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1.
Artigo em Inglês | MEDLINE | ID: mdl-32748826

RESUMO

Endurance physical exercise is accompanied by subjective perceptions of exertion (reported perceived exertion, RPE), emotional valence, and arousal. These constructs have been hypothesized to serve as the basis for the exerciser to make decisions regarding when to stop, how to regulate pace, and whether or not to exercise again. In dual physical-cognitive tasks, the mental (executive) workload generated by the cognitive task has been shown to influence these perceptions, in ways that could also influence exercise-related decisions. In the present work, we intend to replicate and extend previous findings that manipulating the amount of executive load imposed by a mental task, performed concomitantly with a submaximal cycling session, influenced emotional states but not perceived exertion. Participants (experienced triathletes) were asked to perform a submaximal cycling task in two conditions with different executive demands (a two-back version of the n-back task vs. oddball) but equated in external physical load. Results showed that the higher executive load condition elicited more arousal and less positive valence than the lower load condition. However, both conditions did not differ in RPE. This experimental dissociation suggests that perceived exertion and its emotional correlates are not interchangeable, which opens the possibility that they could play different roles in exercise-related decision-making.


Assuntos
Nível de Alerta/fisiologia , Ciclismo/fisiologia , Função Executiva/fisiologia , Exercício Físico , Esforço Físico/fisiologia , Afeto , Emoções , Humanos , Carga de Trabalho
2.
Am J Physiol Regul Integr Comp Physiol ; 319(3): R315-R322, 2020 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-32697652

RESUMO

During exhaustive ramp-incremental cycling tests, the incidence of O2 uptake (V̇o2) plateaus is low. To verify the attainment of maximum V̇o2 (V̇o2max), it is recommended that a trial at a power output (PO) corresponding to 110% of the ramp-derived peak (POpeak) is performed. It remains unclear whether verification trials set at this PO can be tolerated for long enough to allow attainment of V̇o2max. Eleven recreationally trained individuals performed five ramp tests of varying slope (5, 10, 15, 25, and 30 W/min), each followed, in series, by two verification trials: the first at 110% POpeak of the 25 W/min ramp and the second at 110% POpeak attained in the preceding ramp test. Exercise duration of the first verification trial was on average 81 ± 15 s (CV = 9 ± 3%) versus 162 ± 32, 121 ± 24, 103 ± 15, and 73 ± 10 s for the second verification trials at 110% of POpeak of the 5, 10, 15, and 30 W/min ramp tests, respectively (P < 0.05). Compared with the highest V̇o2 recorded during ramp tests, V̇o2 from the subsequent verification trials was not different for the 5, 10, and 15 W/min ramp tests (P > 0.05) but was lower for the 25 and 30 W/min ramp tests (P < 0.05). Verification trials at 110% POpeak of rapidly incrementing ramp tests (i.e., 25 W/min) were not sustained for long enough to allow the attainment of V̇o2max. With commonly used rapidly incrementing ramp tests engendering exhaustion within 8-12 min, verification trials less than POpeak should be preferred as they can be sustained sufficiently long to allow the attainment of V̇o2max.


Assuntos
Transporte Biológico/fisiologia , Exercício Físico/fisiologia , Consumo de Oxigênio/fisiologia , Esforço Físico/fisiologia , Adulto , Teste de Esforço/métodos , Frequência Cardíaca/fisiologia , Humanos , Masculino
3.
Am J Physiol Endocrinol Metab ; 319(2): E354-E362, 2020 08 01.
Artigo em Inglês | MEDLINE | ID: mdl-32603260

RESUMO

Browning of white adipose tissue (WAT) has been shown to reduce obesity and obesity-related complications, suggesting that factors that promote WAT browning may have applications in the development of therapeutic strategies for treating obesity. Here, we show that ablation of spinophilin (SPL), a ubiquitously expressed, multidomain scaffolding protein, increases metabolism and improves energy balance. Male and female SPL knockout (KO) and wild-type (WT) littermate controls were fed a chow diet or a high-fat diet (HFD). Body weight, hepatic steatosis, glucose and insulin tolerance, physical activity, and expression of browning genes in adipose tissues were measured and compared. Male SPL knockout (KO) mice fed a chow diet were significantly leaner, had lower body weights, and exhibited better glucose tolerance and insulin sensitivity than wild-type (WT) littermate controls. When fed an HFD, SPL KO mice were protected from increased body fat, weight gain, hepatic steatosis, hyperinsulinemia, and insulin resistance. Physical activity of SPL KO mice was markedly increased compared with WT controls. Furthermore, expression of the brown adipocyte marker, uncoupling protein-1 (UCP-1), and the mitochondrial activity markers, cd137 and c-idea, were significantly increased in visceral WAT (vWAT) of SPL KO mice, suggesting that SPL knockout protected the mice from HFD-induced obesity and its metabolic complications, at least in part, by promoting the browning of white adipocytes in vWAT. Our data identify a critical role of SPL in regulating glucose homeostasis, obesity, and adipocyte browning. These results suggest SPL may serve as a drug target for obesity and diabetes.


