Reliability of the Heartbeat Tracking Task to Assess Interoception.

Interoception refers to the competence in perceiving and interpreting internal sensations emerging from the body. The most common approach to assess interoception is through cardiac interoceptive tests like the heartbeat tracking task (HTT), which measures the accuracy on perceive and counting heartbeats during a period. However, the literature is scarce in providing adequate reliability evidence for this measure so that the interoception assessment may be threaten. In addition to HTT accuracy, it is possible to determine sensibility (self-reported confidence) and interoceptive awareness (correspondence between accuracy and sensibility). Thus, we measured the test-retest reliability of HTT and also investigated the behavior of HTT outcomes along the task. Therefore, 31 healthy adults (16 males) with 27.8 (9.4) years old performed two consecutive HTT interspersed by one day. Intraclass correlation coefficient (ICC), standard error of measurement (SEM) and minimal detectable difference (MD) analyzes showed 'Good' relative reliability for interoceptive accuracy (ICC = 0.880; SEM = 0.263; MD = 0.728; p < 0.001) and 'Moderate' for sensibility (ICC = 0.617; SEM = 0.648; MD = 1.797; p < 0.001) and awareness (ICC = 0.593; SEM = 0.227; MD = 0.628; p < 0.001). The absolute reliability shows low threshold values for observing true effects in HTT outcomes. The results also showed that reducing the number of HTT blocks did not impact the outcomes. The HTT showed to be reliable in determine the interoceptive competences in healthy adults.

Effects of Self-Selected Passive Recovery Time in Interval Exercise on Perceptual and Heart Rate Responses in Older Women: A Promissory Approach.

The purpose of the study was to investigate the effects of passive recovery with self-selected time on affect, ratings of perceived exertion, and heart rate in self-selected interval exercises (SSIE). Fifteen older women (68.1 ± 3.8 years), weekly practitioners of functional activities participated in three SSIE with self-selected recovery time (SSRT) and one self-selected continuous exercise session, all at 24 min approximately. The SSIE had the following configurations: 1'/SSRT, 1.5'/SSRT, and 2'/SSRT. The results showed that at the beginning of stimulus heart rate in 1.5'/SSRT (107.9 ± 16.5) and 2'/SSRT (114.6 ± 17.1) were significantly greater (p < .05) compared with self-selected continuous exercise (102.8 ± 14.5). The ratings of perceived exertion in self-selected continuous exercise (2.4 ± 0.4; p < .05) were higher compared with SSIE in recovery. No significant differences were found in affect. The SSIE provided similar responses based on recoveries manipulations.

Is There a Dose-Response Relationship between High-Intensity Interval Exercise (HIIE) Intensity and Affective Valence? Analysis of Three HIIE Sessions Performed with Different Amplitudes.

The inverse relationship between exercise intensity and affective valence is well established for continuous exercise but not for high-intensity interval exercise (HIIE). The objective was to verify the dose-response relationship between exercise intensity and affective valence in HIIE sessions. Eleven young men underwent a vigorous-intensity continuous exercise (VICE) and three HIIE sessions at the same average intensity (70% of peak power-WPeak) and duration (20 min) but with different amplitudes: 10 × [1 min at 90% WPeak/1 min at 50% WPeak]-HIIE-90/50; 10 × [1 min at 100% WPeak/1 min at 40% WPeak]-HIIE-100/40; 10 × [1 min at 110% WPeak/1 min at 30% WPeak]-HIIE-110/30. During the exercise sessions, psychophysiological variables were recorded (VO2, VCO2, heart rate, perceived exertion CR10, and Feeling Scale (FS)). Higher correlations were found between CR10 and FS for all conditions (VICE = -0.987; HIIE-90/50 = -0.873; HIIE-100/40 = -0.908; HIIE-110/30 = -0.948). Regarding the physiological variables, the %HRMax presented moderate inverse correlations with FS for all exercise conditions (VICE = -0.867; HIIE-90/50 = -0.818; HIIE-100/40 = -0.837; HIIE-110/30 = -0.828) while the respiratory variables (%VO2Peak and %VCO2Peak) presented low-to-moderate correlations only for VICE, HIIE-90/50, and HIIE-100/40 (ranging from -0.523 to -0.805). Poor correlations were observed between the %VO2Peak (r = -0.293) and %VCO2Peak (r = -0.020) with FS. The results indicated that perceived exertion is more sensible than physiological variables to explain the intensity-affective valence relationship in HIIE sessions. RPE should be used for HIIE prescription with a focus on affect.

Transcranial Direct Current Stimulation Combined With or Without Caffeine: Effects on Training Volume and Pain Perception.

