151
|
|
152
|
Pereira BC, Filho LAL, Alves GF, Pauli JR, Ropelle ER, Souza CT, Cintra DE, Saad MJA, Silva ASR. A new overtraining protocol for mice based on downhill running sessions. Clin Exp Pharmacol Physiol 2013; 39:793-8. [PMID: 22632058 DOI: 10.1111/j.1440-1681.2012.05728.x] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
1. The purpose of the present study was to verify whether a downhill running protocol was able to induce non-functional overreaching in > 75% of mice. 2. Mice were divided into control (C), trained (TR) and overtrained (OTR) groups. Bodyweight and food intake were recorded weekly. The incremental load test (ILT) and the exhaustive test (ET) were used to measure performance before and after aerobic training and overtraining protocols. 3. Although the bodyweight of the OTR group was lower than that of the C group at the end of Week 7, the food intake of the OTR group was higher than that of the C and TR groups at the end of Week 8. Evaluation of results from the ILT and ET revealed significant intra- and inter-group differences: whereas the parameters measured by both tests increased significantly in the TR group, they were significantly decreased in the OTR group. 4. In conclusion, this new overtraining protocol based on downhill running sessions induced non-functional overreaching in 100% of mice.
Collapse
Affiliation(s)
- Bruno C Pereira
- School of Physical Education and Sport of Ribeirão Preto, University of São Paulo, Ribeirão Preto, Brazil
| | | | | | | | | | | | | | | | | |
Collapse
|
153
|
Validity and reliability of the 45-15 test for aerobic fitness in young soccer players. Int J Sports Physiol Perform 2013; 9:525-31. [PMID: 23295221 DOI: 10.1123/ijspp.2012-0165] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
The aim of this study was to examine the reliability and validity of a popular field test for aerobic fitness used in soccer (45-15) in Italy. Alternating progressive 45-s runs with 15 s passive recovery until exhaustion, the test considers peak speed (PS) as a reflection of maximal aerobic speed (MAS). The validity and reliability of the 45-15 was assessed in 18 young male soccer players (age 16.7 ± 1.8 y, body mass 70 ± 7.45 kg, height 177 ± 0.5 cm, 55.62 ± 5.56 mL · kg-1 ·min-1) submitted to laboratory testing for aerobic fitness and repeatedly to the 45-15. Results showed that 45-15 PS was significantly related to VO2max (r = .80, P < .001, 95%CI .47-.93) and MAS (r = .78, P = .001, 95%CI .43-.93). No significant bias between MAS 45-15 PS (P = .11) was found during the measurement-consistency study. Receiver-operating-characteristic (ROC) analysis showed that 45-15 PS was sensitive in detecting VO2max changes in subjects as revealed by area under the curve (.97; 95%CI .73-1). Players with peak 45-15 speed equal to or above 16.5 km/h (ie, ROC cutoff) may be considered to have good aerobic fitness. In light of this study's findings, the 45-15 test may be considered a reliable and valid test to evaluate meaningful information to direct generic aerobic training in soccer.
Collapse
|
154
|
Emhoff CAW, Messonnier LA, Horning MA, Fattor JA, Carlson TJ, Brooks GA. Gluconeogenesis and hepatic glycogenolysis during exercise at the lactate threshold. J Appl Physiol (1985) 2012; 114:297-306. [PMID: 23239870 DOI: 10.1152/japplphysiol.01202.2012] [Citation(s) in RCA: 77] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Because the maintenance of glycemia is essential during prolonged exercise, we examined the effects of endurance training, exercise intensity, and plasma lactate concentration ([lactate]) on gluconeogenesis (GNG) and hepatic glycogenolysis (GLY) in fasted men exercising at, and just below, the lactate threshold (LT), where GNG precursor lactate availability is high. Twelve healthy men (6 untrained, 6 trained) completed 60 min of constant-load exercise at power outputs corresponding to their individual LT. Trained subjects completed two additional 60-min sessions of constant-load exercise: one at 10% below the LT workload (LT-10%), and the other with a lactate clamp (LT-10%+LC) to match the [lactate] of the LT trial. Flux rates were determined by primed continuous infusion of [6,6-(2)H(2)]glucose, [3-(13)C]lactate, and [(13)C]bicarbonate tracers during 90 min of rest and 60 min of cycling. Exercise at LT corresponded to 67.6 ± 1.3 and 74.8 ± 1.7% peak O(2) consumption in the untrained and trained subjects, respectively (P < 0.05). Relative exercise intensity was matched between the untrained group at LT and the trained group at LT-10%, and [lactate] during exercise was matched in the LT and LT-10%+LC trials via exogenous lactate infusion. Glucose kinetics (rate of appearance, rate of disposal, and metabolic clearance rate) were augmented with the lactate clamp. GNG was decreased in the trained subjects exercising at LT and LT-10% compared with the untrained subjects, but increasing [lactate] in the LT-10%+LC trial significantly increased GNG (4.4 ± 0.9 mg·kg(-1)·min(-1)) compared with its corresponding control (1.7 ± 0.4 mg·kg(-1)·min(-1), P < 0.05). Hepatic GLY was higher in the trained than untrained subjects, but not significantly different across conditions. We conclude that GNG plays an essential role in maintaining total glucose production during exercise in fasted men, regardless of training state. However, endurance training increases the ability to achieve a higher relative exercise intensity and absolute power output at the LT without a significant decrease in GNG. Furthermore, raising systemic precursor substrate availability increases GNG during exercise, but not at rest.
Collapse
Affiliation(s)
- Chi-An W Emhoff
- Department of Integrative Biology, University of California Berkeley, Berkeley, CA 94720-3140, USA
| | | | | | | | | | | |
Collapse
|
155
|
Madrid B, Sotero RDC, Campbell CSG, Sousa IRCD, Carvalho FO, Vieira A, Rauber SB, Franco CBS, Simões HG. Reprodutibilidade do protocolo de lactato mínimo com intensidade do esforço prévio individualizado pela PSE. MOTRIZ: REVISTA DE EDUCACAO FISICA 2012. [DOI: 10.1590/s1980-65742012000400003] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Introdução: O protocolo de lactato mínimo (LM) é precedido de um esforço máximo para indução a hiperlactatemia. Objetivo: Verificar a reprodutibilidade de um teste de LM com indução à hiperlactatemia realizada em teste incremental com cargas individualizadas através da percepção subjetiva de esforço (PSE). Metodologia: A amostra foi composta por 20 estudantes fisicamente ativos (25,4 ± 4,1 anos; 14,1 ± 5,0 % gordura), submetidos a dois testes de LM com metodologia idêntica. A indução a hiperlactatemia foi realizada por um teste com quatro estágios, com duração de três minutos cada e cargas individualizadas pela PSE (níveis 10, 13, 16 e o último estágio 17-20 até a exaustão voluntária). Após oito minutos de recuperação o teste progressivo começou com carga inicial de 75 W e incrementos de 25 W a cada três minutos, até a exaustão. Resultados: As intensidades de LM 1 (155,0 ± 23,8 W) e LM 2 (157,5 ± 27,0 W) não diferiram estatisticamente (p = 0,795) e de uma maneira geral apresentaram boa reprodutibilidade (CCI = 0,79) e concordância [-2,5 W de média da diferença e ± 41,8 W de abas]. Conclusão: O teste de LM, com cargas para hiperlactatemia individualizadas pela PSE, se mostrou reprodutível em indivíduos fisicamente ativos.
Collapse
|
156
|
Almeida JA, Petriz BDA, da Costa Gomes CP, Pereira RW, Franco OL. Assessment of maximal lactate steady state during treadmill exercise in SHR. BMC Res Notes 2012. [PMID: 23194345 PMCID: PMC3544571 DOI: 10.1186/1756-0500-5-661] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
Background Spontaneously hypertensive rats (SHR) are one of the main animal models used for studying the effects of exercise on hypertension. Therefore, the determination of adequate intensity has been essential for secure and optimized exercise prescriptions concerning hypertensive subjects. This study aimed to identify the MLSS in SHR by using a treadmill test to improve the protocols and further prescriptions of exercise intensity. Findings In order to carry out this determination, SHR (n = 10) animals (~17.5 weeks; 227.4 ± 29.3 g; 172.4 ± 8.1 mmHg systolic blood pressure) were divided into two groups (G1 n = 5; G2 n = 5). Rats underwent a test with three different velocities to determine the MLSS. The MLSS was considered as the highest effort intensity where the blood lactate did not vary more than 1 mmol.L-1 from the 10th to the 25th minute. The MLSS was reached at a velocity of 20 m.min-1 with 3.8 ± 0.5 mmol.L-1 of lactate for G1. Additionally, the results were validated in G2. However, when the test was applied at 25 m.min-1, there was no stabilization of BLC in G1 and G2. Conclusions In this study it was possible to identify the MLSS in SHR rats, which is an excellent evaluation tool to control exercise intensity. These data are of considerable importance in studies using physical exercise as a means of research in hypertension and may lead to the intensity of exercise being prescribed more appropriately.