Assuntos
Dieta Hiperlipídica/efeitos adversos , Resistência à Insulina/fisiologia , Proteínas dos Microfilamentos/deficiência , Proteínas do Tecido Nervoso/deficiência , Obesidade/prevenção & controle , Adiponectina/sangue , Tecido Adiposo Marrom/fisiopatologia , Tecido Adiposo Branco/fisiopatologia , Animais , Metabolismo Energético , Fígado Gorduroso/fisiopatologia , Fígado Gorduroso/prevenção & controle , Feminino , Leptina/sangue , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Proteínas dos Microfilamentos/fisiologia , Proteínas do Tecido Nervoso/fisiologia , Obesidade/etiologia , Obesidade/fisiopatologia , Esforço Físico/fisiologia
4.
Int J Sports Physiol Perform ; 15(5): 696-704, 2020 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-32698124

RESUMO

PURPOSE: To investigate within-player effect, between-player effect, and individual response of external training load from player tracking devices on session rating of perceived exertion training load (sRPE-TL) in elite football players. METHODS: The authors collected sRPE-TL from 18 outfield players in 21 training sessions. Total distance, high-speed running distance (>14.4 m/s), very high-speed running distance (>19.8 m/s), PlayerLoad™, PlayerLoad2D™, and high-intensity events (HIE > 1.5, HIE > 2.5, and HIE > 3.5 m/s) were extracted from the tracking devices. The authors modeled within-player and between-player effects of single external load variables on sRPE-TL, and multiple levels of variability, using a linear mixed model. The effect of 2 SDs of external load on sRPE-TL was evaluated with magnitude-based inferences. RESULTS: Total distance, PlayerLoad™, PlayerLoad2D™, and HIE > 1.5 had most likely substantial within-player effects on sRPE-TL (100%-106%, very large effect sizes). Moreover, the authors observed likely substantial between-player effects (12%-19%, small to moderate effect sizes) from the majority of the external load variables and likely to very likely substantial individual responses of PlayerLoad™, high-speed running distance, very high-speed running distance, and HIE > 1.5 (19%-30% coefficient of variation, moderate to large effect sizes). Finally, sRPE-TL showed large to very large between-session variability with all external load variables. CONCLUSIONS: External load variables with low intensity-thresholds had the strongest relationship with sRPE-TL. Furthermore, the between-player effect of external load and the individual response to external load advocate for monitoring sRPE-TL in addition to external load. Finally, the large between-session variability in sRPE-TL demonstrates that substantial amounts of sRPE-TL in training sessions are not explained by single external load variables.


Assuntos
Percepção/fisiologia , Condicionamento Físico Humano/métodos , Esforço Físico/fisiologia , Futebol/fisiologia , Adulto , Comportamento Competitivo/fisiologia , Monitores de Aptidão Física , Humanos , Masculino , Corrida/fisiologia
5.
Nat Commun ; 11(1): 3555, 2020 07 16.
Artigo em Inglês | MEDLINE | ID: mdl-32678082

RESUMO

Interoceptive feedback transmitted via the vagus nerve plays a vital role in motivation by tuning actions according to physiological needs. Whereas vagus nerve stimulation (VNS) reinforces actions in animals, motivational effects elicited by VNS in humans are still largely elusive. Here, we applied non-invasive transcutaneous auricular VNS (taVNS) on the left or right ear while participants exerted effort to earn rewards using a randomized cross-over design (vs. sham). In line with preclinical studies, acute taVNS enhances invigoration of effort, and stimulation on the left side primarily facilitates invigoration for food rewards. In contrast, we do not find conclusive evidence that acute taVNS affects effort maintenance or wanting ratings. Collectively, our results suggest that taVNS enhances reward-seeking by boosting invigoration, not effort maintenance and that the stimulation side affects generalization beyond food reward. Thus, taVNS may enhance the pursuit of prospective rewards which may pave avenues to treat motivational deficiencies.


