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2.
Physiol Behav ; 213: 112687, 2020 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-31622613

RESUMO

Reduced exertion high intensity interval training (REHIT) is an extremely low-volume approach of sprint interval exercise (SIE) that increases maximal oxygen uptake (VO2max) and reduces body fat. However, there are concerns regarding implementation of SIE including REHIT in untrained populations due to generation of supramaximal power outputs and potential feelings of displeasure. This study examined perceptual responses to a single REHIT session in adults with above (n = 43, VO2max = 41 ±â€¯6 mL/kg/min) and below average VO2max (n = 42, VO2max = 33 ±â€¯5 mL/kg/min). Initially, incremental exercise was completed to determine VO2max. Subsequently, participants completed REHIT consisting of two 20 s "all-out" sprints at resistance equal to 5 % body mass. Rating of perceived exertion (RPE), affective valence, and physical activity enjoyment (PACES) were determined. Tolerance and preference to exercise intensity were also measured to examine if they moderated the responses. Compared to participants with below average VO2max, those with above average VO2max revealed similar change in affective valence (p = 0.86), RPE (p = 0.41), and enjoyment (p = 0.64) despite attaining significantly higher peak and mean power output in response to REHIT. The lowest value of affective valence ranged from 1.0-1.5, representing "fairly good." Overall, one session of REHIT elicits positive affective valence and similar pleasure:displeasure and enjoyment responses in individuals having diverse cardiorespiratory fitness, although we recommend that REHIT should be individualized for each client as greater frequency of aversive responses was shown in our participants with low fitness.

3.
J Int Soc Sports Nutr ; 16(1): 50, 2019 Nov 07.
Artigo em Inglês | MEDLINE | ID: mdl-31699159

RESUMO

Background In this Position Statement, the International Society of Sports Nutrition (ISSN) provides an objective and critical review of the literature pertinent to nutritional considerations for training and racing in single-stage ultra-marathon. Recommendations for Training. i) Ultra-marathon runners should aim to meet the caloric demands of training by following an individualized and periodized strategy, comprising a varied, food-first approach; ii) Athletes should plan and implement their nutrition strategy with sufficient time to permit adaptations that enhance fat oxidative capacity; iii) The evidence overwhelmingly supports the inclusion of a moderate-to-high carbohydrate diet (i.e., ~ 60% of energy intake, 5-8 g·kg- 1·d- 1) to mitigate the negative effects of chronic, training-induced glycogen depletion; iv) Limiting carbohydrate intake before selected low-intensity sessions, and/or moderating daily carbohydrate intake, may enhance mitochondrial function and fat oxidative capacity. Nevertheless, this approach may compromise performance during high-intensity efforts; v) Protein intakes of ~ 1.6 g·kg- 1·d- 1 are necessary to maintain lean mass and support recovery from training, but amounts up to 2.5 g.kg- 1·d- 1 may be warranted during demanding training when calorie requirements are greater; Recommendations for Racing. vi) To attenuate caloric deficits, runners should aim to consume 150-400 Kcal·h- 1 (carbohydrate, 30-50 g·h- 1; protein, 5-10 g·h- 1) from a variety of calorie-dense foods. Consideration must be given to food palatability, individual tolerance, and the increased preference for savory foods in longer races; vii) Fluid volumes of 450-750 mL·h- 1 (~ 150-250 mL every 20 min) are recommended during racing. To minimize the likelihood of hyponatraemia, electrolytes (mainly sodium) may be needed in concentrations greater than that provided by most commercial products (i.e., > 575 mg·L- 1 sodium). Fluid and electrolyte requirements will be elevated when running in hot and/or humid conditions; viii) Evidence supports progressive gut-training and/or low-FODMAP diets (fermentable oligosaccharide, disaccharide, monosaccharide and polyol) to alleviate symptoms of gastrointestinal distress during racing; ix) The evidence in support of ketogenic diets and/or ketone esters to improve ultra-marathon performance is lacking, with further research warranted; x) Evidence supports the strategic use of caffeine to sustain performance in the latter stages of racing, particularly when sleep deprivation may compromise athlete safety.