Collapse
Affiliation(s)
- Jeeser Alves Almeida
- Centro de Análises Proteômicas e Bioquímicas, Programa de Pós-Graduação em Ciências Genômicas e Biotecnologia, Universidade Católica de Brasília, SGAN, Quadra 916, Módulo B, Brasília, DF, 70790-160, Brazil
| | | | | | | | | |
Collapse
|
157
|
Mezzani A, Hamm LF, Jones AM, McBride PE, Moholdt T, Stone JA, Urhausen A, Williams MA. Aerobic exercise intensity assessment and prescription in cardiac rehabilitation: a joint position statement of the European Association for Cardiovascular Prevention and Rehabilitation, the American Association of Cardiovascular and Pulmonary Rehabilitation and the Canadian Association of Cardiac Rehabilitation. Eur J Prev Cardiol 2012; 20:442-67. [PMID: 23104970 DOI: 10.1177/2047487312460484] [Citation(s) in RCA: 298] [Impact Index Per Article: 24.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Aerobic exercise intensity prescription is a key issue in cardiac rehabilitation, being directly linked to both the amount of improvement in exercise capacity and the risk of adverse events during exercise. This joint position statement aims to provide professionals with up-to-date information regarding the identification of different exercise intensity domains, the methods of direct and indirect determination of exercise intensity for both continuous and interval aerobic training, the effects of the use of different exercise protocols on exercise intensity prescription and the indications for recommended exercise training prescription in specific cardiac patients' groups. The importance of functional evaluation through exercise testing prior to starting an aerobic training program is strongly emphasized, and ramp incremental cardiopulmonary exercise test, when available, is proposed as the gold standard for a physiologically comprehensive exercise intensity assessment and prescription. This may allow a shift from a 'range-based' to a 'threshold-based' aerobic exercise intensity prescription, which, combined with thorough clinical evaluation and exercise-related risk assessment, could maximize the benefits obtainable by the use of aerobic exercise training in cardiac rehabilitation.
Collapse
Affiliation(s)
- Alessandro Mezzani
- Salvatore Maugeri Foundation IRCCS, Scientific Institute of Veruno, Exercise Pathophysiology Laboratory, Cardiac Rehabilitation Division, Italy.
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
158
|
Ribeiro C, Cambri LT, Dalia RA, de Araújo MB, Botezelli JD, Sponton ACDS, de Mello MAR. Effects of physical training with different intensities of effort on lipid metabolism in rats submitted to the neonatal application of alloxan. Lipids Health Dis 2012; 11:138. [PMID: 23067133 PMCID: PMC3532126 DOI: 10.1186/1476-511x-11-138] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2012] [Accepted: 10/09/2012] [Indexed: 12/22/2022] Open
Abstract
BACKGROUND Type 2 diabetes mellitus (T2DM) is a chronic disease that is characterized by insulin resistance. Its development is directly connected with the inability of insulin to exert its action, not just on carbohydrate metabolism but also on primarily on lipid metabolism. The present study aimed to compare the effects of continuous, intermittent, and strength training on serum and tissue variables on the lipid metabolism of alloxan rats. METHODS Wistar rats were divided into eight groups: sedentary alloxan (SA), sedentary control (SC), continuous training alloxan (CA), intermittent training alloxan (IA), strength training alloxan (StA), continuous training control (CC), intermittent training control (IC) and strength training control (StC). Alloxan (250 mg/kg bw) was injected into neonatal rats at 6 days of age. The continuous training protocol consisted of 12 weeks of swimming training for 1 uninterrupted hour/day, five days/week, supporting a load that was 5% bw. The intermittent training protocol consisted of 12 weeks of swimming training with 30 s of activity interrupted by 30 s of rest, for a total of 20 min/day, five days/week, supporting a load that was 15% bw. The strength-training protocol consisted of 12 weeks of training, five days/week with 4 sets of 10 jumps in water with 1 min rest between sets, supporting a load that was a 50% bw. RESULTS At 28 days, the alloxan animals exhibited higher insulin resistance as measured by the disappearance of glucose serum (% Kitt/min) during the ITT. At 120 days, the sedentary alloxan animals showed higher FFA values than continuous and intermittent training alloxan. In addition, the alloxan animals that underwent intermittent and strength training showed lower FFA values compared to the corresponding controls. The continuous training protocol was less effective than the strength training protocol for reducing the levels of total cholesterol in the alloxan animals. Serum total lipid values revealed that intermittent training increased serum levels in alloxan animals CONCLUSION Thus, it was concluded that physical training at different intensities of effort is of great importance in attenuation and control of changes in the lipid metabolism in alloxan animals.
Collapse
Affiliation(s)
- Carla Ribeiro
- Institute of Biosciences Physical Education Department, São Paulo State University – (Universidade Estadual Paulista- UNESP), Av: 24-A, 1515 Bela Vista, Rio Claro – São Paulo, CEP: 13506-900, Brazil
| | - Lucieli Teresa Cambri
- Institute of Biosciences Physical Education Department, São Paulo State University – (Universidade Estadual Paulista- UNESP), Av: 24-A, 1515 Bela Vista, Rio Claro – São Paulo, CEP: 13506-900, Brazil
| | - Rodrigo Augusto Dalia
- Institute of Biosciences Physical Education Department, São Paulo State University – (Universidade Estadual Paulista- UNESP), Av: 24-A, 1515 Bela Vista, Rio Claro – São Paulo, CEP: 13506-900, Brazil
| | - Michel Barbosa de Araújo
- Institute of Biosciences Physical Education Department, São Paulo State University – (Universidade Estadual Paulista- UNESP), Av: 24-A, 1515 Bela Vista, Rio Claro – São Paulo, CEP: 13506-900, Brazil
| | - José Diego Botezelli
- Institute of Biosciences Physical Education Department, São Paulo State University – (Universidade Estadual Paulista- UNESP), Av: 24-A, 1515 Bela Vista, Rio Claro – São Paulo, CEP: 13506-900, Brazil
| | - Amanda Christine da Silva Sponton
- Institute of Biosciences Physical Education Department, São Paulo State University – (Universidade Estadual Paulista- UNESP), Av: 24-A, 1515 Bela Vista, Rio Claro – São Paulo, CEP: 13506-900, Brazil
| | - Maria Alice Rostom de Mello
- Institute of Biosciences Physical Education Department, São Paulo State University – (Universidade Estadual Paulista- UNESP), Av: 24-A, 1515 Bela Vista, Rio Claro – São Paulo, CEP: 13506-900, Brazil
| |
Collapse
|
159
|
Six weeks of aerobic training improves VO2max and MLSS but does not improve the time to fatigue at the MLSS. Eur J Appl Physiol 2012; 113:965-73. [DOI: 10.1007/s00421-012-2501-y] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2012] [Accepted: 09/14/2012] [Indexed: 10/27/2022]
|
160
|
Moxnes JF, Sandbakk Ø. The kinetics of lactate production and removal during whole-body exercise. Theor Biol Med Model 2012; 9:7. [PMID: 22413898 PMCID: PMC3337802 DOI: 10.1186/1742-4682-9-7] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2011] [Accepted: 03/13/2012] [Indexed: 11/02/2022] Open
Abstract
BACKGROUND Based on a literature review, the current study aimed to construct mathematical models of lactate production and removal in both muscles and blood during steady state and at varying intensities during whole-body exercise. In order to experimentally test the models in dynamic situations, a cross-country skier performed laboratory tests while treadmill roller skiing, from where work rate, aerobic power and blood lactate concentration were measured. A two-compartment simulation model for blood lactate production and removal was constructed. RESULTS The simulated and experimental data differed less than 0.5 mmol/L both during steady state and varying sub-maximal intensities. However, the simulation model for lactate removal after high exercise intensities seems to require further examination. CONCLUSIONS Overall, the simulation models of lactate production and removal provide useful insight into the parameters that affect blood lactate response, and specifically how blood lactate concentration during practical training and testing in dynamical situations should be interpreted.
Collapse
Affiliation(s)
- John F Moxnes
- Department for Protection Norwegian Defence Research Establishment, P.O. Box 25, 2007 Kjeller, Norway
| | - Øyvind Sandbakk
- Department of Human Movement Science, Norwegian University of science and Technology, 7491 Trondheim, Norway
| |
Collapse
|
161
|
Grossl T, De Lucas RD, De Souza KM, Antonacci Guglielmo LG. Maximal lactate steady-state and anaerobic thresholds from different methods in cyclists. Eur J Sport Sci 2012. [DOI: 10.1080/17461391.2010.551417] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
|
162
|
Leti T, Mendelson M, Laplaud D, Flore P. Prediction of maximal lactate steady state in runners with an incremental test on the field. J Sports Sci 2012; 30:609-16. [DOI: 10.1080/02640414.2012.660187] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
|
163
|
Baragli P, Vitale V, Sgorbini M, Sighieri C. Influence of sampling time in the assessment of anaerobic threshold in horses. COMPARATIVE EXERCISE PHYSIOLOGY 2012. [DOI: 10.3920/cep12010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Validity and reproducibility of anaerobic threshold (VLA4) is still matter for debate. Factors influencing blood lactate concentration, including blood collection procedure, are critical. This study aimed to evaluate influence of blood sampling times on VLA4 computing in two different horse breeds. Five Standardbreds and six Haflingers were included in this study. All the horses performed a standardised exercise test on treadmill (SET). An automatic collection device was employed to obtain blood samples every 60 seconds, in order to standardise sampling time. VLA4 was computed using the lactate data at the end of each step of the SET, and the corresponding velocity (VLA40min). The detection was then repeated for the concentrations at 1 (VLA41min), 2 (VLA42min) and 3 min (VLA43min) after the end of the 3rd step maintaining constant plasma lactate concentration of the first and the second step. VLA4 resulted increased with the VLA40min, while with the VLA41min, VLA42minand VLA43minthe value of the VLA4 decreased progressively. Difference, expressed as a percentage, between VLA40minand VLA43minmean values was 16.8 and 16.6%, for Standardbred and Haflinger horses, respectively. Hence, blood samples drawn within a time frame of 3 min after the end of the SET seem to induce changes when computing of VLA4. The results suggest to carefully pay attention in standardise sampling time, collecting blood in a time frame of two minutes, one minute after the end of exercise.