Assuntos
Motivação/fisiologia , Recompensa , Estimulação do Nervo Vago , Nervo Vago/fisiologia , Adulto , Análise Custo-Benefício , Estudos Cross-Over , Orelha/inervação , Feminino , Humanos , Masculino , Esforço Físico/fisiologia , Distribuição Aleatória
6.
Artigo em Inglês | MEDLINE | ID: mdl-32635507

RESUMO

Indoor cycling's popularity is related to the combination of music and exercise leading to higher levels of exercise intensity. It was our objective to determine the efficacy of heart rate and rating of perceived exertion in controlling the intensity of indoor cycling classes and to quantify their association with oxygen uptake. Twelve experienced males performed three indoor cycling sessions of 45 min that differed in the way the intensity was controlled: (i) oxygen uptake; (ii) heart rate; and (iii) rating of perceived exertion using the OMNI-Cycling. The oxygen uptake levels were significantly higher (p = 0.007; µp2 = 0.254) in oxygen uptake than heart rate sessions. Oxygen uptake related to body mass was significantly higher (p < 0.005) in the oxygen uptake sessions compared with other sessions. Strong correlations were observed between oxygen uptake mean in the oxygen uptake and rating of perceived exertion sessions (r =0.986, p < 0.0001) and between oxygen uptake mean in the oxygen uptake and heart rate sessions (r = 0.977, p < 0.0001). Both heart rate and rating of perceived exertion are effective in controlling the intensity of indoor cycling classes in experienced subjects. However, the use of rating of perceived exertion is easier to use and does not require special instrumentation.


Assuntos
Ciclismo/fisiologia , Frequência Cardíaca/fisiologia , Consumo de Oxigênio/fisiologia , Esforço Físico/fisiologia , Adulto , Exercício Físico , Teste de Esforço , Feminino , Humanos , Masculino
7.
Int J Sports Med ; 41(11): 736-743, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32485779

RESUMO

Injuries of runners reduce the ability to train and hinder competing. Literature shows that the relation between potential risk factors and injuries are not definitive, limited, and inconsistent. In team sports, workload derivatives were identified as risk factors. However, there is an absence of literature in running on workload derivatives. This study used the workload derivatives acute workload, chronic workload, and acute: chronic workload ratios to investigate the relation between workload and injury risk in running. Twenty-three competitive runners kept a daily training log for 24 months. The runners reported training duration, training intensity and injuries. One-week (acute) and 4-week (chronic) workloads were calculated as the average of training duration multiplied by training intensity. The acute:chronic workload ratio was determined dividing the acute and chronic workloads. Results show that a fortnightly low increase of the acute:chronic workload ratio (0.10-0.78) led to an increased risk of sustaining an injury (p<0.001). Besides, a low increase of the acute:chronic workload ratio (0.05-0.62) between the second week and third week before an injury showed an association with increased injury risk (p=0.013). These findings demonstrate that the acute:chronic workload ratio relates to injury risk.


Assuntos
Comportamento Competitivo/fisiologia , Condicionamento Físico Humano/fisiologia , Corrida/lesões , Traumatismos em Atletas/fisiopatologia , Feminino , Humanos , Masculino , Percepção/fisiologia , Condicionamento Físico Humano/métodos , Esforço Físico/fisiologia , Fatores de Risco , Fatores de Tempo , Adulto Jovem
8.
Int J Sports Med ; 41(11): 759-765, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32492734

RESUMO

A combination of yoga and blood flow restriction, each of which elicits marked pressor responses, may further increase blood pressure and myocardial oxygen demand. To determine the impact of a combination of yoga and blood flow restriction on hemodynamic responses, twenty young healthy participants performed 20 yoga poses with/without blood flow restriction bands placed on both legs. At baseline, there were no significant differences in any of the variables between the blood flow restriction and non-blood flow restriction conditions. Blood pressure and heart rate increased in response to the various yoga poses (p<0.01) but were not different between the blood flow restriction and non-blood flow restriction conditions. Rate-pressure products, an index of myocardial oxygen demand, increased significantly during yoga exercises with no significant differences between the two conditions. Rating of perceived exertion was not different between the conditions. Blood lactate concentration was significantly greater after performing yoga with blood flow restriction bands (p=0.007). Cardio-ankle vascular index, an index of arterial stiffness, decreased similarly after yoga exercise in both conditions while flow-mediated dilation remained unchanged. In conclusion, the use of lower body blood flow restriction bands in combination with yoga did not result in additive or synergistic hemodynamic and pressor responses.