Assuntos
Carboidratos da Dieta/administração & dosagem , Ingestão de Energia , Necessidades Nutricionais , Corrida/fisiologia , Fenômenos Fisiológicos da Nutrição Esportiva , Atletas , Desempenho Atlético , Comportamento Competitivo , Proteínas na Dieta/administração & dosagem , Humanos , Resistência Física , Corrida/classificação , Sociedades
4.
Biol Sport ; 36(3): 225-231, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31624416

RESUMO

The present study examined the effect of meal intake on physiological and psychological indices during self-selected high intensity interval exercise (HIIE). Seventeen active men and women (age = 26.4 ± 5.8 yr) completed ramp cycle ergometry to determine maximal oxygen uptake and peak power output. On two subsequent days, they performed a session of self-selected HIIE consisting of ten 1 min bouts separated by 1 min recovery in the fed or fasted state, whose order was randomized. Meal intake consisted of a banana and a Zone™ bar containing 315 kcal, which were ingested 2 h pre-exercise, and the fasted state required no food for > 12 h pre-exercise. Participants ingested an identical meal the evening before each session. Heart rate (HR), oxygen uptake (VO2), blood glucose and blood lactate concentration, rating of perceived exertion (RPE), affect, and enjoyment were measured during exercise. Irrespective of fed state, both bouts elicited intensities equal to 94% HRmax which represents HIIE. Our results showed no difference in HR (174.0 ± 13.5 vs. 173.2 ± 12.9 b/min in fed and fasted state, p = 0.17), VO2 (2.43 ± 0.54 vs. 2.40 ± 0.52 L/min in fed and fasted state, p = 0.14), RPE (p = 0.44), affect (p = 0.79), or enjoyment (103 ± 14 vs. 101 ± 13, p = 0.77) between the fed and fasted state. Despite its high reliance on carbohydrate, performance and perception of low-volume HIIE are not altered by ingestion of a meal before exercise.

5.
Artigo em Inglês | MEDLINE | ID: mdl-31395812

RESUMO

BACKGROUND: There is individual responsiveness to exercise training as not all individuals experience increases in maximal oxygen uptake (VO2max), which does not benefit health status considering the association between VO2max and mortality. Approximately 50% of the training response is genetic, with the other 50% accounted for by variations in dietary intake, sleep, recovery, and the metabolic stress of training. This study examined if the blood lactate (BLa) response to high intensity interval training (HIIT) as well as habitual dietary intake and sleep duration are associated with the resultant change in VO2max (ΔVO2max). METHODS: Fourteen individuals (age and VO2max = 27 ± 8 years and 38 ± 4 mL/kg/min, respectively) performed nine sessions of HIIT at 130% ventilatory threshold. BLa was measured during the first and last session of training. In addition, sleep duration and energy intake were assessed. RESULTS: Data showed that VO2max increased with HIIT (p = 0.007). No associations occurred between ΔVO2max and BLa (r = 0.44, p = 0.10), energy intake (r = 0.38, p = 0.18), or sleep duration (r = 0.14, p = 0.62). However, there was a significant association between training heart rate (HR) and ΔVO2max (r = 0.62, p = 0.02). CONCLUSIONS: When HIIT is prescribed according to a metabolic threshold, energy intake, sleep status, and BLa do not predict ΔVO2max, yet the HR response to training is associated with the ΔVO2max.


Assuntos
Aptidão Cardiorrespiratória , Treinamento Intervalado de Alta Intensidade , Ácido Láctico/sangue , Adulto , Ingestão de Energia , Exercício/fisiologia , Feminino , Frequência Cardíaca/fisiologia , Humanos , Masculino , Consumo de Oxigênio/fisiologia , Adulto Jovem
6.
Int J Exerc Sci ; 12(2): 602-613, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31156742

RESUMO

Nutritional status has numerous effects on exercise metabolism and psychological responses. The effect of fed state on changes in affective valence; however, are unknown. Thus, the present study examined how fed state influenced self-selected exercise intensity, affective responses during exercise, and exercise enjoyment when exercise was completed following physical activity guidelines for public health. In a repeated-measures crossover design, 25 recreationally active men and women (age and BMI = 22.0 ± 2.0 yr and 24.3 ± 3.3 kg/m2) performed a single 30 min session of treadmill exercise at a Rating of Perceived Exertion (RPE) equal to 13 on the Borg 6-20 scale following an overnight fast (FAST) or 30 minutes after a small meal (FED). Affective valence was recorded every 3 minutes during exercise. Heart rate and gas exchange data were measured continuously using a metabolic cart, blood glucose and blood lactate concentration were measured pre/post-exercise, and enjoyment was measured 15 minutes post-exercise. There was no effect of condition on affective valence, enjoyment, or self-selected intensity (all p>0.05). However, pre-exercise blood glucose was higher in FED pre-exercise, but higher post-exercise in FAST (p<0.05). Blood lactate concentration was also higher in FAST (p<0.05). Our results reveal minimal effects of a small, high-carbohydrate pre-exercise meal on in-task and post-task affective responses, exercise enjoyment, and self-selected intensity. These data suggest that an overnight fast does not alter affective valence or reduce enjoyment of continuous exercise.