Collapse
Affiliation(s)
- P. Baragli
- Department of Physiological Sciences, University of Pisa, viale delle Piagge 2, 56124 Pisa, Italy
| | - V. Vitale
- Department of Physiological Sciences, University of Pisa, viale delle Piagge 2, 56124 Pisa, Italy
| | - M. Sgorbini
- Department of Veterinary Clinics, University of Pisa, via Livornese snc, 50122 Pisa, Italy
| | - C. Sighieri
- Department of Physiological Sciences, University of Pisa, viale delle Piagge 2, 56124 Pisa, Italy
| |
Collapse
|
164
|
Blood lactate concentration at the maximal lactate steady state is not dependent on endurance capacity in healthy recreationally trained individuals. Eur J Appl Physiol 2011; 112:3079-86. [PMID: 22194004 DOI: 10.1007/s00421-011-2283-7] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2010] [Accepted: 12/09/2011] [Indexed: 10/14/2022]
Abstract
The aim of the study was to investigate the independent relationship between maximal lactate steady state (MLSS), blood lactate concentration [La] and exercise performance as reported frequently. Sixty-two subjects with a wide range of endurance performance (MLSS power output 199 ± 55 W; range: 100-302 W) were tested on an electronically braked cycle ergometer. One-min incremental exercise tests were conducted to determine maximal variables as well as the respiratory compensation point (RCP) and the second lactate turn point (LTP2). Several continuous exercise tests were performed to determine the MLSS. Subjects were divided into three clusters of exercise performance. Dietary control was employed throughout all testing. No significant correlation was found between MLSS [La] and power output at MLSS. Additionally, the three clusters of subjects with different endurance performance levels based on power output at MLSS showed no significant difference for MLSS [La]. MLSS [La] was not significantly different between men and women (average of 4.80 ± 1.50 vs. 5.22 ± 1.52 mmol l(-1)). MLSS [La] was significantly related to [La] at RCP, LTP2 and at maximal power. The results of this study support previous findings that MLSS [La] is independent of endurance performance. Additionally, MLSS [La] was not influenced by sex. Correlations found between MLSS [La] and [La] at maximal power and at designated anaerobic thresholds indicate only an association of [La] response during incremental and MLSS exercise when utilizing cycle ergometry.
Collapse
|
165
|
Botezelli JD, Cambri LT, Ghezzi AC, Dalia RA, M Scariot PP, Ribeiro C, Voltarelli FA, Mello MAR. Different exercise protocols improve metabolic syndrome markers, tissue triglycerides content and antioxidant status in rats. Diabetol Metab Syndr 2011; 3:35. [PMID: 22182600 PMCID: PMC3296599 DOI: 10.1186/1758-5996-3-35] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/22/2011] [Accepted: 12/19/2011] [Indexed: 01/24/2023] Open
Abstract
BACKGROUND An increase in the prevalence of obesity entails great expenditure for governments. Physical exercise is a powerful tool in the combat against obesity and obesity-associated diseases. This study sought to determine the effect of three different exercise protocols on metabolic syndrome and lipid peroxidation markers and the activity of antioxidant enzymes in adult Wistar rats (120 days old). METHODS Animals were randomly divided into four groups: the control (C) group was kept sedentary throughout the study; the aerobic group (A) swam1 h per day, 5 days per week, at 80% lactate threshold intensity; the strength group (S) performed strength training with four series of 10 jumps, 5 days per week; and the Concurrent group (AS) was trained using the aerobic protocol three days per week and the strength protocol two days per week. RESULTS Groups A and S exhibited a reduction in body weight compared to group C. All exercised animals showed a reduction in triglyceride concentrations in fatty tissues and the liver. Exercised animals also exhibited a reduction in lipid peroxidation markers (TBARS) and an increase in serum superoxide dismutase activity. Animals in group A had increased levels of liver catalase and superoxide dismutase activities. CONCLUSIONS We concluded that all physical activity protocols improved the antioxidant systems of the animals and decreased the storage of triglycerides in the investigated tissues.
Collapse
Affiliation(s)
- José D Botezelli
- Physical Education Department, São Paulo State University - UNESP, 24-A Av. 1515, Rio Claro, Zip Code:13607-331, Brazil
| | - Lucieli T Cambri
- Physical Education Department, São Paulo State University - UNESP, 24-A Av. 1515, Rio Claro, Zip Code:13607-331, Brazil
| | - Ana C Ghezzi
- Physical Education Department, São Paulo State University - UNESP, 24-A Av. 1515, Rio Claro, Zip Code:13607-331, Brazil
| | - Rodrigo A Dalia
- Physical Education Department, São Paulo State University - UNESP, 24-A Av. 1515, Rio Claro, Zip Code:13607-331, Brazil
| | - Pedro P M Scariot
- Physical Education Department, São Paulo State University - UNESP, 24-A Av. 1515, Rio Claro, Zip Code:13607-331, Brazil
| | - Carla Ribeiro
- Physical Education Department, São Paulo State University - UNESP, 24-A Av. 1515, Rio Claro, Zip Code:13607-331, Brazil
| | - Fabrício A Voltarelli
- Physical Education Department, Mato Grosso Federal University-UFMT, Brasilia Av. 1200, Cuiabá, Zip Code: 78550-000, Brazil
| | - Maria AR Mello
- Physical Education Department, São Paulo State University - UNESP, 24-A Av. 1515, Rio Claro, Zip Code:13607-331, Brazil
| |
Collapse
|
166
|
Maximal lactate steady state in swimming rats by a body density-related method of workload quantification. COMPARATIVE EXERCISE PHYSIOLOGY 2011. [DOI: 10.1017/s1755254011000134] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
|
167
|
Assessment of aerobic capacity during swimming exercise in ob/ob mice. Cell Biochem Funct 2011; 29:666-72. [DOI: 10.1002/cbf.1803] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2010] [Revised: 04/29/2011] [Accepted: 08/13/2011] [Indexed: 11/07/2022]
|
168
|
Perret C, Labruyère R, Mueller G, Strupler M. Correlation of heart rate at lactate minimum and maximal lactate steady state in wheelchair-racing athletes. Spinal Cord 2011; 50:33-6. [DOI: 10.1038/sc.2011.97] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
|
169
|
Abstract
The present study tested the hypothesis that the exercise protocol (continuous vs. intermittent) would affect the physiological response and the perception of effort during aquatic cycling. Each protocol was divided on four stages. Heart rate, arterial blood pressure, blood lactate concentration, central and peripheral rate of perceived exertion were collected in both protocols in aquatic cycling in 10 women (values are mean ± SD): age=32.8 ± 4.8 years; height=1.62 ± 0.05 cm; body mass=61.60 ± 5.19 kg; estimated body fat=27.13 ± 4.92%. Protocols were compared through two way ANOVA with Scheffé’s post-hoc test and the test of Mann- Whitney for rate of perceived exertion with α=0.05. No systematic and consistent differences in heart rate, arterial blood pressure, double product and blood lactate concentration were found between protocols. On the other hand, central rate of perceived exertion was significantly higher at stage four during continuous protocol compared with intermittent protocol (p=0.01), while the peripheral rate of perceived exertion presented higher values at stages three (p=0.02) and four (p=0.00) in the continuous protocol when compared to the results found in intermittent protocol. These findings suggest that although the aquatic cycling induces similar physiologic demands in both protocols, the rate of perceived exertion may vary according to the continuous vs. intermittent nature of the exercise.
Collapse
|
170
|
Soares E, Lima W, Machado R, Carneiro C, Silva M, Rodrigues M, De Castro U, Santos R, Campagnole-Santos M, Alzamora A. Cardiac and renal effects induced by different exercise workloads in renovascular hypertensive rats. Braz J Med Biol Res 2011; 44:573-82. [DOI: 10.1590/s0100-879x2011007500049] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2010] [Accepted: 04/06/2011] [Indexed: 11/22/2022] Open
Affiliation(s)
- E.R. Soares
- Universidade Federal de Ouro Preto, Brasil; Instituto Nacional de Ciência e Tecnologia em Inovação Nano-Biofarmacêutica, Brasil
| | - W.G. Lima
- Universidade Federal de Ouro Preto; Universidade Federal de Ouro Preto, Brasil; Instituto Nacional de Ciência e Tecnologia em Inovação Nano-Biofarmacêutica, Brasil
| | - R.P. Machado
- Universidade Federal de Ouro Preto; Universidade Federal de Ouro Preto, Brasil; Instituto Nacional de Ciência e Tecnologia em Inovação Nano-Biofarmacêutica, Brasil
| | | | - M.E. Silva
- Universidade Federal de Ouro Preto, Brasil; Instituto Nacional de Ciência e Tecnologia em Inovação Nano-Biofarmacêutica, Brasil
| | | | - U.G. De Castro
- Universidade Federal de Ouro Preto, Brasil; Instituto Nacional de Ciência e Tecnologia em Inovação Nano-Biofarmacêutica, Brasil
| | - R.A.S. Santos
- Universidade Federal de Minas Gerais, Brasil; Instituto Nacional de Ciência e Tecnologia em Inovação Nano-Biofarmacêutica, Brasil
| | - M.J. Campagnole-Santos
- Universidade Federal de Minas Gerais, Brasil; Instituto Nacional de Ciência e Tecnologia em Inovação Nano-Biofarmacêutica, Brasil
| | - A.C. Alzamora
- Universidade Federal de Ouro Preto; Universidade Federal de Ouro Preto, Brasil; Instituto Nacional de Ciência e Tecnologia em Inovação Nano-Biofarmacêutica, Brasil
| |
Collapse
|
171
|
Legaz-Arrese A, Munguía-Izquierdo D, Carranza-García LE, Reverter-Masía J, Torres-Dávila CG, Medina-Rodríguez RE. The validity of incremental exercise testing in discriminating of physiological profiles in elite runners. ACTA ACUST UNITED AC 2011; 98:147-56. [PMID: 21616773 DOI: 10.1556/aphysiol.98.2011.2.6] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
The goal of this study was to determine whether traditional ergoespirometric incremental exercise testing carried out to the point of exhaustion could be useful in distinguishing the physiological profiles of elite runners that compete in races that lasted about 8 minutes versus those that lasted about 2 hours. Ten male marathon runners (performance time: 2:12:04, coefficient of variation (CV) = 2.33%) and 8 male 3000 m steeplechase runners (performance time: 8:37.83, CV = 2.12%) performed an incremental test on the treadmill (starting speed 10 km·h-1; increments, 2 km·h-1; increment duration, 3 min to exhaustion). Heart rate (HR), VO2, and lactate concentrations were measured at the end of each exercise level. At maximal effort, there were no differences between the groups regarding VO2max and maximal HR; however, the workload time, vVO2max and peak treadmill velocity were significantly higher in the 3000 m steeplechase group (p<0.05). At submaximal effort, there were no significant differences between groups for VO2 (ml·kg-1·min-1), HR, or lactate. Our results show that this type of testing was not sufficient for discriminating the physiological profiles of elite runners who competed in middle-distance versus long-distance events (e.g. in the marathon and the 3000 m steeplechase).