Assuntos
Pressão Sanguínea , Hemodinâmica , Condicionamento Físico Humano/métodos , Fluxo Sanguíneo Regional , Coxa da Perna/irrigação sanguínea , Ioga , Adolescente , Adulto , Estudos Cross-Over , Endotélio Vascular/fisiologia , Feminino , Frequência Cardíaca , Humanos , Ácido Láctico/sangue , Masculino , Miocárdio/metabolismo , Consumo de Oxigênio , Percepção/fisiologia , Condicionamento Físico Humano/fisiologia , Esforço Físico/fisiologia , Rigidez Vascular , Vasodilatação , Adulto Jovem
9.
J Sports Med Phys Fitness ; 60(7): 992-998, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32597616

RESUMO

BACKGROUND: The rest interval between sets can affect the responses to resistance training. Thus, the purpose of this study was to compare the effects of different rest intervals (RI) on volume, density, and rating of perceived exertion (RPE) when adopting a crescent pyramid (CP) system. METHODS: Twenty young women (21.1±2.6 years, 1.59±0.06 m, 58.5±9.3 kg) participated in this study. All participants performed three experimental sessions of the leg press exercise in 5 sets until voluntary muscular failure at 60%, 65%, 70%, 75%, and 80% of one-repetition maximum (1RM). A randomized and crossover design was used so that in each session one of three RI (RI-1 = 1 min, RI-2 = 2 min, and RI-3 = 3 min) was tested. RESULTS: The participants performed a significantly larger volume in the RI-3 (12820±3134 kg) when compared to RI-1 (10367±3053 kg) condition (P<0.05). The volume did not differ between RI-2 and RI-3 (P>0.05). The density was higher (P<0.05) in RI-1 (43.1±12.7 kg/s) when compared RI-2 (25.6±5.8 kg/s) and RI-3 (17.7±4.3 kg/s). The RI-2 presented higher density compared to RI-3 condition (P<0.05). The RPE was not different between the three conditions (P>0.05). CONCLUSIONS: The use of 2 minutes of rest between sets allowed the performance of a high volume-load and density of the session in young women. In addition, the three experimental sessions provided a high perception of effort.


Assuntos
Percepção/fisiologia , Esforço Físico/fisiologia , Treinamento de Resistência/métodos , Levantamento de Peso/fisiologia , Adulto , Estudos Cross-Over , Feminino , Humanos , Perna (Membro)/fisiologia , Descanso/fisiologia , Fatores de Tempo , Adulto Jovem
10.
PLoS One ; 15(6): e0234507, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32526771

RESUMO

INTRODUCTION: Maximal oxygen uptake ([Formula: see text]) is a measure of cardiorespiratory fitness often used to monitor changes in fitness during and after treatment in cancer patients. There is, however, limited knowledge in how criteria verifying [Formula: see text] work for patients newly diagnosed with cancer. Therefore, the aim of this study was to describe the prevalence of fulfillment of typical criteria verifying [Formula: see text] and to investigate the associations between the criteria and the test leader's evaluation whether a test was performed "to exhaustion". An additional aim was to establish new cut-points within the associated criteria. METHODS: From the Phys-Can randomized controlled trial, 535 patients (59 ±12 years) newly diagnosed with breast (79%), prostate (17%) or colorectal cancer (4%) performed an incremental [Formula: see text] test on a treadmill. The test was performed before starting (neo-)adjuvant treatment and an exercise intervention. Fulfillment of different cut-points within typical criteria verifying [Formula: see text] was described. The dependent key variables included in the initial bivariate analysis were achievement of a [Formula: see text] plateau, peak values for maximal heart rate, respiratory exchange ratio (RER), the patients' rating of perceived exertion on Borg's scale6-20 and peak breathing frequency (fR). A receiver operating characteristic analysis was performed to establish cut-points for variables associated with the test leader's evaluation. Last, a cross-validation of the cut-points found in the receiver operating characteristic analysis was performed on a comparable sample of cancer patients (n = 80). RESULTS: The criteria RERpeak (<0.001), Borg's RPE (<0.001) and fR peak (p = 0.018) were associated with the test leader's evaluation of whether a test was defined as "to exhaustion". The cut-points that best predicted the test leader's evaluation were RER ≥ 1.14, RPE ≥ 18 and fR ≥ 40. Maximal heart rate and [Formula: see text] plateau was not associated with the test leader's evaluation. CONCLUSION: We recommend a focus on RER (in the range between ≥1.1 and ≥1.15) and RPE (≥17 or ≥18) in addition to the test leader's evaluation. Additionally, a fR peak of ≥40 breaths/min may be a cut-point to help the test leader evaluate the degree of exhaustion. However, more research is needed to verify our findings, and to investigate how these criteria will work within a population that are undergoing or finished with cancer treatment.