7.
Eur J Sport Sci ; 19(10): 1377-1385, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31092118

RESUMO

This study examined changes in enjoyment, affective valence, and rating of perceived exertion (RPE) in obese women performing two regimes of high intensity interval training (HIIT) differing in structure and volume. Nineteen obese and inactive women (age and body mass index = 37.5 ± 10.5 yr and 39.0 ± 4.3 kg/m2) were randomized to 6 wk of traditional (TRAD, n = 10) or periodized interval training (PER, n = 9) which was performed on a cycle ergometer during which structure changed weekly. Two supervised sessions per week were performed in a lab, and one session per week was performed unsupervised. During every lab-based session, perceptual responses including enjoyment, affective valence, and RPE were acquired. Data showed a groupXtraining interaction for enjoyment (p = 0.02) which was lower by 10-25 units during PER versus TRAD. In addition, there was a groupXtimeXtraining interaction for RPE (p = 0.01). RPE did not change in response to TRAD yet varied during PER, with lower RPE values exhibited during brief supramaximal bouts (6.3 ± 0.9) compared to longer intervals (7.3 ± 1.2). Both regimes showed reductions in affective valence during training, with the lowest values equal to 1.5 ± 1.6 in TRAD and -0.2 ± 1.6 in PER. Compared to TRAD, more aversive responses were shown in PER throughout training by 0.4-2.0 units. Data show lower enjoyment and more aversive responses to higher-volume bouts of interval training, which suggests that shorter bouts may be perceived more favourably by obese women.


Assuntos
Afeto , Treinamento Intervalado de Alta Intensidade/psicologia , Obesidade/terapia , Prazer , Adulto , Feminino , Treinamento Intervalado de Alta Intensidade/métodos , Humanos , Pessoa de Meia-Idade
8.
Physiol Behav ; 204: 27-32, 2019 05 15.
Artigo em Inglês | MEDLINE | ID: mdl-30738970

RESUMO

High intensity interval exercise (HIIE) is identified as an alternative to moderate intensity continuous exercise (MICE) due to its similar effects on outcomes including maximal oxygen uptake and glycemic control. Nevertheless, its widespread implementation in adults is questioned because acute HIIE elicits more aversive responses (negative affective valence) than MICE which may make it impractical to perform long-term. Differences in muscle mass, fiber type, and substrate utilization exist between men and women that alter physiological responses which may cause differences in affective valence, yet the effect of sex on this outcome is unresolved. This study compared changes in affective valence between active men and women (mean age = 24.0 ±â€¯4.8 yr) performing HIIE and sprint interval exercise (SIE) on a cycle ergometer. Affect (+5 to -5), rating of perceived exertion (RPE 1-10), and blood lactate concentration (BLa) were measured before and throughout exercise, and enjoyment was assessed post-exercise. Results showed that women exhibit more positive affect (p < .05) during HIIE and SIE than men (0.6-1.8 units higher values). In addition, women exhibited lower BLa (p = .003) than men during SIE (11.8 ±â€¯2.4 mM vs. 14.9 ±â€¯3.1 mM). In contrast, there was no effect of sex on RPE (p = .32 and p = .54) or enjoyment (p = .24 and p = .37) in response to HIIE or SIE. Practitioners should consider the sex of their clients when assessing change in affective valence induced by interval-based exercise.

9.
Eur J Appl Physiol ; 119(4): 879-888, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30643959

RESUMO

PURPOSE: We determined the effects of two high-intensity interval training (HIIT) regimens [the traditional (TRAD) and periodized (PER)] on changes in maximal oxygen uptake (VO2max), body composition, and muscular strength in sedentary, obese women. METHODS: Seventeen women (age and BMI = 37.5 ± 10.5 year and 39.1 ± 4.3 kg/m2) were randomized into a 6 week regime of TRAD or PER which consisted of three sessions per week, two in the laboratory, and one on their own. Pre- and post-training, VO2max, body composition, and muscular strength of the knee extensors (KE) and flexors (KF) were assessed via ramp cycling to exhaustion, air displacement plethysmography, and isokinetic dynamometry, respectively. RESULTS: VO2max was increased by 4-5% in response to training (p = 0.045) with no group-by-time interaction (p = 0.79). Body mass, fat mass, and waist-to-hip ratio were unaltered (p > 0.05) in response to training, yet there was a significant change in percent body fat (p = 0.03), percent fat-free mass (p = 0.03), and absolute fat-free mass (p = 0.03) in TRAD but not PER. No change occurred in KE (p = 0.36) or KF torque (p = 0.75) in response to training and there was no group-by-time interaction (p > 0.05). CONCLUSIONS: Low-volume HIIT improved VO2max and body composition but did not modify muscular strength, which suggests that obese women desiring to increase strength should initiate more intense HIIT or partake in formal resistance training.


