genders, the pacing adopted was similar between them in faster and slower races, suggesting that the technical in elite athletes seems to be a determinant factor in choice of adopted pacing strategy.
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The main purpose of this study was to compare the effect of the constant load and self-paced exercise with similar total work on autonomic control after endurance exercise. Ten physically active men were submitted to (i) a maximal... more
The main purpose of this study was to compare the effect of the constant load and self-paced exercise with similar total work on autonomic control after endurance exercise. Ten physically active men were submitted to (i) a maximal incremental exercise test, (ii) a 4-km cycling time trial (4-km TT), and (iii) a constant workload test with identical total external work performed at 4-km TT. Gas exchange was measured throughout the tests, while blood lactate, heart rate, and heart rate variability (HRV) were measured during the passive recovery. Power output measured at the last lap (i.e. 3600-4000 m) of 4-km TT (316 ± 89 W) was statistically higher than power output measured at the end of the constant workload exercise (211 ± 42 W). The 4-km TT produced higher values of blood lactate concentration (8.8 ± 2.1 mmol L) than the constant workload test (7.8 ± 2.1 mmol L). The heart rate recovery measured at 60 s (constant workload: 37 ± 7 bpm; 4-km TT: 30 ± 6) and 120 s (constant workload:...
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The aim of the present study was to determine whether physiological factors and maximal dynamic strength are able to determine the peak treadmill speed (PTS) in physically active individuals. One hundred and fifty physically active... more
The aim of the present study was to determine whether physiological factors and maximal dynamic strength are able to determine the peak treadmill speed (PTS) in physically active individuals. One hundred and fifty physically active healthy males voluntarily visit the laboratory on three separate occasions and underwent the following activities: first visit: IPAQ (short version), anthropometric measurements, and a maximal incremental test performed for physiological variables (maximal oxygen uptake ( ) and respiratory compensation point (RCP); second visit: constant speed test for running economy (RE) measurement, and familiarization with the maximum dynamic strength (1RM) test in the leg press exercise; third visit: 1RM test. The stepwise multiple regression model selected four independent variables to predict PTS (RCP, , RE, and 1RM). RCP explained 59% (p < 0.001) of variance in PTS, whereas , RE and 1RM accounted for additional 8% (p < 0.001), 4% (p < 0.001), and 1.4% (p ...
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The purpose of this study was to identify the main determinants of the self-selected pacing strategy during a 10-km running time trial. Twenty eight male long-distance runners performed the following tests: (a) maximal incremental... more
The purpose of this study was to identify the main determinants of the self-selected pacing strategy during a 10-km running time trial. Twenty eight male long-distance runners performed the following tests: (a) maximal incremental treadmill test, (b) economy running test, (c) maximum dynamic strength test, and (d) 10-km running time trial on an outdoor track. A stepwise multiple regression model was used to identify the contribution of rating of perceived exertion (RPE), physiological, and muscular parameters on the pacing strategy adopted by athletes. In the start phase (first 400 m), RPE accounted for 72% (p = 0.001) of the pacing variance. Peak treadmill speed (PTS) measured during a maximal incremental test explained 52% (p = 0.001) of the pacing variance during the middle phase (400-9,600 m), whereas maximal oxygen uptake and maximum dynamic strength accounted for additional 23% (p = 0.002) and 5% (p = 0.003), respectively. In the end phase (last 400 m), PTS accounted alone for 66% (p = 0.003) of the pacing variance. These data suggest that predictors of the pacing strategy during a 10-km running time trial have a transitional behavior from perceptive (start phase) to muscular and physiological factors (middle and end phases).
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The objective of this study was to analyze the influence of the presence and absence of competitors on pacing, overall running performance, and mood state during a self-paced 3-km run. Nine recreational runners participated in this study.... more
The objective of this study was to analyze the influence of the presence and absence of competitors on pacing, overall running performance, and mood state during a self-paced 3-km run. Nine recreational runners participated in this study. They performed the following tests: a) an incremental test to exhaustion to measure the respiratory compensation point (RCP), maximal oxygen uptake, and peak treadmill speed; b) a submaximal speed constant test to measure running economy; and c) two 3-km running time trials performed collectively (COL, head-to-head competition) or individually (IND, performed alone) to establish pacing and running performance. The COL condition was formed of a group of four runners or five runners. Runners were grouped by matched performance times and to retain head-to-head characteristics.A mood state profile questionnaire was completed before and after the 3-km running time trial. The overall performance was better in the COL than in the IND (11.75 ± 0.05 min vs. 12.25 ± 0.06 min, respectively; p = 0.04). The running speeds during the first 500 m were significantly greater in COL (16.8 ± 2.16 km·h−1) than in IND (15.3 ± 2.45 km·h−1) (p = 0.03).The gain in running speed from IND to COL during the first 400 m (i.e. running speed in COL less running speed in IND) was significantly correlated with the RCP (r = 0.88; p = 0.05). The vigor score significantly decreased from pre- to post-running in COL (p=0.05), but not in IND (p=0.20). Additionally, the post running vigor was significantly higher in IND compared to COL (p = 0.03).These findings suggested that the presence of competitors induces a fast start, which results in an improved overall performance and reduced post-exercise vigor scores, compared to an individual run.