Assuntos
Aptidão Cardiorrespiratória/fisiologia , Teste de Esforço/métodos , Terapia por Exercício , Neoplasias/reabilitação , Oxigênio/análise , Idoso , Estudos de Coortes , Feminino , Frequência Cardíaca/fisiologia , Humanos , Masculino , Pessoa de Meia-Idade , Neoplasias/diagnóstico , Neoplasias/fisiopatologia , Oxigênio/metabolismo , Consumo de Oxigênio , Esforço Físico/fisiologia , Curva ROC , Valores de Referência , Resultado do Tratamento
11.
Int J Sports Med ; 41(11): 790-797, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32599641

RESUMO

This study compared the effects of two supervised concurrent training interventions in breast cancer survivors with cancer-related fatigue at baseline. Twenty-three female breast cancer survivors (50±8 years) were randomized to a high- (n=13) or a moderate-intensity (n=10) training program. Both interventions lasted 16 weeks and included the same resistance exercises, but the aerobic component was supervised and more intense in the former (i.e., rating of perceived exertion of 7-8 vs. 6 on a 1-10 scale for the high and moderate-intensity intervention, respectively). The primary endpoint was fatigue perception. Endpoints were assessed at baseline and after 16 weeks. The p-value for statistical significance was set at 0.004 after Bonferroni correction for multiple comparisons. The high-intensity training program increased lower-limb muscle strength significantly (p=0.002) and tended to improve fatigue perception (p=0.006), waist circumference (p=0.013), neutrophil-to-lymphocyte ratio (p=0.028) and some quality of life items (p=0.011). Although the moderate-intensity training program did not provide such benefits in general (i.e., higher p-values for pre vs post-intervention comparisons), no significant differences were found between interventions (all p>0.004). Further research is needed to elucidate if the benefits provided by high-intensity concurrent training are superior to those elicited by moderate-intensity training in breast cancer survivors.


Assuntos
Neoplasias da Mama/complicações , Sobreviventes de Câncer , Terapia por Exercício/métodos , Fadiga/terapia , Treinamento Intervalado de Alta Intensidade , Antropometria , Biomarcadores/sangue , Composição Corporal , Aptidão Cardiorrespiratória , Fadiga/etiologia , Feminino , Humanos , Extremidade Inferior/fisiologia , Pessoa de Meia-Idade , Força Muscular/fisiologia , Percepção/fisiologia , Esforço Físico/fisiologia , Qualidade de Vida , Treinamento de Resistência
12.
Phys Ther ; 100(9): 1434-1443, 2020 08 31.
Artigo em Inglês | MEDLINE | ID: mdl-32494824

RESUMO

OBJECTIVE: The benefits of aerobic exercise early after stroke are well known, but concerns about cardiovascular risk are a barrier to clinical implementation. Symptom-limited exercise testing with electrocardiography (ECG) is recommended but not always feasible. The purpose of this study was to determine the frequency of and corresponding exercise intensities at which ECG abnormalities occurred during submaximal exercise testing that would limit safe exercise prescription beyond those intensities. METHODS: This study was a retrospective analysis of ECGs from 195 patients who completed submaximal exercise testing during stroke rehabilitation. A graded submaximal exercise test was conducted with a 5- or 12-lead ECG and was terminated on the basis of predetermined endpoint criteria (heart rate, perceived exertion, signs, or symptoms). ECGs were retrospectively reviewed for exercise-induced abnormalities and their associated heart rates. RESULTS: The peak heart rate achieved was 65.4% (SD = 10.5%) of the predicted maximum heart rate or 29.1% (SD = 15.5%) of the heart rate reserve (adjusted for beta-blocker medications). The test was terminated more often because of perceived exertion (93/195) than because of heart rate limits (60/195). Four patients (2.1%) exhibited exercise-induced horizontal or downsloping ST segment depression of ≥1 mm. Except for 1 patient, the heart rate at test termination was comparable with the heart rate associated with the onset of the ECG abnormality. CONCLUSION: A graded submaximal exercise test without ECG but with symptom monitoring and conservative heart rate and perceived exertion endpoints may facilitate safe exercise intensities early after stroke. Symptom-limited exercise testing with ECG is still recommended when progressing to higher intensity exercise. IMPACT: Concerns about cardiovascular risk are a barrier to physical therapists implementing aerobic exercise in stroke rehabilitation. This study showed that, in the absence of access to exercise testing with ECG, submaximal testing with conservative heart rate and perceived exertion endpoints and symptom monitoring can support physical therapists in the safe prescription of aerobic exercise early after stroke. LAY SUMMARY: It is recommended that people with stroke participate in aerobic exercise as early as possible during their rehabilitation. A submaximal exercise test with monitoring of heart rate, perceived exertion, blood pressure, and symptoms can support physical therapists in safely prescribing that exercise.