Assuntos
Composição Corporal/fisiologia , Força Muscular/fisiologia , Obesidade/metabolismo , Consumo de Oxigênio/fisiologia , Adulto , Feminino , Treinamento Intervalado de Alta Intensidade/métodos , Humanos , Masculino , Obesidade/fisiopatologia , Oxigênio/metabolismo , Treinamento de Resistência , Análise e Desempenho de Tarefas
10.
Artigo em Inglês | MEDLINE | ID: mdl-30675386

RESUMO

Study design: Repeated measures within-subjects crossover study. Objectives: High intensity interval exercise (HIIE) elicits higher oxygen consumption (VO2) and heart rate (HR) versus moderate intensity continuous exercise (MICE) in men with spinal cord injury (SCI). No study has compared hemodynamic responses to HIIE versus MICE in SCI. In this study, we determined hemodynamic and cardiorespiratory responses to different bouts of arm cycling in men with SCI. Setting: Human Performance Laboratory, San Diego, CA. Methods: Five men (age and injury duration = 42.6 ± 16.1 yr and 9.9 ± 7.6 yr) with SCI participated in the study. VO2peak and peak power output were initially assessed. Subsequent visits included MICE, HIIE, sprint interval exercise (SIE), and a no-exercise control (CON). Energy expenditure was matched across modes and equal to 100 ± 10 kcal. During the bouts, cardiac output (CO), stroke volume (SV), HR, and VO2 were measured. Results: Heart rate, SV, and CO increased in response to all exercise bouts and were higher during exercise versus CON. During HIIE and SIE, heart rate approached 90% of maximum, and stroke volume increased by 40% which was higher (p < 0.05) versus MICE and CON. In addition, exercise led to a two (MICE) to threefold increase in CO (HIIE and SIE) although it was not different from CON. VO2 during SIE and HIIE was higher (p < 0.05) versus MICE. Conclusions: Similar to results in non-disabled populations, HIIE and SIE elicit near-maximal values of SV and CO.

11.
J Strength Cond Res ; 33(11): 2945-2952, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-29742746

RESUMO

Kellogg, E, Cantacessi, C, McNamer, O, Holmes, H, von Bargen, R, Ramirez, R, Gallagher, D, Vargas, S, Santia, B, Rodriguez, K, and Astorino, TA. Comparison of psychological and physiological responses to imposed vs. self-selected high-intensity interval training. J Strength Cond Res 33(11): 2945-2952, 2019-High-intensity interval training elicits similar physiological adaptations as moderate intensity continuous training (MICT). Some studies report greater enjoyment to a bout of high-intensity interval exercise (HIIE) vs. MICT, which is surprising considering that HIIE is more intense and typically imposed on the participant. This study compared physiological and perceptual responses between imposed and self-selected HIIE. Fourteen adults (age = 24 ± 3 years) unfamiliar with HIIE initially performed ramp exercise to exhaustion to measure maximal oxygen uptake (VO2max) followed by 2 subsequent sessions whose order was randomized. Imposed HIIE consisted of eight 60 seconds bouts at 80 percent peak power output (%PPO) separated by 60 seconds recovery at 10 %PPO. Self-selected HIIE (HIIESS) followed the same structure, but participants freely selected intensity in increments of 10 %PPO to achieve a rating of perceived exertion (RPE) ≥7. During exercise, heart rate, VO2, blood lactate concentration (BLa), affect (+5 to -5), and RPE were assessed. Physical Activity Enjoyment Scale was measured after exercise. Results showed higher VO2 (+10%, p = 0.013), BLa (p = 0.001), and RPE (p = 0.001) in HIIESS vs. HIIEIMP, and lower affect (p = 0.01), and enjoyment (87.6 ± 15.7 vs. 95.7 ± 11.7, p = 0.04). There was a significantly higher power output in self-selected vs. imposed HIIE (263.9 ± 81.4 W vs. 225.2 ± 59.6 W, p < 0.001). Data suggest that intensity mediates affective responses rather than the mode of HIIE performed by the participant.


