We propose that physiological and performance tests used in sport science research and professional practice should be developed following a rigorous validation process, as is done in other scientific fields, such as clinimetrics, an area of research that focuses on the quality of clinical measurement and uses methods derived from psychometrics. In this commentary, we briefly review some of the attributes that must be explored when validating a test: the conceptual model, validity, reliability, and responsiveness. Examples from the sport science literature are provided.
Franco M. Impellizzeri and Samuele M. Marcora
Alister McCormick, Carla Meijen, and Samuele Marcora
This study examined the effects of strategic, motivational self-talk for runners completing a 60-mile, overnight ultramarathon using a randomized, controlled experiment. Data were collected before, during, and after an annual ultramarathon. Twenty-nine ultramarathon runners were randomly allocated to a motivational self-talk group or an alternative control group. A condition-by-time mixed ANOVA indicated that learning to use motivational self-talk did not affect preevent self-efficacy or perceived control. A t-test and magnitude-based inference indicated that motivational self-talk did not affect performance. Nevertheless, follow-up data suggested that most participants found the intervention helpful and continued to use it six months after their research commitment, particularly in endurance events and to a lesser extent in training. Participants continued to use self-talk to cope with exertion, as well as other stressors such as blister discomfort and adverse conditions. Suggestions are offered for future research examining the effects of psychological interventions on performance in endurance events.
Franco M. Impellizzeri, Samuele M. Marcora, and Aaron J. Coutts
Exercise is a stressor that induces various psychophysiological responses, which mediate cellular adaptations in many organ systems. To maximize this adaptive response, coaches and scientists need to control the stress applied to the athlete at the individual level. To achieve this, precise control and manipulation of the training load are required. In 2003, the authors introduced a theoretical framework to define and conceptualize the measurable constructs of the training process. They described training load as having 2 measurable components: internal and external load. The aim of this commentary is to extend, clarify, and refine both the theoretical framework and the definitions of internal and external training load to avoid misinterpretation of this concept.
Hawkar S. Ahmed, Samuele M. Marcora, David Dixon, and Glen Davison
Context: Referees’ physical and cognitive performance are important for successful officiating in team sports. There is a lack of research on cognitive performance of referees in general, and none in futsal. Purpose: To assess referees’ performance on the psychomotor vigilance task (PVT) before and after competitive futsal matches during the Football Association (FA) National Futsal League 2015/16. Methods: Fourteen futsal referees (mean [SD] age 34.3 [10.0] y) from the FA National Futsal group were included. The referees were required to undertake a 10-min PVT 60 min before the match kickoff time (pretest) and immediately after matches (posttest). They also completed the Brunel Mood Scale (BRUMS) questionnaire before the prematch PVT and after the postmatch PVT. Result: Data were analyzed by paired t tests comparing prematch and postmatch results. There was a significant difference in BRUMS parameters vigor (9.5 [2.5] prematch vs 6.3 [2.4] postmatch, P = .001) and fatigue (1.4 [1.3] prematch vs 5.6 [3.1] postmatch, P < .001). However, PVT performance was significantly improved (mean reaction time 248.3 [26.2] ms prematch vs 239.7 [22.4] ms postmatch, P = .023). Conclusions: The present results show, contrary to the authors’ initial hypothesis, that psychomotor performance is improved as opposed to decreased after a single match. The postmatch improvement suggests that exercise can acutely enhance cognitive performance, which could be used to inform warm-up practices (eg, optimal duration and intensity) geared toward optimizing referees’ cognitive performance during matches.
Carla Meijen, Alister McCormick, Paul A. Anstiss, and Samuele M. Marcora
There is potential in delivering brief, educational interventions online, particularly for recreational athletes. This initial investigation examined how two online interventions were perceived by endurance participants and how they affected outcomes of interest. After measuring self-efficacy, 142 people were randomized to one of three groups (self-talk, implementation intentions, and control) before an endurance event. Ninety-four completed postevent measures, which were self-efficacy, goal attainment, performance satisfaction, coping, stress appraisals, and social validity. The interventions involved approximately 10 min of initial engagement with online material. Perceptions of stress controllability were significantly higher in the implementation intention group compared with the control. There were no other statistically significant effects. Nevertheless, both intervention groups were satisfied with their interventions, found them useful, and were planning to continue using them. The findings demonstrate the feasibility and value of using brief, online psychological interventions, which may be timely in our changing profession, as COVID-19 has moved many interventions online.
Chiara Gattoni, Michele Girardi, Barry Vincent O’Neill, and Samuele Maria Marcora
Purpose: Sleep deprivation (SD) is very common during ultraendurance competitions. At present, stimulants such as caffeine and naps are the main strategies used to reduce the negative effects of SD on ultraendurance performance. In this case study, the authors describe the application of a novel strategy consisting of the intermittent repetition of SD (SD training [SDT]) during the weeks preceding an ultraendurance competition. Methods: A male ultraendurance runner underwent a 6-week SDT program (consisting of 1 night SD every Sunday) in addition to his regular physical training program before taking part in a 6-day race. Before and after SDT, the participant performed 5 consecutive days of daily 2-hour constant-pace running with SD on the first and third night. Psychological and physiological responses were measured during this multiday test. Results: SDT was well tolerated by the athlete. A visual analysis of the data suggests that including SDT in the weeks preceding an ultraendurance competition may have beneficial effects on sleepiness and perceived mental effort in the context of 5 consecutive days of prolonged running and 2 nights of SD. This multiday test seems a feasible way for assessing ultraendurance athletes in the laboratory. Conclusions: The results provided some encouraging initial information about SDT that needs to be confirmed in a randomized controlled trial in a group of ultraendurance athletes. If confirmed to be effective and well tolerated, SDT might be used in the future to help ultraendurance athletes and other populations that have to perform in conditions of SD.
Luca Angius, Michele Merlini, James Hopker, Mattia Bianchi, Francesco Fois, Francesco Piras, Paolo Cugia, James Russell, and Samuele Maria Marcora
Purpose : Professional football players experience both physical and mental fatigue (MF). The main aims of this randomized crossover study were to investigate the effect of MF on repeated-sprint ability (RSA) and the effects of both physical fatigue and MF on psychomotor vigilance. Methods: Seventeen male professional football players performed 10 maximal 20-m shuttle sprints interspaced by incomplete recovery (RSA test). Running speed, heart rate, brain oxygenation, and rating of perceived exertion were monitored during each sprint. The RSA test was preceded by either a 30-minute Stroop task to induce MF or by watching a documentary for 30 minutes (control [CON]) in a randomized counterbalanced order. Participants performed a psychomotor vigilance test at baseline, after the cognitive task (MF or CON), and after the RSA test. Results: Heart rate and rating of perceived exertion significantly increased, while running speed and brain oxygenation significantly decreased over the repeated sprints (P < .001) with no significant differences between conditions. Response speed during the psychomotor vigilance test significantly declined after the Stroop task but not after CON (P = .001). Response speed during the psychomotor vigilance test declined after the RSA test in both conditions (P < .001) and remained lower in the MF condition compared to CON (P = .012). Conclusions: MF does not reduce RSA. However, the results of this study suggest that physical fatigue and MF have negative and cumulative effects on psychomotor vigilance. Therefore, strategies to reduce both physical fatigue and MF should be implemented in professional football players.