1,721,038 research outputs found
May a Nonlocalized Postactivation Performance Enhancement Exist Between the Upper and Lower Body in Trained Men?
Full text linkThe aim of this study was to establish whether a resistance exercise for the upper body may generate a postactivation performance enhancement (PAPE) in the lower body. Thirteen resistance-trained men (age = 26.4 ± 3.3 years, body mass = 76.9 ± 6.3 kg, and height = 177.6 ± 5.2 cm) participated in the present investigation and were tested for upper-body and lower-body power (bench press throw and countermovement jump power [CMJP] tests). Subjects were also tested for maximum force and electromyographic (EMG) activation of quadriceps muscles while performing an isometric leg extension. All assessments were performed before and 8 minutes after a high-intensity (HI: 5 sets of 1 rep at 90% of 1 repetition maximum [1RM]) bench press protocol, a high-power protocol (POW: 5 sets of 1 rep at 30% of 1RM with maximum explosive intent), and a control trial (CON). Subjects performed all trials in a randomized order and on different days. A significant trial × time interaction was detected for CMJP (p = 0.049). This parameter was significantly increased following the HI protocol only (p = 0.024). A significant interaction was also noted for EMG with a significant improvement following the HI protocol (p = 0.032) and a significant decrease following the POW protocol (p = 0.020). No other significant effects were detected (p > 0.05). The results of this investigation indicate that a HI bench press protocol may produce a PAPE in the lower-body power and increase the neuromuscular activation of leg extensor muscles. The POW bench press protocol did not show any positive effects on lower-body performance. Athletes and practitioners may take advantage from the inclusion of upper-body HI resistance exercises throughout complex resistance workouts to improve lower-body power output
Pulsed Electromagnetic Field (PEMF) stimulation as an adjunct to exercise: a brief review
Full text linkPulsed Electromagnetic Field (PEMF) therapy is a non-invasive treatment that utilizes electromagnetic fields to stimulate and promote natural healing processes within the body. PEMF therapy works by emitting low-frequency electromagnetic pulses, which penetrate deep into tissues and cells, enhancing cellular function and health. PEMF applications are vast, ranging from enhancing recovery in athletes to supporting overall well-being in everyday individuals. PEMF therapy is increasingly recognized in the realm of sports and physical activity for its profound benefits in enhancing performance, accelerating recovery, and preventing injuries. By improving circulation, enhancing tissue oxygenation, and promoting the body's natural healing processes, PEMF therapy has become an invaluable tool in sports medicine, contributing to optimized physical health and prolonged athletic careers. In this review, we explore the effects of PEMF on exercise and the underlying physiological mechanisms
Effects of mental fatigue on perception of effort and performance in national level swimmers
Full text linkObjective: This study aimed to investigate the effects of mental fatigue on the perceptual and physiological responses to swimming at the lactate threshold (LT) and on 400-m front-crawl performance. Methods: Ten national-level swimmers were tested three separate times. In the first session, swimmers performed a 7x200-m incremental test for LT assessment. In sessions two and three, participants performed the AX-Continuous Performance Task for 90-min (mental fatigue condition) or rested for 90-min (control condition) in a randomized and counterbalanced order. After the experimental manipulation, the participants performed a 12x100-m constant-speed test at LT followed by a 400-m front-crawl performance test. Fatigue was measured using the Brunel Mood Scale before and after the experimental manipulation. Heart rate (HR), blood lactate concentration (La) and rating of perceived exertion (RPE) were measured during the swimming tests. Generalized Mixed Models were used to test main effects and interactions, and Holm-Bonferroni post-hoc correction was applied when necessary (p < 0.05). Results: Fatigue increased only for the mental fatigue condition (p = 0.018). During the 12 x 100 m constant-speed test at LT, athletes in the mental fatigue condition presented higher RPE (p = 0.001) despite similar HR and La responses compared to control. Performance in the 400-m front-crawl test was significantly impaired in mentally fatigued swimmers (p < 0.001). Conclusion: These findings show that mental fatigue increases the perception of effort during swimming at LT despite no significant physiological alterations and reduces 400-m front-crawl performance in national level swimmers
The effect of mental fatigue on half-marathon performance: a pragmatic trial
No full textPurpose: It is well established that mental fatigue impairs performance during lab-based endurance tests lasting less than 45 min. However, the effects of mental fatigue on longer duration endurance events and in field settings are unknown. The aim of this study was to investigate the effect of mental fatigue on performance during a half-marathon race. Methods: Forty-six male amateur runners (means ± SD: age 43.8 ± 8.6 years, V ̇ O2peak 46.0 ± 4.1 ml/kg/min) completed a half-marathon after being randomly allocated to performing a 50-min mentally fatiguing task (mental fatigue group) or reading magazines for 50 min (control group). Running speed, heart rate, and perceived effort were measured during the race. Results: Runners in the mental fatigue group completed the half-marathon approximately 4 min slower (106.2 ± 12.4 min) than those in the control group (102.4 ± 10.2 min), but this difference was not statistically significant (Cohen’s d = 0.333; p = 0.265). However, equivalence was not established [t(40.88) = 0.239, p = 0.594] and equivalence testing analysis excluded a beneficial effect of mental fatigue on half-marathon performance. Conclusion: Due to its posttest-only design and the achievable sample size, the study did not have enough power to provide evidence that the observed 4-min increase in half-marathon time is statistically significant. However, equivalence testing suggests that mental fatigue has no beneficial effect on half-marathon performance in male amateur runners, and a harmful effect cannot be excluded. Overall, it seems prudent for endurance athletes to avoid mentally fatiguing tasks before competitions
Assessing Cognitive-Motor Interference in Military Contexts: Validity and Reliability of Two Dual-tasking Tests
Full text linkIntroduction
Cognitive-motor interference is the decrease in cognitive performance and/or physical performance occurring when a cognitive task and a physical task are performed concurrently (dual task) compared to when they are performed in isolation (single task). The aim of this study was to investigate the construct validity and test–retest reliability of two cognitive-motor interference tests in military contexts.