Collapse
|
172
|
Machado MV, Júnior OA, Marques AC, Colantonio E, Cyrino ES, De Mello MT. Effect of 12 weeks of training on critical velocity and maximal lactate steady state in swimmers. Eur J Sport Sci 2011. [DOI: 10.1080/17461391.2010.499973] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
|
173
|
Lorenzo S, Minson CT, Babb TG, Halliwill JR. Lactate threshold predicting time-trial performance: impact of heat and acclimation. J Appl Physiol (1985) 2011; 111:221-7. [PMID: 21527667 DOI: 10.1152/japplphysiol.00334.2011] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The relationship between exercise performance and lactate and ventilatory thresholds under two distinct environmental conditions is unknown. We examined the relationships between six lactate threshold methods (blood- and ventilation-based) and exercise performance in cyclists in hot and cool environments. Twelve cyclists performed a lactate threshold test, a maximal O(2) uptake (Vo(2max)) test, and a 1-h time trial in hot (38°C) and cool (13°C) conditions, before and after heat acclimation. Eight control subjects completed the same tests before and after 10 days of identical exercise in a cool environment. The highest correlations were observed with the blood-based lactate indexes; however, even the indirect ventilation-based indexes were well correlated with mean power during the time trial. Averaged bias was 15.4 ± 3.6 W higher for the ventilation- than the blood-based measures (P < 0.05). The bias of blood-based measures in the hot condition was increased: the time trial was overestimated by 37.7 ± 3.6 W compared with only 24.1 ± 3.2 W in the cool condition (P < 0.05). Acclimation had no effect on the bias of the blood-based indexes (P = 0.51) but exacerbated the overestimation by some ventilation-based indexes by an additional 34.5 ± 14.1 W (P < 0.05). Blood-based methods to determine lactate threshold show less bias and smaller variance than ventilation-based methods when predicting time-trial performance in cool environments. Of the blood-based methods, the inflection point between steady-state lactate and rising lactate (INFL) was the best method to predict time-trial performance. Lastly, in the hot condition, ventilation-based predictions are less accurate after heat acclimation, while blood-based predictions remain valid in both environments after heat acclimation.
Collapse
Affiliation(s)
- Santiago Lorenzo
- Department of Human Physiology, University of Oregon, Eugene, OR 97403-1240, USA
| | | | | | | |
Collapse
|
174
|
Da Silva ASR, Pauli JR, Ropelle ER, Oliveira AG, Cintra DE, De Souza CT, Velloso LA, Carvalheira JBC, Saad MJA. Exercise intensity, inflammatory signaling, and insulin resistance in obese rats. Med Sci Sports Exerc 2010; 42:2180-8. [PMID: 20473230 DOI: 10.1249/mss.0b013e3181e45d08] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
PURPOSE To evaluate the effects of intensity of exercise on insulin resistance and the expression of inflammatory proteins in the skeletal muscle of diet-induced obese (DIO) rats after a single bout of exercise. METHODS In the first exercise protocol, the rats swam for two 3-h bouts, separated by a 45-min rest period (with 6 h in duration--O + EXE), and in the second protocol, the rats were exercised with 45 min of swimming at 70% of the maximal lactate steady state--SS (DIO + MLSS). RESULTS Our data demonstrated that both protocols of exercise increased insulin sensitivity and increased insulin-stimulated tyrosine phosphorylation of insulin receptor and insulin receptor substrate 1 and serine phosphorylation of protein kinase B in the muscle of DIO rats by the same magnitude. In parallel, both exercise protocols also reduced protein tyrosine phosphatase 1B activity and insulin receptor substrate 1 serine phosphorylation, with concomitant reduction in c-jun N-terminal kinase and IJB kinase activities in the muscle of DIO rats in a similar fashion. CONCLUSIONS Thus, our data demonstrate that either exercise protocols with low intensity and high volume or exercise with moderate intensity and low volume represents different strategies to restore insulin sensitivity with the same efficacy.
Collapse
Affiliation(s)
- Adelino S R Da Silva
- Department of Internal Medicine, Faculty of Medical Sciences State University of Campinas-UNICAMP, Campinas, São Paulo, Brazil
| | | | | | | | | | | | | | | | | |
Collapse
|
175
|
Cambri LT, Dalia RA, Ribeiro C, Rostom de Mello MA. Aerobic capacity of rats recovered from fetal malnutrition with a fructose-rich diet. Appl Physiol Nutr Metab 2010; 35:490-7. [PMID: 20725115 DOI: 10.1139/h10-034] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The objective of this study was to analyze the aerobic capacity, through the maximal lactate steady-state (MLSS) protocol, of rats subjected to fetal protein malnutrition and recovered with a fructose-rich diet. Pregnant adult Wistar rats that were fed a balanced (17% protein) diet or a low-protein (6% protein) diet were used. After birth, the offspring were distributed into groups according to diet until 60 days of age: balanced (B), balanced diet during the whole experimental period; balanced-fructose (BF), balanced diet until birth and fructose-rich diet (60% fructose) until 60 days; low protein-balanced (LB), low-protein diet until birth and balanced diet until 60 days; and low protein-fructose (LF), low protein diet until birth and fructose-rich diet until 60 days. It was verified that the fructose-rich diet reduced body growth, mainly in the BF group. There was no difference among the groups in the load corresponding to the MLSS (B, 7.5+/-0.5%; BF, 7.4+/-0.6%; LB, 7.7+/-0.4%; and LF, 7.7+/-0.6% relative to body weight). However, the BF group presented higher blood lactate concentrations (4.8+/-0.9 mmol.L(-1)) at 25 min in the load corresponding to the MLSS (B, 3.2+/-0.9 mmol.L(-1); LB, 3.4+/-0.9 mmol.L(-1); and LF, 3.2+/-1.0 mmol.L(-1)). Taken together, these results indicate that the ability of young rats to perform exercise was not altered by intrauterine malnutrition or a fructose-rich diet, although the high fructose intake after the balanced diet in utero increased blood lactate during swimming exercises in rats.
Collapse
Affiliation(s)
- Lucieli Teresa Cambri
- Department of Physical Education, São Paulo State University (UNESP), Rio Claro-SP, Brazil.
| | | | | | | |
Collapse
|
176
|
de Oliveira CAM, Paiva MF, Mota CAS, Ribeiro C, de Almeida Leme JAC, Luciano E, de Mello MAR. Exercise at anaerobic threshold intensity and insulin secretion by isolated pancreatic islets of rats. Islets 2010; 2:240-6. [PMID: 21099318 PMCID: PMC3322538 DOI: 10.4161/isl.2.4.12266] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/28/2010] [Revised: 05/01/2010] [Accepted: 05/03/2010] [Indexed: 11/19/2022] Open
Abstract
To evaluate the effect of acute exercise and exercise training at the anaerobic threshold (AT) intensity on aerobic conditioning and insulin secretion by pancreatic islets, adult male Wistar rats were submitted to the lactate minimum test (LMT) for AT determination. Half of the animals were submitted to swimming exercise training (trained), 1 h/day, 5 days/week during 8 weeks, with an overload equivalent to the AT. The other half was kept sedentary (sedentary). At the end of the experimental period, the rats were submitted to an oral glucose tolerance test and to another LMT. Then, the animals were sacrificed at rest or immediately after 20 minutes of swimming exercise at the AT intensity for pancreatic islets isolation. At the end of the experiment mean workload (% bw) at AT was higher and blood lactate concentration (mmol/L) was lower in the trained than in the control group. Rats trained at the AT intensity showed no alteration in the areas under blood glucose and insulin during OGTT test. Islet insulin content of trained rats was higher than in the sedentary rats while islet glucose uptake did not differ among the groups. The static insulin secretion in response to the high glucose concentration (16.7 mM) of the sedentary group at rest was lower than the sedentary group submitted to the acute exercise and the inverse was observed in relation to the trained groups. Physical training at the AT intensity improved the aerobic condition and altered insulin secretory pattern by pancreatic islets.