Purpose: This study aimed to investigate the acute effects of tDCS combined with caffeine intake on training volume and pain perception in the bench press in resistance-trained males. The correlation between training volume and pain perception was also assessed in all interventions. Methods: Sixteen healthy males (age = 25.2 ± 4.7 years, body mass = 82.8 ± 9.1 kg, and height = 178.3 ± 5.7 cm), advanced in RT, were randomized and counterbalanced for the following experimental conditions: Sham tDCS with placebo intake (Sham+Pla), Sham tDCS with caffeine intake (Sham+Caff), anodal tDCS with placebo intake (a-tDCS+Pla), and anodal tDCS with caffeine intake (a-tDCS+Caff). The caffeine or placebo ingestion (both with 5 mg.kg-1) occurred 40 minutes before the tDCS sessions. The tDCS was applied over the left DLPFC for 20 minutes, with a 2 mA current intensity. After the tDCS sessions, participants performed the bench press with an 80% of 1RM load, where training volume and pain perception were measured. Results: Training volume was higher in the 1st and 2nd sets in both a-tDCS+Caff and Sham+Caff conditions, compared to the Sham+Pla condition (P < .05). Both a-tDCS+Caff and a-tDCS+Pla showed an increased pain perception during the third set compared to the first set. Also, no correlation was found between the number of repetitions and pain perception in any condition (P > .05). Conclusion: This research revealed that caffeine intake alone could be used as an ergogenic aid during resistance training programs in resistance-trained males.

Proof-of-Concept and Test-Retest Reliability Study of Psychological and Physiological Variables of the Mental Fatigue Paradigm.

This study provided a proof-of-concept and test-retest reliability of measures frequently used to assess a mental fatigue paradigm. After familiarization, 28 healthy men performed (40-min) the Rapid Visual Information Processing (RVP) test in a test-retest design, having mental fatigue sensation, motivation, emotional arousal, total mood disturbance, and electroencephalography (EEG) in the prefrontal cortex measured before and after the test. EEG was recorded during a 3-min rest so that the power spectral density of theta (3-7 Hz) and alpha (8-13 Hz) bands was calculated. Pre-to-post RVP test changes in psychological and physiological domains were compared (paired-T tests), and absolute (standard error of measurement (SEM) and minimal difference (MD)) and relative reliability (intraclass correlation coefficient (ICC)) were calculated. The RVP test induced an increase (p < 0.05) in mental fatigue sensation (120.9% (109.4; 132.4)) and total mood disturbance (3.5% (-6.3; 13.3)), and a decrease in motivation (-7.1% (-9.2; -5.1)) and emotional arousal (-16.2% (-19.1; -13.2)). Likewise, EEG theta (59.1% (33.2; 85.0); p < 0.05), but not alpha band, increased due to RVP test. All psychophysiological responses showed poor-to-moderate relative reliability. Changes in mental fatigue sensation and motivation were higher than SEM and MD, but changes in EEG theta band were higher only than SEM. Mental fatigue sensation, motivation, and EEG theta band were sensitive to distinguish a mental fatigue paradigm despite true mental fatigue effects on theta activity may be trivial.

Comparison of affective responses during school physical education classes with different recovery times / Comparação das respostas afetivas durante aulas de educação física escolar com diferentes tempos de recuperação

ABSTRACT This study aimed to verify the effect of exercise recovery time on the affective responses during a circuit training in physical education classes. Forty-six apparently healthy young adolescents (twenty-one girls) (12.85 ± 0.94 years; 49.7 ± 8.93 kg; 1.59 ± 0.08 cm; 19.51 ± 3.28 kg/m2) participated in this study. Were submitted participants for two physical education classes, based on circuited model of the same intensity, but with different recovery times (2 min and 1 min). The study was carried out in two phases: baseline and intervention. Affect, Arousal, and Ratings of Perceived Exertion data were analyzed using paired t-tests, considering a significance level of p < 0.05. The class with longer rest time (2 min) provided greater affection (t(45) = 3.586; p < 0,001) and less perceived effort (t(45) = 2.295; p = 0,026). The intensity manipulation strategy was effective in providing different affective responses, in which classes perceived as more intense, resulting in the decline of affect.

RESUMO O objetivo do estudo foi verificar o efeito do tempo de recuperação do exercício nas respostas afetivas durante um treinamento em circuito nas aulas de educação física. Quarenta e seis jovens adolescentes aparentemente saudáveis (vinte e uma meninas), com (12.85 ± 0.94 anos; 49.7 ± 8.93 kg; 1.59 ± 0.08 cm; 19.51 ± 3.28 kg/m2), participaram do estudo. Os participantes foram submetidos a duas aulas de educação física escolar, baseados em modelo de circuitos de mesma intensidade, porém com tempos de recuperação diferentes (2 min e 1 min). O estudo foi realizado em duas fases: base e intervenção. Os dados de Afeto, Ativação e Percepção Subjetiva do Esforço, foram analisados através de testes t pareados, considerando um nível de significância de p < 0,05. A aula com maior tempo de descanso (2 min) proporcionou maior afeto (t(45) = 3.586; p < 0,001) e menor esforço percebido (t(45) = 2.295; p = 0,026). A estratégia de manipulação da intensidade foi efetiva para proporcionar respostas afetivas diferentes, em que a aula percebida como mais intensa resultou no declínio do afeto.