Materials and Methods
Twenty-two soldiers, officers, and cadets performed a 10-min loaded marching, a 10-min Psychomotor Vigilance Task, and the two tasks combined (visit 1). During visit 2, a 5-min running time trial, a 5-min Word Recall Task, and the two tasks combined. These tests were repeated by 20 participants after 2 weeks (visits 3 and 4).
Results
Significant impairments were shown on both running distance (P < .001) and number of words recalled (P = .004) in the dual-task condition compared to the single-task condition. Significantly shorter step length (P < .001) and higher step frequency (P < .001) were found during the loaded marching in the dual-task condition compared to the single-task condition. No significant differences were observed in mean reaction time (P = .402) and number of lapses (P = .479) during the Psychomotor Vigilance Task. Good-to-excellent reliability was found for all the cognitive and physical variables in both single- and dual-task conditions, except for the number of lapses.
Conclusion
These findings suggest that the Running + Word Recall Task test is a valid and reliable dual-tasking test that could be used to assess cognitive-motor interference in military contexts
Psychological determinants of whole-body endurance performance
Full text linkBackground: No literature reviews have systematically identified and evaluated research on the psychological determinants of endurance performance, and sport psychology performance-enhancement guidelines for endurance sports are not founded on a systematic appraisal of endurance-specific research.
Objective: A systematic literature review was conducted to identify practical psychological interventions that improve endurance performance and to identify additional psychological factors that affect endurance performance. Additional objectives were to evaluate the research practices of included studies, to suggest theoretical and applied implications, and to guide future research.
Methods: Electronic databases, forward-citation searches, and manual searches of reference lists were used to locate relevant studies. Peer-reviewed studies were included when they chose an experimental or quasi-experimental research design, a psychological manipulation, endurance performance as the dependent variable, and athletes or physically-active, healthy adults as participants.
Results: Consistent support was found for using imagery, self-talk, and goal setting to improve endurance performance, but it is unclear whether learning multiple psychological skills is more beneficial than learning one psychological skill. The results also demonstrated that mental fatigue undermines endurance performance, and verbal encouragement and head-to-head competition can have a beneficial effect. Interventions that influenced perception of effort consistently affected endurance performance.
Conclusions: Psychological skills training could benefit an endurance athlete. Researchers are encouraged to compare different practical psychological interventions, to examine the effects of these interventions for athletes in competition, and to include a placebo control condition or an alternative control treatment. Researchers are also encouraged to explore additional psychological factors that could have a negative effect on endurance performance. Future research should include psychological mediating variables and moderating variables. Implications for theoretical explanations of endurance performance and evidence-based practice are described
The psychobiological model of pacing in endurance performance
Full text linkPacing is the mechanism that athletes use in order to attempt to control their speed in such a manner that they can cover a specific distance or perform in a set time without failing. Several theories and models have been proposed on pacing and the regulation of pacing strategies. The aim of this thesis was to present a new prominent model of endurance performance for pacing, the Psychobiological model for pacing and analyse its single factors.
The Psychobiological model for pacing has based its theory on five factors to explain pacing and performance: i) the perception of effort, defined as “the conscious sensation of how hard, heavy and strenuous the exercise is”; ii) the potential motivation that represents the individual’s willingness to exert effort; iii) the distance- or time trial duration to cover; iv) the time/distance elapsed/remaining and; v) the previous experience/memory of perceived exertion during exercise of varying intensity and duration.
In chapter 2 we elucidated the influence of VO2max during a 30 min running time trial. Results showed that runners of different VO2max, pace themselves using different speed in order to avoid reaching maximal RPE and, thus, exhaustion, before the end of the time trial. However, no difference has been found in pacing strategy which does not depend on VO2max.
In chapter 3 we discussed the effect of knowledge of distance to cover on pacing and performance during a 5 km running time trial. Results showed that knowledge of distance to cover and learning from previous experience is an important determinant in pacing and pacing strategy. Individuals when informed of the correct knowledge of distance to cover where able to pace themselves faster and complete the performance test significantly faster than when the knowledge of distance to cover was incorrectly provided.