Assuntos
Exercício/fisiologia , Exercício/psicologia , Treinamento Intervalado de Alta Intensidade , Adaptação Fisiológica , Adulto , Afeto , Frequência Cardíaca , Humanos , Ácido Láctico/sangue , Masculino , Consumo de Oxigênio , Prazer , Adulto Jovem
12.
J Spinal Cord Med ; 42(4): 494-501, 2019 07.
Artigo em Inglês | MEDLINE | ID: mdl-29355464

RESUMO

Context/Objective: Maximal oxygen uptake (VO2max) is a widely used measure of cardiorespiratory fitness, aerobic function, and overall health risk. Although VO2max has been measured for almost 100 yr, no standardized criteria exist to verify VO2max attainment. Studies document that incidence of 'true' VO2max obtained from incremental exercise (INC) can be confirmed using a subsequent verification test (VER). In this study, we examined efficacy of VER in persons with spinal cord injury (SCI).Design: Repeated measures, within-subjects study.Setting: University laboratory in San Diego, CA.Participants: Ten individuals (age and injury duration = 33.3 ± 10.5 yr and 6.8 ± 6.2 yr) with SCI and 10 able-bodied (AB) individuals (age = 24.1 ± 7.4 yr).Interventions: Peak oxygen uptake (VO2peak) was determined during INC on an arm ergometer followed by VER at 105 percent of peak power output (% PPO).Outcome Measures: Gas exchange data, heart rate (HR), and blood lactate concentration (BLa) were measured during exercise.Results: Across all participants, VO2peak was highly related between protocols (ICC = 0.98) and the mean difference was equal to 0.08 ± 0.11 L/min. Compared to INC, VO2peak from VER was not different in SCI (1.30 ± 0.45 L/min vs. 1.31 ± 0.43 L/min) but higher in AB (1.63 ± 0.40 L/min vs. 1.76 ± 0.40 L/min).Conclusion: Data show similar VO2peak between incremental and verification tests in SCI, suggesting that VER confirms VO2max attainment. However, in AB participants completing arm ergometry, VER is essential to validate appearance of 'true' VO2peak.

13.
Physiol Behav ; 196: 211-217, 2018 11 01.
Artigo em Inglês | MEDLINE | ID: mdl-30170171

RESUMO

Affect is typically positive at intensities below the lactate or ventilatory threshold, yet more aversive responses occur at supra-threshold intensities which may reduce positive perceptions of exercise. Completion of high intensity interval exercise (HIIE) typically elicits a reduction in affect, yet greater post-exercise enjoyment has been reported in response to HIIE versus moderate intensity continuous exercise (MICE). This study examined affectual responses to HIIE and sprint interval exercise (SIE) in 71 active men and women (age = 24.0 ±â€¯4.8 year). Participants performed various HIIE and SIE regimes on the cycle ergometer during which affect (+5 - -5 scale), rating of perceived exertion (RPE, Borg 1-10 scale), and blood lactate concentration (BLa) were determined. Enjoyment was measured post-exercise using the PACES scale. Predictors of change in these variables in response to exercise were identified using multiple regression. Results showed a significant reduction in affect (p = .001) which was greater (p = .03) with SIE (-5.7 ±â€¯2.7) compared to HIIE (-4.3 ±â€¯2.4). Nevertheless, there was marked variability in the affect response across participants, as its change ranged from -1 to -7 units from pre- to post-exercise in 85% of all sessions. Sixty two percent of the change in affect seen across regimes was explained by baseline affect, BLa, and enjoyment. Significant associations were shown between the change in affect and baseline affect (r = -0.46, p < .001) and change in RPE (r = -0.59, p < .001). In addition, RPE significantly increased in response to HIIE (6.1 ±â€¯1.7) and SIE (6.9 ±â€¯2.0) but was not different (p = .050) between regimes. Our findings document an intensity-dependent relationship between affect and intensity during interval training, as supramaximal intensities elicit a larger decline in affect compared to submaximal intensities. In addition, pre-exercise affect is associated with the magnitude of change in affect reported in response to interval exercise.


Assuntos
Afeto , Treinamento Intervalado de Alta Intensidade/métodos , Treinamento Intervalado de Alta Intensidade/psicologia , Afeto/fisiologia , Feminino , Humanos , Ácido Láctico/sangue , Masculino , Percepção , Caracteres Sexuais , Adulto Jovem
14.
Eur J Appl Physiol ; 118(9): 1811-1820, 2018 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-29923111