Collapse
Affiliation(s)
| | | | | | - Carla Ribeiro
- Department of Physical Education; Unesp; São Paulo, Brazil
| | | | - Eliete Luciano
- Department of Physical Education; Unesp; São Paulo, Brazil
| | | |
Collapse
|
177
|
Romero MR, Ahumada F, Garay F, Baruzzi AM. Amperometric Biosensor for Direct Blood Lactate Detection. Anal Chem 2010; 82:5568-72. [DOI: 10.1021/ac1004426] [Citation(s) in RCA: 87] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Marcelo Ricardo Romero
- INFIQC, Departimento de Físico Química, Faculdad de Ciencias Químicas, UNC, Pab. Argentina, Ala 1, 2° piso, Ciudad Universitaria, 5000 Córdoba, Argentina
| | - Facundo Ahumada
- INFIQC, Departimento de Físico Química, Faculdad de Ciencias Químicas, UNC, Pab. Argentina, Ala 1, 2° piso, Ciudad Universitaria, 5000 Córdoba, Argentina
| | - Fernando Garay
- INFIQC, Departimento de Físico Química, Faculdad de Ciencias Químicas, UNC, Pab. Argentina, Ala 1, 2° piso, Ciudad Universitaria, 5000 Córdoba, Argentina
| | - Ana M. Baruzzi
- INFIQC, Departimento de Físico Química, Faculdad de Ciencias Químicas, UNC, Pab. Argentina, Ala 1, 2° piso, Ciudad Universitaria, 5000 Córdoba, Argentina
| |
Collapse
|
178
|
Greco CC, Oliveira MFMD, Caputo F, Pelarigo JG, Denadai BS. Efeitos do desempenho aeróbio na máxima fase estável de lactato sanguíneo determinada em protocolo intermitente na natação. REV BRAS MED ESPORTE 2010. [DOI: 10.1590/s1517-86922010000200011] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Atletas de endurance frequentemente realizam exercícios intermitentes, com o objetivo de aumentar a intensidade do treinamento. Um índice bastante importante na avaliação desses atletas é a máxima fase estável de lactato sanguíneo (MLSS), que em geral é determinada com um protocolo contínuo. No entanto, as pausas existentes durante o exercício intermitente podem modificar as condições metabólicas dele. O objetivo deste estudo foi comparar a intensidade de nado correspondente à MLSS determinada de forma contínua (MLSSc) e intermitente (MLSSi) em atletas com diferentes níveis de rendimento aeróbio. Doze nadadores (22 ± 8 anos; 69,9 ± 7,63kg e 1,76 ± 0,07m) e oito triatletas do gênero masculino (22 ± 9 anos; 69,5 ± 10,4kg e 1,76 ± 0,13m), realizaram os seguintes testes em diferentes dias em uma piscina de 25 m: 1) teste máximo na distância de 400m (v400); 2) duas a quatro repetições com duração de 30 min em diferentes intensidades, para a determinação da MLSSc, e; 4) duas a quatro tentativas de 12 x 150s com intervalo de 30s (5:1) em diferentes intensidades, para a determinação da MLSSi. Os nadadores apresentaram maiores valores em relação aos triatletas da v400 (1,38 ± 0,05 e 1,26 ± 0,06m.s-1, respectivamente), MLSSc (1,23 ± 0,05 e 1,08 ± 0,04m.s-1, respectivamente) e MLSSi (1,26 ± 0,05 e 1,11 ± 0,05m.s-1, respectivamente). No entanto, a diferença percentual entre a MLSSc e a MLSSi foi estatisticamente similar entre os grupos (3%). Não houve diferença significante entre a concentração de lactato na MLSSc e na MLSSi nos dois grupos. Com base nesses resultados, pode-se concluir que o exercício intervalado utilizado permite um aumento na intensidade do exercício correspondente a MLSS, sem modificação na concentração de lactato, independente do nível de desempenho aeróbio.
Collapse
|
179
|
Ferreira JCB, Bacurau AV, Bueno CR, Cunha TC, Tanaka LY, Jardim MA, Ramires PR, Brum PC. Aerobic exercise training improves Ca2+ handling and redox status of skeletal muscle in mice. Exp Biol Med (Maywood) 2010; 235:497-505. [DOI: 10.1258/ebm.2009.009165] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Exercise training is known to promote relevant changes in the properties of skeletal muscle contractility toward powerful fibers. However, there are few studies showing the effect of a well-established exercise training protocol on Ca2+ handling and redox status in skeletal muscles with different fiber-type compositions. We have previously standardized a valid and reliable protocol to improve endurance exercise capacity in mice based on maximal lactate steady-state workload (MLSSw). The aim of this study was to investigate the effect of exercise training, performed at MLSSw, on the skeletal muscle Ca2+ handling-related protein levels and cellular redox status in soleus and plantaris. Male C57BL/6J mice performed treadmill training at MLSSw over a period of eight weeks. Muscle fiber-typing was determined by myosin ATPase histochemistry, citrate synthase activity by spectrophotometric assay, Ca2+ handling-related protein levels by Western blot and reduced to oxidized glutathione ratio (GSH:GSSG) by high-performance liquid chromatography. Trained mice displayed higher running performance and citrate synthase activity compared with untrained mice. Improved running performance in trained mice was paralleled by fast-to-slow fiber-type shift and increased capillary density in both plantaris and soleus. Exercise training increased dihydropyridine receptor (DHPR) α2 subunit, ryanodine receptor and Na+/Ca2+ exchanger levels in plantaris and soleus. Moreover, exercise training elevated DHPR β1 subunit and sarcoplasmic reticulum Ca2+-ATPase (SERCA) 1 levels in plantaris and SERCA2 levels in soleus of trained mice. Skeletal muscle GSH content and GSH:GSSG ratio was increased in plantaris and soleus of trained mice. Taken together, our findings indicate that MLSSw exercise-induced better running performance is, in part, due to increased levels of proteins involved in skeletal muscle Ca2+ handling, whereas this response is partially dependent on specificity of skeletal muscle fiber-type composition. Finally, we demonstrated an augmented cellular redox status and GSH antioxidant capacity in trained mice.
Collapse
Affiliation(s)
- Julio C B Ferreira
- School of Physical Education and Sport, University of Sao Paulo (USP), São Paulo 05508-900, Brazil
| | - Aline V Bacurau
- School of Physical Education and Sport, University of Sao Paulo (USP), São Paulo 05508-900, Brazil
| | - Carlos R Bueno
- School of Physical Education and Sport, University of Sao Paulo (USP), São Paulo 05508-900, Brazil
| | - Telma C Cunha
- School of Physical Education and Sport, University of Sao Paulo (USP), São Paulo 05508-900, Brazil
| | - Leonardo Y Tanaka
- School of Physical Education and Sport, University of Sao Paulo (USP), São Paulo 05508-900, Brazil
| | - Maira A Jardim
- School of Physical Education and Sport, University of Sao Paulo (USP), São Paulo 05508-900, Brazil
| | - Paulo R Ramires
- School of Physical Education and Sport, University of Sao Paulo (USP), São Paulo 05508-900, Brazil
| | - Patricia C Brum
- School of Physical Education and Sport, University of Sao Paulo (USP), São Paulo 05508-900, Brazil
| |
Collapse
|
180
|
Acute Carbohydrate Ingestion Affects Lactate Response in Highly Trained Swimmers. Int J Sports Physiol Perform 2010; 5:42-54. [DOI: 10.1123/ijspp.5.1.42] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Purpose:Effects of acute carbohydrate ingestion on blood lactate (BLa) response to graded exercise was examined in highly trained male and female swimmers.Methods:Twenty-three swimmers performed the United States Swimming Lactate Protocol, a graded interval test (5 × 200 on 5 min), following ingestion of carbohydrate sports drink (CHO) and placebo (PLA).Results:There was no difference in heart rate (P = .55), swim velocity (P = .95), or ratings of perceived exertion (P = .58) between beverages. There was a signifcant main effect for gender (P = .002) on BLa during all swim stages and recovery. In females, BLa was 27% to 50% higher for CHO during the first (P = .009) and second (P = .04) swim stages. Predicted BLa at selected swim velocity was higher (P = .048) for CHO versus PLA in females at 1.27 m·s−1 and higher (P < .02) for men at 1.4 m·s−1. Mean (±SD) BLa was significantly (P = .004) greater for CHO (2.7 ± 1.2) compared with PLA (2.0 ± 1.1 mmol·L−1) during the second test stage and when normalized relative to velocity (P = .004). Peak BLa after the final swim (9.6 ± 3.1 vs. 9.0 ± 3.2 mmol·L−1, P = .36) was not different between CHO and PLA.Conclusions:Acute CHO ingestion alters the BLa: swim velocity relationship during moderate intensity swims of an incremental swim test, particularly for females. Therefore, pretest beverage ingestion should be standardized during the administration of BLa testing to prevent potential erroneous interpretations regarding athlete’s training status.
Collapse
|
181
|
Oliveira ADSC, Caputo F, Gonçalves M, Denadai BS. Heavy-intensity aerobic exercise affects the isokinetic torque and functional but not conventional hamstrings:quadriceps ratios. J Electromyogr Kinesiol 2009; 19:1079-84. [DOI: 10.1016/j.jelekin.2008.10.005] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2008] [Revised: 10/21/2008] [Accepted: 10/21/2008] [Indexed: 10/21/2022] Open
|
182
|
Ellis D, Simmons C, Miller BF. Sodium lactate infusion during a cycling time-trial does not increase lactate concentration or decrease performance. Eur J Sport Sci 2009. [DOI: 10.1080/17461390903009158] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
|
183
|
|
184
|
Tolfrey K, Hansen SA, Dutton K, McKee T, Jones AM. Physiological correlates of 2-mile run performance as determined using a novel on-demand treadmill. Appl Physiol Nutr Metab 2009; 34:763-72. [PMID: 19767813 DOI: 10.1139/h09-069] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
The purpose of this study was to assess the reproducibility of an on-demand motorised treadmill to measure 2-mile (3.2 km) race performance and to examine the physiological variables that best predict this free-running performance in active men. Twelve men (mean (SD): age, 28 (9) years; stature, 1.79 (0.05) m; body mass, 72 (9) kg) completed the study in which maximum oxygen uptake (VO2 max), running economy, and running speedin the abstract section. They appear in the rest of the paper.), running economy, and running speed at VO2 max (vVO2 max), lactate threshold (vLT), and 4 mmol.L-1 fixed blood lactate concentration (v4) were measured. Subsequently, the maximal lactate steady state (MLSS) was identified using a series of 30-min treadmill runs. Finally, each participant completed a 2-mile running performance trial on 2 separate occasions, using an on-demand treadmill that adjusts belt speed according to the participant's position on the moving belt. The average 2-mile run speed was 15.7 (SD, 1.9) km.h-1, with small individual differences between repeat-performance trials (intraclass correlation coefficient = 0.99, 95% CI 0.953 to 0.996; standard error of measurement as coefficient of variation = 1.5%, 95% CI 1.0% to 2.5%). Bivariate regression analyses identified VO2 max, vVO2 max, VO2 (mL.kg-1.min-1) at MLSS, vLT, v4, and velocity at MLSS (vMLSS) as the strongest individual predictor variables (r2 = 0.69 to 0.87; standard error of the estimate = 1.08 to 0.72 km.h-1) for 2-mile running performance. The vLT and vMLSS explained 85% and 87% of the variance in running performance, respectively, suggesting that there is considerable shared variance between these parameters. In conclusion, the on-demand treadmill system provided a reliable measure of distance running performance. Both vLT and vMLSS were strong predictors of 2-mile running performance, with vMLSS explaining marginally more of the variance.