Assuntos
Teste de Esforço/métodos , Exercício Físico/fisiologia , Frequência Cardíaca/fisiologia , Segurança do Paciente/normas , Reabilitação do Acidente Vascular Cerebral , Acidente Vascular Cerebral/fisiopatologia , Antagonistas Adrenérgicos beta/uso terapêutico , Adulto , Idoso , Idoso de 80 Anos ou mais , Eletrocardiografia , Teste de Esforço/efeitos adversos , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Esforço Físico/fisiologia , Estudos Retrospectivos , Adulto Jovem
13.
J Sport Health Sci ; 9(3): 258-264, 2020 05.
Artigo em Inglês | MEDLINE | ID: mdl-32444150

RESUMO

BACKGROUND: Q-Factor (QF), or the inter-pedal width, in cycling is similar to step-width in gait. Although increased step-width has been shown to reduce peak knee abduction moment (KAbM), no studies have examined the biomechanical effects of increased QF in cycling at different workrates in healthy participants. METHODS: A total of 16 healthy participants (8 males, 8 females, age: 22.4 ± 2.6 years, body mass index: 22.78 ± 1.43 kg/m2, mean ± SD) participated. A motion capture system and customized instrumented pedals were used to collect 3-dimensional kinematic (240 Hz) and pedal reaction force (PRF) (1200 Hz) data in 12 testing conditions: 4 QF conditions-Q1 (15.0 cm), Q2 (19.2 cm), Q3 (23.4 cm), and Q4 (27.6 cm)-under 3 workrate conditions-80 watts (W), 120 W, and 160 W. A 3 × 4 (QF × workrate) repeated measures of analysis of variance were performed to analyze differences among conditions (p < 0.05). RESULTS: Increased QF increased peak KAbM by 47%, 56%, and 56% from Q1 to Q4 at each respective workrate. Mediolateral PRF increased from Q1 to Q4 at each respective workrate. Frontal-plane knee angle and range of motion decreased with increased QF. No changes were observed for peak vertical PRF, knee extension moment, sagittal plane peak knee joint angles, or range of motion. CONCLUSION: Increased QF increased peak KAbM, suggesting increased medial compartment loading of the knee. QF modulation may influence frontal-plane joint loading when using stationary cycling for exercise or rehabilitation purposes.


Assuntos
Ciclismo/fisiologia , Articulação do Joelho/fisiologia , Equipamentos Esportivos , Artralgia/fisiopatologia , Fenômenos Biomecânicos , Desenho de Equipamento , Feminino , Humanos , Masculino , Percepção/fisiologia , Esforço Físico/fisiologia , Amplitude de Movimento Articular , Estudos de Tempo e Movimento , Adulto Jovem
14.
Int J Sports Med ; 41(10): 677-681, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32455455

RESUMO

This study assessed the internal and external workload of starters and non-starters in a professional top-level soccer team during a congested fixture period. Twenty Serie A soccer players were monitored in this study during two mesocycles of 21 days each. Starters and non-starters were divided based on the match time played in each mesocycle. The following metrics were recorded: exposure time, total distance, relative total distance, high-speed running distance over 20 km·h-1, very high-speed running distance over 25 km·h-1, individual very high-speed distance over 80% of maximum peak speed, and rating of perceived exertion. Differences between starters and non-starters were found for: exposure time (effect size=large to very large), rating of perceived exertion (large to very large), total distance (large to very large), and individual very high-speed distance over 80% of maximum peak speed (moderate to large). Furthermore, differences for relative total distance, high-speed running distance over 20 km·h-1 and very high-speed running distance over 25 km·h-1 were small to moderate, but not significant. This study reports that during congested fixture periods, starters had higher exposure time, rating of perceived exertion, total distance, and individual very high-speed distance over 80% of maximum peak speed than non-starters.


Assuntos
Comportamento Competitivo/fisiologia , Futebol/fisiologia , Adulto , Humanos , Percepção/fisiologia , Condicionamento Físico Humano/fisiologia , Esforço Físico/fisiologia , Corrida/fisiologia , Adulto Jovem
15.
J Sports Sci ; 38(14): 1674-1681, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32314673

RESUMO

This study examined the relative contribution of exercise duration and intensity to team-sport athlete's training load. Male, professional rugby league (n = 10) and union (n = 22) players were monitored over 6- and 52-week training periods, respectively. Whole-session (load) and per-minute (intensity) metrics were monitored (league: session rating of perceived exertion training load [sRPE-TL], individualised training impulse, total distance, BodyLoad™; union: sRPE-TL, total distance, high-speed running distance, PlayerLoad™). Separate principal component analyses were conducted on the load and intensity measures to consolidate raw data into principal components (PC, k = 4). The first load PC captured 70% and 74% of the total variance in the rugby league and rugby union datasets, respectively. Multiple linear regression subsequently revealed that session duration explained 73% and 57% of the variance in first load PC, respectively, while the four intensity PCs explained an additional 24% and 34%, respectively. Across two professional rugby training programmes, the majority of the variability in training load measures was explained by session duration (~60-70%), while a smaller proportion was explained by session intensity (~30%). When modelling the training load, training intensity and duration should be disaggregated to better account for their between-session variability.