RESUMO

Completion of high-intensity interval training (HIIT) leads to significant increases in maximal oxygen uptake (VO2max) and oxidative capacity. However, individual responses to HIIT have been identified as approximately 20-40% of individuals show no change in VO2max, which may be due to the relatively homogeneous approach to implementing HIIT. PURPOSE: This study tested the effects of HIIT prescribed using ventilatory threshold (VT) on changes in VO2max and cycling performance. METHODS: Fourteen active men and women (age and VO2max = 27 ± 8 year and 38 ± 4 mL/kg/min) underwent nine sessions of HIIT, and 14 additional men and women (age and VO2max = 22 ± 3 year and 40 ± 5 mL/kg/min) served as controls. Training was performed on a cycle ergometer at a work rate equal to 130%VT and consisted of eight to ten 1 min bouts interspersed with 75 s of recovery. At baseline and post-testing, they completed progressive cycling to exhaustion to determine VO2max, and on a separate day, a 5 mile cycling time trial. RESULTS: Compared to the control group, HIIT led to significant increases in VO2max (6%, p = 0.007), cycling performance (2.5%, p = 0.003), and absolute VT (9 W, p = 0.005). However, only 57% of participants revealed meaningful increases in VO2max and cycling performance in response to training, and two showed no change in either outcome. CONCLUSIONS: A greater volume of HIIT may be needed to maximize the training response for all individuals.


Assuntos
Ciclismo/fisiologia , Consumo de Oxigênio/fisiologia , Adolescente , Adulto , Feminino , Frequência Cardíaca/fisiologia , Treinamento Intervalado de Alta Intensidade/métodos , Humanos , Masculino , Pessoa de Meia-Idade , Oxigênio/metabolismo , Adulto Jovem
15.
J Sex Med ; 15(6): 888-893, 2018 06.
Artigo em Inglês | MEDLINE | ID: mdl-29753800

RESUMO

BACKGROUND: Sex has been deemed taboo for athletic performance going back to ancient Rome and Greece, as the act of sex was thought to promote ease and a sense of relaxation. AIM: This study examined the effect of sexual intercourse completed 12 hours before a bout of isokinetic dynamometry on muscle force production in strength-trained men. METHODS: 12 Healthy physically active men (age = 25.6 ± 3.8 years) who were sexually active participated in this study. After men completed a familiarization session on day 1, muscle force was measured during 5 sets of maximal unilateral knee extension (KE) and knee flexion exercise at 30 deg/s after men engaged in or abstained from sexual intercourse within the previous 12 hours. The order of this treatment was randomized across participants, and time of day was maintained across all sessions. OUTCOMES: Lower extremity muscle strength and endurance were measured. RESULTS: Data showed no significant effect (P = .34 and P = .39) of sexual intercourse on peak or average KE or knee flexion torque. For example, after sexual intercourse, KE torque was similar in set 1 (198.9 ± 39.1 ft/lb vs 190.2 ± 28.7 ft/lb) and set 5 (163.2 ± 30.8 ft/lb vs 159.4 ± 35.2 ft/lb) compared to when men abstained from sexual intercourse. CLINICAL TRANSLATION: Engaging in sexual intercourse on the night before exercise is not detrimental to muscular strength in active men. CONCLUSIONS: This study is strengthened by use of a homogeneous sample of active men as well as precise determination of changes in muscle function via isokinetic dynamometry. However, completion of sexual intercourse was confirmed through self-report rather than direct observation, so it is not certain if participants actually met the requirements of each condition. Results demonstrate that sexual intercourse does not significantly impact lower extremity muscle force, which suggests that restricting sexual activity before short-term, high-force activity is unnecessary. Valenti LM, Suchil C, Beltran G, et al. Effect of Sexual Intercourse on Lower Extremity Muscle Force in Strength-Trained Men. J Sex Med 2018;15:888-893.


Assuntos
Coito/fisiologia , Força Muscular/fisiologia , Músculo Esquelético/fisiologia , Torque , Adulto , Feminino , Grécia , Humanos , Articulação do Joelho/fisiologia , Extremidade Inferior/fisiologia , Masculino , Treinamento de Resistência , Adulto Jovem
16.
Clin Physiol Funct Imaging ; 38(4): 703-709, 2018 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-28940974

RESUMO

Although maximal oxygen uptake (VO2 max) has been measured for almost 100 years, it is unknown when 'true' VO2 max is attained. Primary (the VO2 plateau) and secondary criteria are used to confirm VO2 max incidence, but frequency of the VO2 plateau varies, and secondary criteria are relatively invalid. The verification test (VER) seems to elicit similar estimates of VO2 max versus the incremental value (INC), yet existing data are limited by small populations and use of inadequate criteria to confirm 'true' VO2 max. We investigated the efficacy of VER by analysing data from 109 participants who underwent INC followed by VER at 105% or 110% of peak power output (PPO). Differences in VO2 max between VER and INC were analysed, and intraclass correlation coefficient (ICC), standard error of the mean (SEM) and minimum difference (MD) were computed. Results showed that VO2 max was significantly higher (2%, P<0·05) in INC versus VER, VO2 max was highly related between protocols (ICC = 0·99) and SEM and MD were low. However, 11% of participants did not reveal 'true' VO2 max as the verification value was higher than INC by 3·0% - 3·3%. Fitness level altered the difference in VO2 max between INC and VER in study one, as lower fitness individuals showed a larger difference in VO2 max between protocols, although gender did not affect the difference in VO2 max between protocols. Our data show that VER does not verify 'true' VO2 max in all individuals, which may be related to their fitness level.