Collapse
Affiliation(s)
- Keith Tolfrey
- School of Sport, Exercise and Health Sciences, Loughborough University, Loughborough, LE11 3TU, UK.
| | | | | | | | | |
Collapse
|
185
|
Araújo MBD, Manchado-Gobatto FDB, Voltarelli FA, Ribeiro C, Mota CSDA, Gobatto CA, Mello MARD. Efeitos do treinamento de corrida em diferentes intensidades sobre a capacidade aeróbia e produção de lactato pelo músculo de ratos Wistar. REV BRAS MED ESPORTE 2009. [DOI: 10.1590/s1517-86922009000600009] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
São raros os estudos que associam indicadores de capacidade aeróbia e os substratos produzidos pelo metabolismo muscular em ratos. Dessa forma, o objetivo do presente estudo foi verificar o efeito do treinamento de corrida em duas diferentes intensidades sobre a capacidade aeróbia e a produção de lactato pelo músculo sóleo isolado de ratos. Ratos Wistar (90 dias) tiveram a transição metabólica aeróbio-anaeróbia determinada pelo teste de máxima fase estável de lactato (MFEL). Em seguida, os ratos foram treinados 40 minutos/dia, cinco dias/semana, na velocidade equivalente à MFEL (TT) ou 5% superior a essa (TS), por oito semanas. Como controles foram usados ratos mantidos sedentários (S). Ao final, todos os animais foram sacrificados para análise da produção de lactato pelo músculo sóleo isolado. No inicio do experimento, a maior parte dos animais obteve a MFEL na velocidade de 25m/min à concentração de 4,38 ± 0,22mmol/L sanguínea de lactato. Ao final do experimento, a maior parte dos ratos treinados na TT apresentou MFEL na velocidade de 25m/min, à concentração sanguínea de lactato 3,10 ± 0,27mmol/L. A maioria dos treinados TS teve MFEL na velocidade de 25m/min à concentração sanguínea de lactado de 3,36 ± 0,62mmol/L. Os sedentários mostraram a MFEL na velocidade de 20m/min à concentração sanguínea de lactato de 4,83 ± 0,67mmol/L. A produção de lactato (μmol/g.h) pelo músculo sóleo isolado foi menor no grupo TS (3,83 ± 0,62) do que nos demais (S 4,31 ± 0,58 e TT 4,71 ± 0,39). A partir dos resultados obtidos no presente estudo, pode-se concluir que o treinamento aeróbio evitou a deterioração do condicionamento aeróbio imposta pelo avanço da idade e que o treinamento físico na intensidade superior à MFEL reduziu a produção muscular de lactato.
Collapse
|
186
|
Standards for the use of cardiopulmonary exercise testing for the functional evaluation of cardiac patients: a report from the Exercise Physiology Section of the European Association for Cardiovascular Prevention and Rehabilitation. ACTA ACUST UNITED AC 2009; 16:249-67. [PMID: 19440156 DOI: 10.1097/hjr.0b013e32832914c8] [Citation(s) in RCA: 255] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Cardiopulmonary exercise testing (CPET) is a methodology that has profoundly affected the approach to patients' functional evaluation, linking performance and physiological parameters to the underlying metabolic substratum and providing highly reproducible exercise capacity descriptors. This study provides professionals with an up-to-date review of the rationale sustaining the use of CPET for functional evaluation of cardiac patients in both the clinical and research settings, describing parameters obtainable either from ramp incremental or step constant-power CPET and illustrating the wealth of information obtainable through an experienced use of this powerful tool. The choice of parameters to be measured will depend on the specific goals of functional evaluation in the individual patient, namely, exercise tolerance assessment, training prescription, treatment efficacy evaluation, and/or investigation of exercise-induced adaptations of the oxygen transport/utilization system. The full potentialities of CPET in the clinical and research setting still remain largely underused and strong efforts are recommended to promote a more widespread use of CPET in the functional evaluation of cardiac patients.
Collapse
|
187
|
Fontana P, Boutellier U, Knöpfli-Lenzin C. Time to exhaustion at maximal lactate steady state is similar for cycling and running in moderately trained subjects. Eur J Appl Physiol 2009; 107:187-92. [PMID: 19551404 DOI: 10.1007/s00421-009-1111-9] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/05/2009] [Indexed: 10/20/2022]
Abstract
We compared time to exhaustion (t(lim)) at maximal lactate steady state (MLSS) between cycling and running, investigated if oxygen consumption, ventilation, blood lactate concentration, and perceived exertion differ between the exercise modes, and established whether MLSS can be determined for cycling and running using the same criteria. MLSS was determined in 15 moderately trained men (30 +/- 6 years, 77 +/- 6 kg) by several constant-load tests to exhaustion in cycling and running. Heart rate, oxygen consumption, and ventilation were recorded continuously. Blood lactate concentration and perceived exertion were measured every 5 min. t (lim) (37.7 +/- 8.9 vs. 34.4 +/- 5.4 min) and perceived exertion (7.2 +/- 1.7 vs. 7.2 +/- 1.5) were similar for cycling and running. Heart rate (165 +/- 8 vs. 175 +/- 10 min(-1); P < 0.01), oxygen consumption (3.1 +/- 0.3 vs. 3.4 +/- 0.3 l min(-1); P < 0.001) and ventilation (93 +/- 12 vs. 103 +/- 16 l min(-1); P < 0.01) were lower for cycling compared to running, respectively, whereas blood lactate concentration (5.6 +/- 1.7 vs. 4.3 +/- 1.3 mmol l(-1); P < 0.05) was higher for cycling. t(lim) at MLSS is similar for cycling and running, despite absolute differences in heart rate, ventilation, blood lactate concentration, and oxygen consumption. This may be explained by the relatively equal cardiorespiratory demand at MLSS. Additionally, the similar t(lim) for cycling and running allows the same criteria to be used for determining MLSS in both exercise modes.
Collapse
Affiliation(s)
- Piero Fontana
- Exercise Physiology, Institute of Human Movement Sciences, ETH Zurich, Zurich, Switzerland.
| | | | | |
Collapse
|
188
|
Kacerovsky-Bielesz G, Chmelik M, Ling C, Pokan R, Szendroedi J, Farukuoye M, Kacerovsky M, Schmid AI, Gruber S, Wolzt M, Moser E, Pacini G, Smekal G, Groop L, Roden M. Short-term exercise training does not stimulate skeletal muscle ATP synthesis in relatives of humans with type 2 diabetes. Diabetes 2009; 58:1333-41. [PMID: 19265027 PMCID: PMC2682667 DOI: 10.2337/db08-1240] [Citation(s) in RCA: 56] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
OBJECTIVE We tested the hypothesis that short-term exercise training improves hereditary insulin resistance by stimulating ATP synthesis and investigated associations with gene polymorphisms. RESEARCH DESIGN AND METHODS We studied 24 nonobese first-degree relatives of type 2 diabetic patients and 12 control subjects at rest and 48 h after three bouts of exercise. In addition to measurements of oxygen uptake and insulin sensitivity (oral glucose tolerance test), ectopic lipids and mitochondrial ATP synthesis were assessed using(1)H and(31)P magnetic resonance spectroscopy, respectively. They were genotyped for polymorphisms in genes regulating mitochondrial function, PPARGC1A (rs8192678) and NDUFB6 (rs540467). RESULTS Relatives had slightly lower (P = 0.012) insulin sensitivity than control subjects. In control subjects, ATP synthase flux rose by 18% (P = 0.0001), being 23% higher (P = 0.002) than that in relatives after exercise training. Relatives responding to exercise training with increased ATP synthesis (+19%, P = 0.009) showed improved insulin sensitivity (P = 0.009) compared with those whose insulin sensitivity did not improve. A polymorphism in the NDUFB6 gene from respiratory chain complex I related to ATP synthesis (P = 0.02) and insulin sensitivity response to exercise training (P = 0.05). ATP synthase flux correlated with O(2)uptake and insulin sensitivity. CONCLUSIONS The ability of short-term exercise to stimulate ATP production distinguished individuals with improved insulin sensitivity from those whose insulin sensitivity did not improve. In addition, the NDUFB6 gene polymorphism appeared to modulate this adaptation. This finding suggests that genes involved in mitochondrial function contribute to the response of ATP synthesis to exercise training.