In chapter 4 we assessed the effect of knowledge of distance/time remaining on pacing by using a 5 km time trial to account for knowledge of
distance and a 30 min cycling time trial to account for knowledge of time remaining. Results demonstrated that time/distance feedback plays an important role for performance. The significant difference in distance/time to complete the performance test showed that participants who were aware of the remaining time/distance to be covered were able to choose a pace during the time trial compared to when they were blind to the distance/time feedback.
Finally, in chapter 5 we analysed the efficacy of motivational verbal encouragement provided at different phases during a 30 min cycling time trial. Results showed the determinant role of verbal encouragement in relation with RPE and the importance of the timing at which to provide it. Individuals who were verbally encouraged at the end of the cycling performance showed a faster pace and overall they covered a greater distance compared to when they were encouraged at the beginning of the time trial.
Overall, this thesis demonstrated that the psychobiological model of endurance performance for pacing proposed in the recent years is, indeed, a valid and effective model to explain human performance and it provides new insights in the study of pacing, compared to other existing models of pacing
Subjective monitoring of professional soccer players: validation and application using big data analytics
Full text linkThe first aim of the research program reported in this thesis was to develop predictive models of daily and match-related fatigue and investigate the factors associated with subjective recovery in professional soccer players by analysing the commonly used wellness measures. The second aim was to explore the validity and reliability of five single-item scales widely used in research and practice to measure the subjective status of professional soccer players.
In the first study we found, using big data analytics, that daily and match-day fatigue can be predicted with reasonable accuracy in six professional soccer teams monitored throughout the entire season (53,294 observations). This study also shows that psychological factors like stress and mood are important predictors of fatigue (mental fatigue). In the second study of four professional soccer teams (36,381 observations), we found that subjective recovery is primarily associated with fatigue and muscle soreness, and that these variables mediate 55% of the relationship between training load and subjective recovery. Albeit correlative, our findings also suggest that reducing mental fatigue and muscle soreness may help subjective recovery and performance of professional soccer players. In the third study involving 186 Italian soccer players, we investigated the validity and reliability of single-item measures of subjective Fatigue, Sleep Quality, Muscle Soreness, Stress and Mood. Although correlated to their criterion measures, these scales do not show a convergent validity to the criterion measures themselves. In conclusion, these practical and inexpensive single-item scales commonly used to monitor soccer players daily, do not appear to be a valid assessment of the variable they purport to measure
Perceived exertion: metrological approaches and applications to endurance performance in able-bodied and spinal cord injured populations.
Full text linkThe thesis contributes significantly to our understanding of perceived exertion (PE), paving the way for further investigation. By rectifying metrological issues, providing nuanced findings, and acknowledging limitations, it offers a foundation for future research in exercise science and sports performance.
Endurance training leads whether to improve performance and reduce PE, whether to impaired performance and a concurrent increase in the PE, or modifying either performance or PE with a specificity of training adaptation observed in relation to the modality of training used. PE reflects any psychophysiological stimuli that can affect performance. Through this lens, we can understand its relevance observed in our systematic review regarding the adaptation to any modification in fitness level. Hence, with the aim to monitor endurance training-induced adaptations, analyzing the PE with a method of production, estimation, or ratio is then a major addition.
Chapter 2 presents a pivotal metrological inquiry, uncovering a fundamental scientific error that has persisted for over six decades. This discovery challenges the validity of numerous studies in the field of PE and guides a reevaluation of subjective measurement methods. By addressing this error, the thesis establishes a scientific framework for accurately assessing PE in various interventions.
The subsequent sections of the thesis apply these insights in practical settings. The research explores novel aspects of PE, particularly its kinetics and relationship with physiological responses. Special attention is given to high-level athletes with spinal cord injuries, offering unique insights into their psychophysiological responses to exercise and longitudinal monitoring.
In summary, the thesis advances our understanding of PE by rectifying metrological errors, providing nuanced findings, and applying scientific rigor to subjective measurement methods. It underscores the importance of PE in training adaptations and offers valuable insights into the experiences of athletes with spinal cord injuries
Psychological load related to training and competitions in athletes: validity and reliability of new differential RPE scales
No full textThe purpose of this PhD thesis was to begin the validation process of two RPE-based scales that separate the psychological load of a training session from the physical one. Five different studies were conducted with more than two hundred semi-professional and élite athletes. The two new differential RPE scales, the perceived mental exertion rating scale (M-RPE) and the perceived physical exertion sclae (P-RPE), results valid compared to the criterion measure, able to discriminate different mental and physical training loads in field and in laboratory environment, and very reliable with athletes on the field. Finally, the ecological validity of the two scales was tested in a pilot study in which 4 professional and semi-professional teams were monitored differentiating the perceived effort experienced by athletes during training and competitions. The results of this multiple research studies support the use of differential RPE scales in the daily practice of monitoring the training loads of individual and team sports athletes. Finally we provided reliable and ecologically valid measures of physical and mental loads in different types of training and competition
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