Assuntos
Teste de Esforço , Tolerância ao Exercício , Contração Muscular , Músculo Esquelético/fisiologia , Consumo de Oxigênio , Adolescente , Adulto , Ciclismo , Aptidão Cardiorrespiratória , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Valor Preditivo dos Testes , Reprodutibilidade dos Testes , Estudos Retrospectivos , Fatores de Tempo , Adulto Jovem
17.
J Sports Med Phys Fitness ; 58(7-8): 1052-1062, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-28639441

RESUMO

BACKGROUND: High intensity interval training (HIIT) increases maximal oxygen uptake similar to aerobic exercise. However, changes in body composition are equivocal in response to HIIT. We examined changes in body composition and dietary restraint in response to 20 sessions of HIIT varying in structure. METHODS: Thirty nine active men and women (age and VO2max=22.5±4.4 years and 40.1±5.6 mL/kg/min) were randomized to one of three periodized HIIT regimes performed on a cycle ergometer. Before and after training, body composition was assessed using skinfolds (SKF), circumference measures, and Bioelectrical Impedance Analysis (BIA) following standardized procedures. Hunger, restraint, and disinhibition were also measured using the 3-Factor Eating Questionnaire and Power of Food Survey. Control participants (N.=32, age and VO2max=25.6±4.4 years and 40.6±4.9 mL/kg/min) matched for age and fitness level underwent all testing but did not complete HIIT. RESULTS: There was no change (P>0.05) in body mass, circumferences, or BIA-derived body fat in response to HIIT. However, SKF-derived body fat declined (P=0.04) with HIIT, and gender x time (P=0.03) and gender x time x regimen interactions (P=0.04) were shown in that women but not men exhibited significant reductions in body fat. Hunger was reduced from baseline to post-training (P=0.028), but this response was not different in response to HIIT compared to controls. CONCLUSIONS: Twenty sessions of low-volume HIIT reduce body fat in women but not men, but do not alter perceptions of hunger.


Assuntos
Tecido Adiposo/fisiologia , Treinamento Intervalado de Alta Intensidade/métodos , Fome/fisiologia , Adulto , Atitude , Feminino , Treinamento Intervalado de Alta Intensidade/psicologia , Humanos , Masculino , Pregas Cutâneas , Adulto Jovem
18.
J Strength Cond Res ; 32(8): 2130-2138, 2018 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-28737586

RESUMO

Olney, N, Wertz, T, LaPorta, Z, Mora, A, Serbas, J, and Astorino, TA. Comparison of acute physiological and psychological responses between moderate-intensity continuous exercise and three regimes of high intensity interval training. J Strength Cond Res 32(8): 2130-2138, 2018-High-intensity interval training (HIIT) elicits similar physiological adaptations as moderate-intensity continuous training (MICT) despite less time commitment. However, there is debate whether HIIT is more aversive than MICT. This study compared physiological and perceptual responses between MICT and 3 regimes of HIIT. Nineteen active adults (age = 24.0 ± 3.3 years) unfamiliar with HIIT initially performed ramp exercise to exhaustion to measure maximal oxygen uptake (V[Combining Dot Above]O2max) and determine workload for subsequent sessions, whose order was randomized. Sprint interval training (SIT) consisted of six 20-second bouts of "all-out" cycling at 140% of maximum watts (Wmax). Low-volume HIIT (HIITLV) and high-volume HIIT (HIITHV) consisted of eight 60-second bouts at 85% Wmax and six 2-minute bouts at 70% Wmax, respectively. Moderate-intensity continuous training consisted of 25 minutes at 40% Wmax. Across regimes, work was not matched. Heart rate (HR), V[Combining Dot Above]O2, blood lactate concentration (BLa), affect, and rating of perceived exertion (RPE) were assessed during exercise. Ten minutes postexercise, Physical Activity Enjoyment (PACES) was measured via a survey. Results revealed significantly higher (p ≤ 0.05) V[Combining Dot Above]O2, HR, BLa, and RPE in SIT, HIITLV, and HIITHV vs. MICT. Despite a decline in affect during exercise (p < 0.01) and significantly lower affect (p ≤ 0.05) during all HIIT regimes vs. MICT at 50, 75, and 100% of session duration, PACES was similar across regimes (p = 0.65), although it was higher in women (p = 0.03). Findings from healthy adults unaccustomed to interval training demonstrate that HIIT and SIT are perceived as enjoyable as MICT despite being more aversive.