Collapse
Affiliation(s)
- Gertrud Kacerovsky-Bielesz
- Medical Department, Hanusch Hospital, Vienna, Austria
- Karl-Landsteiner Institute for Endocrinology and Metabolism, Vienna, Austria
| | - Marek Chmelik
- Karl-Landsteiner Institute for Endocrinology and Metabolism, Vienna, Austria
- MR Center of Excellence, Medical University of Vienna, Vienna, Austria
| | - Charlotte Ling
- Department of Clinical Sciences, Lund University, Malmö, Sweden
| | - Rochus Pokan
- Department of Sports and Exercise Physiology, University of Vienna, Vienna, Austria
| | - Julia Szendroedi
- Medical Department, Hanusch Hospital, Vienna, Austria
- Karl-Landsteiner Institute for Endocrinology and Metabolism, Vienna, Austria
| | - Michaela Farukuoye
- Karl-Landsteiner Institute for Endocrinology and Metabolism, Vienna, Austria
| | - Michaela Kacerovsky
- Karl-Landsteiner Institute for Endocrinology and Metabolism, Vienna, Austria
| | - Albrecht I. Schmid
- Karl-Landsteiner Institute for Endocrinology and Metabolism, Vienna, Austria
- MR Center of Excellence, Medical University of Vienna, Vienna, Austria
| | - Stephan Gruber
- MR Center of Excellence, Medical University of Vienna, Vienna, Austria
| | - Michael Wolzt
- Department of Clinical Pharmacology, Medical University of Vienna, Vienna, Austria
| | - Ewald Moser
- MR Center of Excellence, Medical University of Vienna, Vienna, Austria
| | - Giovanni Pacini
- Metabolic Unit, Institute of Biomedical Engineering, Consiglio Nazionale delle Ricerche, Padua, Italy
| | - Gerhard Smekal
- Department of Sports and Exercise Physiology, University of Vienna, Vienna, Austria
| | - Leif Groop
- Department of Clinical Sciences, Lund University, Malmö, Sweden
| | - Michael Roden
- Medical Department, Hanusch Hospital, Vienna, Austria
- Karl-Landsteiner Institute for Endocrinology and Metabolism, Vienna, Austria
- Institute for Clinical Diabetology, German Diabetes Center-Leibniz Center for Diabetes Research, Department of Medicine/Metabolic Diseases, Heinrich Heine University Düsseldorf, Düsseldorf, Germany
- Corresponding author: Michael Roden,
| |
Collapse
|
189
|
|
190
|
The Effects of Wearing Lower-Body Compression Garments During Endurance Cycling. Int J Sports Physiol Perform 2008; 3:424-38. [DOI: 10.1123/ijspp.3.4.424] [Citation(s) in RCA: 69] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Purpose:The present investigation examined the physiological and performance effects of lower-body compression garments (LBCG) during a one-hour cycling time-trial in well-trained cyclists.Methods:Twelve well-trained male cyclists ([mean ± SD] age: 20.5 ± 3.6 years; height: 177.5 ± 4.9 cm; body mass: 70.5 ± 7.5 kg; VO2max: 55.2 ± 6.8 mL·kg−1·min−1) volunteered for the study. Each subject completed two randomly ordered stepwise incremental tests and two randomly ordered one-hour time trials (1HTT) wearing either full-length SportSkins Classic LBCG or underwear briefs (control). Blood lactate concentration ([BLa−]), heart rate (HR), oxygen consumption (VO2) and muscle oxygenation (mOxy) were recorded throughout each test. Indicators of cycling endurance performance were anaerobic threshold (AnT) and VO2max values from the incremental test, and mean power (W), peak power (W), and total work (kJ) from the 1HTT Magnitude-based inferences were used to determine if LBCG demonstrated any performance and/or physiological benefits.Results:A likely practically significant increase (86%:12%:2%; η2 = 0.6) in power output at AnT was observed in the LBCG condition (CONT: 245.9 ± 55.7 W; LBCG: 259.8 ± 44.6 W). Further, a possible practically significant improvement (78%:19%:3%; η2 = 0.6) was reported in muscle oxygenation economy (W·%mOxy−1) across the 1HTT (mOxy: CONT: 52.2 ± 12.2%; LBCG: 57.3 ± 8.2%).Conclusions:The present results demonstrated limited physiological benefits and no performance enhancement through wearing LBCG during a cycling time trial.
Collapse
|
191
|
Thomas V, Costes F, Chatagnon M, Pouilly JP, Busso T. A comparison of lactate indices during ramp exercise using modelling techniques and conventional methods. J Sports Sci 2008; 26:1387-95. [DOI: 10.1080/02640410802104920] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
|
192
|
Ribeiro LFP, Gonçalves CGS, Kater DP, Lima MCS, Gobatto CA. Influence of recovery manipulation after hyperlactemia induction on the lactate minimum intensity. Eur J Appl Physiol 2008; 105:159-65. [PMID: 18853175 DOI: 10.1007/s00421-008-0885-5] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/23/2008] [Indexed: 10/21/2022]
Abstract
This study analyzed the influence of recovery phase manipulation after hyperlactemia induction on the lactate minimum intensity during treadmill running. Twelve male runners (24.6 +/- 6.3 years; 172 +/- 8.0 cm and 62.6 +/- 6.1 kg) performed three lactate minimum tests involving passive (LMT(P)) and active recoveries at 30%vVO(2max) (LMT(A30)) and 50%vVO(2max) (LMT(A50)) in the 8-min period following initial sprints. During subsequent graded exercise, lactate minimum speed and VO(2) in LMT(A50) (12.8 +/- 1.5 km h(-1) and 40.3 +/- 5.1 ml kg(-1) min(-1)) were significantly lower (P < 0.05) than those in LMT(A30) (13.3 +/- 1.6 km h(-1) and 42.9 +/- 5.3 ml kg(-1) min(-1)) and LMT(P) (13.8 +/- 1.6 km h(-1) and 43.6 +/- 6.1 ml kg(-1) min(-1)). In addition, lactate minimum speed in LMT(A30) was significantly lower (P < 0.05) than that in LMT(P). These results suggest that lactate minimum intensity is lowered by active recovery after hyperlactemia induction in an intensity-dependent manner compared to passive recovery.
Collapse
|
193
|
Silva ASR, Santhiago V, Papoti M, Gobatto CA. Hematological parameters and anaerobic threshold in Brazilian soccer players throughout a training program. Int J Lab Hematol 2008; 30:158-66. [PMID: 18333848 DOI: 10.1111/j.1751-553x.2007.00919.x] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
We assessed the responses of hematological parameters and their relationship to the anaerobic threshold of Brazilian soccer players during a training program. Twelve athletes were evaluated at the beginning (week 0, T1), in the middle (week 6, T2), and at the end (week 12, T3) of the soccer training program. On the first day at 7:30 am, before collecting the blood sample at rest for the determination of the hematological parameters, the athletes were conducted to the anthropometric evaluation. On the second day at 8:30 am, the athletes had their anaerobic threshold measured. Analysis of variance with Newman-Keuls'post hoc was used for statistical comparisons between the parameters measured during the soccer training program. Correlations between the parameters analyzed were determined using the Pearson's correlation coefficient. Erythrocytes concentration, hemoglobin, and hematocrit were significantly increased from T1 to T2. The specific soccer training program led to a rise in erythrocytes, hemoglobin, and hematocrit from T1 to T2. We assumed that these results occurred due to the plasma volume reduction and may be explained by the soccer training program characteristics. Furthermore, we did not observe any correlation between the anaerobic threshold and the hematological parameters.
Collapse
Affiliation(s)
- A S R Silva
- Department of Physical Education, Bioscience Institute, University of Sao Paulo State Unesp, Rio Claro, Sao Paulo, Brazil.
| | | | | | | |
Collapse
|
194
|
Figueira TR, Caputo F, Pelarigo JG, Denadai BS. Influence of exercise mode and maximal lactate-steady-state concentration on the validity of OBLA to predict maximal lactate-steady-state in active individuals. J Sci Med Sport 2008; 11:280-6. [PMID: 17553745 DOI: 10.1016/j.jsams.2007.02.016] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2006] [Revised: 11/07/2006] [Accepted: 02/03/2007] [Indexed: 11/21/2022]
Abstract
The aim of this study was to analyze the effects of exercise mode on the validity of onset of blood lactate accumulation (OBLA-3.5-mM fixed blood lactate concentration) to predict the work-rate at maximal lactate steady state (MLSS(work-rate)). Eleven recreationally active males (21.3+/-2.9 years, 72.8+/-6.7kg, 1.78+/-0.1m) performed randomly incremental tests to determine OBLA (stage duration of 3min), and 2 to 4 constants work-rate exercise tests to directly determine maximal lactate steady state parameters on a cycle-ergometer and treadmill. For both exercise modes, the OBLA was significantly correlated to MLSS(work-rate), (cycling: r=0.81 p=0.002; running: r=0.94, p<0.001). OBLA (156.2+/-41.3W) was lower than MLSS(work-rate) (179.6+/-26.4W) during cycling exercise (p=0.007). However, for running exercise, there was no difference between OBLA (3.2+/-0.6ms(-1)) and MLSS(work-rate) (3.1+/-0.4ms(-1)). The difference between OBLA and MLSS(work-rate) on the cycle-ergometer (r=0.86; p<0.001) and treadmill (r=0.64; p=0.048) was significantly related to the specific MLSS. We can conclude that the validity of OBLA on predicting MLSS(work-rate) is dependent on exercise mode and that its disagreement is related to individual variations in MLSS.