Assuntos
Futebol Americano/fisiologia , Condicionamento Físico Humano/métodos , Adulto , Humanos , Modelos Lineares , Masculino , Percepção/fisiologia , Esforço Físico/fisiologia , Análise de Componente Principal , Corrida/fisiologia , Fatores de Tempo
16.
Int J Sports Physiol Perform ; 15(5): 603-616, 2020 05 01.
Artigo em Inglês | MEDLINE | ID: mdl-32294618

RESUMO

PURPOSE: To systematically quantify the external and internal workloads reported during games-based drills in basketball and identify the effects of different modifiable factors on the workloads encountered. METHODS: PubMed, Scopus, MEDLINE, and SPORTDiscus databases were searched for original research published up until January 2, 2019. The search included terms relevant to workload, games-based drills, and basketball. Studies were screened using predefined selection criteria, and methodological quality was assessed prior to data extraction. RESULTS: The electronic search yielded 8,284 studies with 3,411 duplicates. A total of 17 studies met the inclusion criteria for this review, with quality scores ranging from 9 to 10 out of 11. Factors regularly modified during games-based drills among the included studies were team size, playing area, playing and rest time, and game alterations. Games-based drills containing smaller team sizes elicited greater external and internal workloads compared to larger team sizes. Furthermore, full-court games-based drills elicited greater external and internal workloads compared to half-court drills, while continuous games-based drills elicited greater internal workloads compared to intermittent drills. CONCLUSIONS: This review provides a comprehensive collation of data indicating the external and internal workloads reported during different games-based drills in various samples of basketball players. Furthermore, evidence is provided for basketball coaches to consider when prescribing games-based drills and modifying factors during drills across the season. Current literature suggests that smaller team sizes and full-court playing areas elicit greater external and internal workloads than larger team sizes and half-court drills, respectively. Furthermore, continuous games-based drills elicit greater internal workloads than intermittent drills.


Assuntos
Basquetebol/fisiologia , Esforço Físico/fisiologia , Frequência Cardíaca/fisiologia , Humanos , Percepção/fisiologia , Condicionamento Físico Humano/métodos
17.
J Sports Sci ; 38(10): 1124-1131, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-32228154

RESUMO

Identifying the external training load variables which influence subjective internal response will help reduce the mismatch between coach-intended and athlete-perceived training intensity. Therefore, this study aimed to reduce external training load measures into distinct principal components (PCs), plot internal training response (quantified via session Rating of Perceived Exertion [sRPE]) against the identified PCs and investigate how the prescription of PCs influences subjective internal training response. Twenty-nine school to international level youth athletes wore microtechnology units for field-based training sessions. SRPE was collected post-session and assigned to the microtechnology unit data for the corresponding training session. 198 rugby union, 145 field hockey and 142 soccer observations were analysed. The external training variables were reduced to two PCs for each sport cumulatively explaining 91%, 96% and 91% of sRPE variance in rugby union, field hockey and soccer, respectively. However, when internal response was plotted against the PCs, the lack of separation between low-, moderate- and high-intensity training sessions precluded further analysis as the prescription of the PCs do not appear to distinguish subjective session intensity. A coach may therefore wish to consider the multitude of physiological, psychological and environmental factors which influence sRPE alongside external training load prescription.


Assuntos
Percepção/fisiologia , Condicionamento Físico Humano/psicologia , Esforço Físico/fisiologia , Esportes Juvenis/psicologia , Adolescente , Feminino , Monitores de Aptidão Física , Futebol Americano/psicologia , Hóquei/psicologia , Humanos , Estudos Longitudinais , Masculino , Condicionamento Físico Humano/fisiologia , Análise de Componente Principal , Estudos Prospectivos , Futebol/psicologia , Esportes Juvenis/fisiologia
18.
Am J Cardiol ; 125(11): 1751-1752, 2020 06 01.
Artigo em Inglês | MEDLINE | ID: mdl-32279837

RESUMO

In a 27-year-old man the electrocardiogram suggests increased vagal tone, and not intrinsic atrioventricular nodal disease, as the cause of transient atrioventricular block.