Research Interests: Nonparametric Statistics, Running, Biological Sciences, Affect, Humans, and 12 moreMale, Young Adult, Computer User Interface Design, Adult, Time Factors, Exercise Test, Oxygen Consumption, Surveys and Questionnaires, Competitive Behavior , Psychology and Cognitive Sciences, Medical and Health Sciences, and physical exertion
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The main purpose of this study was to determine the relative contributions of the aerobic and glycolytic systems during an incremental exercise test (IET). Ten male recreational long-distance runners performed an IET consisting of... more
The main purpose of this study was to determine the relative contributions of the aerobic and glycolytic systems during an incremental exercise test (IET). Ten male recreational long-distance runners performed an IET consisting of three-minute incremental stages on a treadmill. The fractions of the contributions of the aerobic and glycolytic systems were calculated for each stage based on the oxygen uptake and the oxygen energy equivalents derived by blood lactate accumulation, respectively. Total metabolic demand (WTOTAL) was considered as the sum of these two energy systems. The aerobic (WAER) and glycolytic (WGLYCOL) system contributions were expressed as a percentage of the WTOTAL. The results indicated that WAER (86-95%) was significantly higher than WGLYCOL (5-14%) throughout the IET (p < 0.05). In addition, there was no evidence of the sudden increase in WGLYCOL that has been previously reported to support to the "anaerobic threshold" concept. These data suggest ...
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This study analyzed the effect of static stretching on performance during drop jumps. Furthermore, we investigated if a reduction in drop height would compensate the stretching-caused alterations. Ten physically active male subjects... more
This study analyzed the effect of static stretching on performance during drop jumps. Furthermore, we investigated if a reduction in drop height would compensate the stretching-caused alterations. Ten physically active male subjects performed drop jumps at four different drop heights without static stretching for the optimal drop height determination. After, they performed drop jumps on two drop heights with static stretching previously. The jump height, contact time and reactive strength index were significantly affected by static stretching. However, only the contact time was significantly improved by the reduction in drop height with previous static stretching. Our results suggest that the decrement in performance after static stretching could be partially compensated by a reduction in drop height, which decreases the contact time near a non-stretching jump condition. This can be explained by the lower landing velocity and, possibly, the smaller reduction in the activation of the...
Research Interests: Skeletal muscle biology, Running, Multidisciplinary, Humans, Male, and 3 morePLoS one, Adult, and Time Factors
Este estudo examinou a influência da cinética on do consumo de oxigênio (<img border=0 width=32 height=32 id="_x0000_i1082" src="../../../../img/revistas/rbme/v17n5/img01.jpg">O2) sobre a estratégia de corrida... more
Este estudo examinou a influência da cinética on do consumo de oxigênio (<img border=0 width=32 height=32 id="_x0000_i1082" src="../../../../img/revistas/rbme/v17n5/img01.jpg">O2) sobre a estratégia de corrida adotada durante uma corrida de 10km em corredores com diferentes níveis de desempenho. Vinte e um corredores (28,5 ± 5,3 anos; 172,6 ± 7,3cm; 66,3 ± 9,3kg) realizaram: 1) um teste com incrementos de 1,2km.h-1 a cada três min até a exaustão; 2) um teste de seis minutos de velocidade constante a 9km.h-1 para identificar a cinética do <img border=0 width=32 height=32 id="_x0000_i1081" src="../../../../img/revistas/rbme/v17n5/img01.jpg">O2; e 3) uma simulação de prova de 10km. Os sujeitos foram divididos em moderada (MP) e baixa (BP) performance de acordo com o tempo gasto para completar a prova de 10km. A velocidade média (MP = 16,9 ± 0,8 vs. BP = 14,9 ± 1km.h-1) na prova de 10km diferenciou significativamente (p < 0,05) entr...
The purpose of this study was to identify the main determinants of the self-selected pacing strategy during a 10-km running time trial. Twenty eight male long-distance runners performed the following tests: (a) maximal incremental... more
The purpose of this study was to identify the main determinants of the self-selected pacing strategy during a 10-km running time trial. Twenty eight male long-distance runners performed the following tests: (a) maximal incremental treadmill test, (b) economy running test, (c) maximum dynamic strength test, and (d) 10-km running time trial on an outdoor track. A stepwise multiple regression model was used to identify the contribution of rating of perceived exertion (RPE), physiological, and muscular parameters on the pacing strategy adopted by athletes. In the start phase (first 400 m), RPE accounted for 72% (p = 0.001) of the pacing variance. Peak treadmill speed (PTS) measured during a maximal incremental test explained 52% (p = 0.001) of the pacing variance during the middle phase (400-9,600 m), whereas maximal oxygen uptake and maximum dynamic strength accounted for additional 23% (p = 0.002) and 5% (p = 0.003), respectively. In the end phase (last 400 m), PTS accounted alone for 66% (p = 0.003) of the pacing variance. These data suggest that predictors of the pacing strategy during a 10-km running time trial have a transitional behavior from perceptive (start phase) to muscular and physiological factors (middle and end phases).