Collapse
|
195
|
Ramos-Jiménez A, Hernández-Torres RP, Torres-Durán PV, Romero-Gonzalez J, Mascher D, Posadas-Romero C, Juárez-Oropeza MA. The Respiratory Exchange Ratio is Associated with Fitness Indicators Both in Trained and Untrained Men: A Possible Application for People with Reduced Exercise Tolerance. CLINICAL MEDICINE. CIRCULATORY, RESPIRATORY AND PULMONARY MEDICINE 2008; 2:1-9. [PMID: 21157516 PMCID: PMC2990231 DOI: 10.4137/ccrpm.s449] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Background: The respiratory exchange ratio (RER) indirectly shows the muscle’s oxidative capacity to get energy. Sedentarism, exercise and physically active lifestyles modify it. For that reason, this study evaluates the associations between RER during sub-maximum exercise and other well established fitness indicators (body fat, maximum heart rate, maximum O2 uptake, workload, and lactate threshold), in physically active trained and untrained men. Methods: The RER, O2 uptake and blood lactate were measured in eight endurance trained and eight untrained men (age, 22.9 ± 4.5 vs. 21.9 ± 2.8 years; body mass, 67.1 ± 5.4 vs. 72.2 ± 7.7 kg; body fat, 10.6 ± 2.4% vs. 16.6 ± 3.8% and maximum O2 uptake, 68.9 ± 6.3 vs. 51.6 ± 5.8 ml•kg−1•min−1), during maximum exercise test and during three different sub-maximum exercises at fixed workload: below, within or above the lactate threshold. Results: Endurance trained men presented higher O2 uptake, lower blood lactate concentrations and lower RER values than those in untrained men at the three similar relative workloads. Even though with these differences in RER, a strong association (p < 0.05) of RER during sub-maximum exercise with the other well established fitness indicators was observed, and both maximum O2 uptake and lactate threshold determined more than 57% of its variance (p < 0.05). Conclusions: These data demonstrate that RER measurement under sub-maximum exercise conditions was well correlated with other established physical fitness indicators, despite training condition. Furthermore, the results suggest that RER could help obtain an easy approach of fitness status under low exercise intensity and could be utilized in subjects with reduced exercise tolerance.
Collapse
Affiliation(s)
- Arnulfo Ramos-Jiménez
- Department of Basic Science, Biomedical Science Institute, UACJ, Cd. Juarez Chih, Mexico
| | | | | | | | | | | | | |
Collapse
|
196
|
Nixon S, Sieg A, Delgado-Charro MB, Guy RH. Reverse iontophoresis of L‐lactate: In vitro and in vivo studies. J Pharm Sci 2007; 96:3457-65. [PMID: 17506512 DOI: 10.1002/jps.20989] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
This work investigates the reverse iontophoretic extraction of lactate, a widely used marker of tissue distress in critically ill patients and of sports performance. In vitro experiments were performed to establish the relationship between subdermal lactate levels and lactate iontophoretic extraction fluxes. Subsequently, the iontophoretic extraction of lactate was performed in vivo in healthy volunteers. Lactate was quickly and easily extracted by iontophoresis both in vitro and in vivo. During a short initial phase, iontophoresis extracts the lactate present in the skin reservoir, providing information of relevance, perhaps, for dermatological and cosmetic applications. In a second step, lactate is extracted from the interstitial subdermal fluid allowing local lactate kinetics to be followed in a completely non-invasive way. The simultaneous in vivo extraction of chloride, and its possible role as an internal standard to calibrate lactate reverse iontophoretic fluxes, was also demonstrated. Despite these positive findings, however, considerably more research is necessary to eliminate potential artefacts and to facilitate interpretation of the data.
Collapse
Affiliation(s)
- Susan Nixon
- Novartis Consumer Health SA, Nyon, Switzerland
| | | | | | | |
Collapse
|
197
|
Lactate metabolism in anoxic turtles: an integrative review. J Comp Physiol B 2007; 178:133-48. [PMID: 17940776 DOI: 10.1007/s00360-007-0212-1] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2007] [Revised: 09/11/2007] [Accepted: 09/17/2007] [Indexed: 10/22/2022]
Abstract
Painted turtles can accumulate lactic acid to extremely high concentrations during long-term anoxic submergence, with plasma lactate exceeding 200 mmol l(-1). The aims of this review are twofold: (1) To summarize aspects of lactate metabolism in anoxic turtles that have not been reviewed previously and (2) To identify gaps in our knowledge of turtle lactate metabolism by comparing it with lactate metabolism during and after exercise in other vertebrates. The topics reviewed include analyses of lactate's fate during recovery, the effects of temperature on lactate accumulation and clearance, the interaction of activity and recovery metabolism, fuel utilization during recovery, stress hormone responses during and following anoxia, and cellular lactate transport mechanisms. An analysis of lactate metabolism in anoxic turtles in the context of the 'lactate shuttle' hypothesis is also presented.
Collapse
|
198
|
de Araujo GG, Papoti M, Manchado FDB, de Mello MAR, Gobatto CA. Protocols for hyperlactatemia induction in the lactate minimum test adapted to swimming rats. Comp Biochem Physiol A Mol Integr Physiol 2007; 148:888-92. [PMID: 17964836 DOI: 10.1016/j.cbpa.2007.09.002] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2007] [Revised: 09/06/2007] [Accepted: 09/06/2007] [Indexed: 11/25/2022]
Abstract
The lactate minimum test (LACmin) has been considered an important indicator of endurance exercise capacity and a single session protocol can predict the maximal steady state lactate (MLSS). The objective of this study was to determine the best swimming protocol to induce hyperlactatemia in order to assure the LACmin in rats (Rattus norvegicus), standardized to four different protocols (P) of lactate elevation. The protocols were P1: 6 min of intermittent jumping exercise in water (load of 50% of the body weight - bw); P2: two 13% bw load swimming bouts until exhaustion (tlim); P3: one tlim 13% bw load swimming bout; and P4: two 13% bw load swimming bouts (1st 30 s, 2nd to tlim), separated by a 30 s interval. The incremental phase of LACmin beginning with initial loads of 4% bw, increased in 0.5% at each 5 min. Peak lactate concentration was collected after 5, 7 and 9 min (mmol L(-1)) and differed among the protocols P1 (15.2+/-0.4, 14.9+/-0.7, 14.8+/-0.6) and P2 (14.0+/-0.4, 14.9+/-0.4, 15.5+/-0.5) compared to P3 (5.1+/-0.1, 5.6+/-0.3, 5.6+/-0.3) and P4 (4.7+/-0.2, 6.8+/-0.2, 7.1+/-0.2). The LACmin determination success rates were 58%, 55%, 80% and 91% in P1, P2, P3 and P4 protocols, respectively. The MLSS did not differ from LACmin in any protocol. The LACmin obtained from P4 protocol showed better assurance for the MLSS identification in most of the tested rats.
Collapse
Affiliation(s)
- Gustavo Gomes de Araujo
- Laboratory of Sport Applied Physiology, Sao Paulo State University, UNESP-IB, Rio Claro SP, Brazil
| | | | | | | | | |
Collapse
|
199
|
Angeli G, Barros TLD, Barros DFLD, Lima M. Investigação dos efeitos da suplementação oral de arginina no aumento de força e massa muscular. REV BRAS MED ESPORTE 2007. [DOI: 10.1590/s1517-86922007000200012] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
INTRODUÇÃO: A administração oral de arginina tem sido relacionada com a melhora do desempenho físico por provável diminuição da fadiga muscular, decorrente do efeito vasodilatador do óxido nítrico sobre os músculos esqueléticos. OBJETIVO: Avaliar os efeitos da administração oral de L-arginina durante um programa de exercícios com pesos. MÉTODOS: 20 indivíduos do sexo masculino foram submetidos a oito semanas de treinamento com pesos (três vezes por semana), divididos aleatoriamente em dois grupos: ARG e CON. O grupo ARG fez uso de três gramas de L-arginina + vitamina C, durante as oito semanas e o grupo CON utilizou apenas vitamina C (grupo controle). RESULTADOS: Após oito semanas de treinamento, o grupo ARG apresentou valores de peso corporal e massa magra significativamente maiores (p < 0,05), percentual de gordura corporal significativamente menor (p < 0,05) e força de membros inferiores significantemente maior (p < 0,05), enquanto o grupo CON não mostrou diferenças significativas, para o mesmo período. CONCLUSÃO: A administração oral de arginina associada a um programa de treinamento com pesos potencializou os estímulos do exercício ao nível da musculatura esquelética, proporcionando o aumento de força e de massa muscular.
Collapse
|
200
|
Contarteze RVL, Manchado FDB, Gobatto CA, De Mello MAR. Stress biomarkers in rats submitted to swimming and treadmill running exercises. Comp Biochem Physiol A Mol Integr Physiol 2007; 151:415-422. [PMID: 17428717 DOI: 10.1016/j.cbpa.2007.03.005] [Citation(s) in RCA: 107] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2006] [Revised: 02/26/2007] [Accepted: 03/06/2007] [Indexed: 10/23/2022]
Abstract
The objective of the present work was to compare stress biomarkers (serum ACTH and corticosterone hormones) during known intensity swimming and treadmill running exercises performed by rats. Adult Wistar rats (n=41) weighing 320-400 g at the beginning and 420-500 g at the end of the experiment, previously adapted to exercise and with Maximal Lactate Steady State (MLSS) already determined were used. The animals were divided into the following subgroups: (1) sacrificed shortly after session of 25 min of exercise (swimming or treadmill) at the MLSS intensity or (2) sacrificed after exhaustive exercise (swimming or treadmill) at intensity 25% higher than MLSS. For comparison, a control group C was sacrificed at rest. Two-way ANOVA was used to identify differences in the stress parameters (P<0.05). At both exercise intensities serum ACTH concentrations were significantly higher for the swimming group compared to running and control groups, while serum corticosterone concentrations in swimming and running groups were significantly higher than in the control group. The differences were more pronounced at the higher intensity (25% higher than MLSS). The swimming group showed higher concentrations for both hormones in relation to the running group. Only acute swimming exercise induced activity of the hypothalamic-pituitary-adrenal axis responses expected to stress: elevations in the serum ACTH and corticosterone concentrations.
Collapse
Affiliation(s)
| | - Fúlvia De Barros Manchado
- Department of Physical Education, UNESP, University of Sao Paulo State, Rio Claro, São Paulo, Brazil
| | - Claudio Alexandre Gobatto
- Department of Physical Education, UNESP, University of Sao Paulo State, Rio Claro, São Paulo, Brazil
| | | |
Collapse
|