Assuntos
Bloqueio Atrioventricular/fisiopatologia , Nervo Vago/fisiopatologia , Adulto , Nó Atrioventricular/fisiopatologia , Eletrocardiografia , Eletrocardiografia Ambulatorial , Humanos , Masculino , Esforço Físico/fisiologia , Síncope
19.
Int J Sports Med ; 41(9): 603-609, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32252101

RESUMO

The ergogenic effect of caffeine is well established, although no investigations providing a high carbohydrate feeding strategy (pre-exercise meal=2 g/kg BM) co-ingested with caffeine exist for soccer. This investigation examines the effect of caffeine in addition to a pre-exercise carbohydrate meal and drink mid-way through a soccer simulation. Eight recreational soccer players completed an 85-minute soccer simulation followed by an exercise capacity test (Yo-yo Intermittent Endurance test level 2) on two occasions. Prior to exercise participants consumed a high carbohydrate meal, with placebo or 5 mg/kg BM-1 caffeine. No significant performance effect was identified (p=0.099) despite a 12.8% (109 m) improvement in exercise capacity following caffeine. Rates of carbohydrate and fat oxidation did not differ between conditions and nor were differences apparent for plasma glucose, fatty acids, glycerol, ß-hydroxybutyrate (p>0.05). However, an increase in lactate was observed for caffeine (p=0.039). A significant condition effect on rating of perceived exertion was identified (p<0.001), with the overall mean for the protocol lowered to 11.7±0.9 au for caffeine compared to 12.8±1.3 au. Caffeine supplementation with a carbohydrate feeding strategy failed to affect metabolic and metabolite responses, although reductions in perception of exercise were observed. While a 12.8% increase in exercise capacity was noted the findings were not significant, possibly due to the small sample size.


Assuntos
Desempenho Atlético/fisiologia , Cafeína/administração & dosagem , Dieta da Carga de Carboidratos , Exercício Físico/fisiologia , Substâncias para Melhoria do Desempenho/administração & dosagem , Futebol/fisiologia , Ácido 3-Hidroxibutírico/sangue , Glicemia/metabolismo , Carboidratos da Dieta/sangue , Método Duplo-Cego , Metabolismo Energético , Ácidos Graxos/sangue , Glicerol/sangue , Humanos , Ácido Láctico/sangue , Masculino , Percepção/fisiologia , Esforço Físico/fisiologia , Adulto Jovem
20.
Int J Sports Physiol Perform ; 15(6): 884-891, 2020 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-32244223

RESUMO

PURPOSE: To investigate how self-selected pole length (PL) of ∼84% (PL84%) compared with ∼90% (PL90%) of body height influenced performance during a 700-m time trial with undulating terrain on snow. METHODS: Twenty-one cross-country skiers, 7 of whom were women, performed 4 trials at a maximal effort in a counterbalanced fashion with PL84% and PL90% separated by 20-minute breaks between trials. In trials I and II, only double poling was allowed, while in trials III and IV, skiers used self-selected classical subtechniques. Continuous speed, cyclic parameters, and heart rate were collected using microsensors in addition to a post-time-trial rating of perceived exertion (RPE). RESULTS: The 700-m times with only double poling were significantly shorter with PL90% than PL84% (mean ± 95% confidence limits -1.6% ± 1.0%). Segment analyses showed higher speed with PL90% in uphill sections than with PL84% (3.7% ± 2.1%), with the greatest difference found for the female skiers (5.6% ± 2.9%). In contrast, on flat terrain at high skiing speeds, speed was reduced with PL90% compared with PL84% (-1.5% ± 1.4%); this was only significant for the male skiers. During free choice of classical subtechniques, PL did not influence performance in any segments, choice of subtechnique, or cycle rate during the trials. No differences in rating of perceived exertion or heart rate between PLs were found. CONCLUSIONS: PL90% improved performance in uphills at low speeds when using double poling but hindered performance on flat terrain and at higher speeds compared with self-selected PLs. Choice of PL should, therefore, be based on racecourse topography, preferred subtechniques, and the skier's physiological and technical abilities.


Assuntos
Desempenho Atlético/fisiologia , Esqui/fisiologia , Equipamentos Esportivos , Estatura , Feminino , Frequência Cardíaca/fisiologia , Humanos , Masculino , Destreza Motora/fisiologia , Percepção/fisiologia , Esforço Físico/fisiologia , Fatores Sexuais , Neve , Análise e Desempenho de Tarefas , Adulto Jovem
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