Assuntos
Adaptação Fisiológica/fisiologia , Treinamento Intervalado de Alta Intensidade/métodos , Treinamento Intervalado de Alta Intensidade/psicologia , Adulto , Feminino , Frequência Cardíaca/fisiologia , Humanos , Ácido Láctico/sangue , Masculino , Consumo de Oxigênio/fisiologia , Percepção , Adulto Jovem
19.
J Sports Med Phys Fitness ; 58(1-2): 164-171, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-27391412

RESUMO

BACKGROUND: Increases in maximal oxygen uptake (VO2max) are widely reported in response to completion of high intensity interval training (HIIT), yet the mechanism explaining this result is poorly understood. This study examined changes in VO2max and cardiac output (CO) in response to 10 sessions of low-volume HIIT. METHODS: Participants included 30 active men and women (mean age and VO2max=22.9±5.4 years and 39.6±5.6 mL/kg/min) who performed HIIT and 30 men and women (age and VO2max=25.7±4.5 years and 40.7±5.2 mL/kg/min) who served as non-exercising controls (CON). High intensity interval training consisted of 6-10 s bouts of cycling per session at 90-110 percent peak power output (PPO) interspersed with 75 s recovery. Before and after training, progressive cycling to exhaustion was completed during which CO, stroke volume (SV), and heart rate (HR) were estimated using thoracic impedance. To confirm VO2max attainment, a verification test was completed after progressive cycling at a work rate equal to 110%PPO. RESULTS: Data demonstrated significant improvements in VO2max (2.71±0.63 L/min to 2.86±0.63 L/min, P<0.001) and COmax (20.0±3.1 L/min to 21.7±3.2 L/min, P=0.04) via HIIT that were not exhibited in CON. Maximal SV was increased in HIIT (P=0.04) although there was no change in maximal HR (P=0.57). CONCLUSIONS: The increase in VO2max seen in response to ten sessions of HIIT is due to improvements in oxygen delivery.


Assuntos
Débito Cardíaco , Treinamento Intervalado de Alta Intensidade , Oxigênio/metabolismo , Adolescente , Adulto , Feminino , Coração/fisiologia , Frequência Cardíaca , Humanos , Masculino , Consumo de Oxigênio , Adulto Jovem
20.
J Spinal Cord Med ; 41(1): 77-84, 2018 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-27808004

RESUMO

BACKGROUND: High intensity interval training (HIIT) is a robust and time-efficient approach to improve multiple health indices including maximal oxygen uptake (VO2max). Despite the intense nature of HIIT, data in untrained adults report greater enjoyment of HIIT versus continuous exercise (CEX). However, this has yet to be investigated in persons with spinal cord injury (SCI). OBJECTIVE: To examine differences in enjoyment in response to CEX and HIIT in persons with SCI. DESIGN: Repeated measures, within-subjects design. SETTING: University laboratory in San Diego, CA. PARTICIPANTS: Nine habitually active men and women (age = 33.3 ± 10.5 years) with chronic SCI. INTERVENTION: Participants performed progressive arm ergometry to volitional exhaustion to determine VO2peak. During subsequent sessions, they completed CEX, sprint interval training (SIT), or HIIT in randomized order. OUTCOME MEASURES: Physical activity enjoyment (PACES), affect, rating of perceived exertion (RPE), VO2, and blood lactate concentration (BLa) were measured. RESULTS: Despite a higher VO2, RPE, and BLa consequent with HIIT and SIT (P < 0.05), PACES was significantly higher (P = 0.03) in response to HIIT (107.4 ± 13.4) and SIT (103.7 ± 12.5) compared to CEX (81.6 ± 25.4). Fifty-five percent of participants preferred HIIT and 45% preferred SIT, with none identifying CEX as their preferred exercise mode. CONCLUSION: Compared to CEX, brief sessions of submaximal or supramaximal interval training elicit higher enjoyment despite higher metabolic strain. The long-term efficacy and feasibility of HIIT in this population should be explored considering that it is not viewed as more aversive than CEX.


Assuntos
Treinamento Intervalado de Alta Intensidade/psicologia , Reabilitação Neurológica/psicologia , Prazer , Traumatismos da Medula Espinal/psicologia , Adulto , Feminino , Treinamento Intervalado de Alta Intensidade/métodos , Humanos , Masculino , Pessoa de Meia-Idade , Reabilitação Neurológica/métodos , Consumo de Oxigênio , Distribuição Aleatória , Traumatismos da Medula Espinal/fisiopatologia , Traumatismos da Medula Espinal/reabilitação
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