Mental fatigue is conceptualized as a psychobiological state induced by sustained periods of demanding cognitive activity and characterized by feelings of tiredness and lack of energy ( 5 , 17 ). The adverse effects of mental fatigue on cognitive performance have been extensively reported ( 15 , 33
Eduardo Macedo Penna, Edson Filho, Samuel Penna Wanner, Bruno Teobaldo Campos, Gabriel Resende Quinan, Thiago Teixeira Mendes, Mitchell Robert Smith and Luciano Sales Prado
Susan Vrijkotte, Romain Meeusen, Cloe Vandervaeren, Luk Buyse, Jeroen van Cutsem, Nathalie Pattyn and Bart Roelands
longer. 1 NFO and OTS are the result of a disbalance between training and recovery. Both psychological and physiological factors interact to create distress that can result in physical and mental fatigue. 2 Meeusen et al 1 , 3 developed a 2-bout exercise protocol for diagnosing NFO and OTS. The 2-bout
Denver M.Y. Brown and Steven R. Bray
mental fatigue also revealed a medium to large effect ( d = 0.74) of mental fatigue on subsequent self-control task performance ( Clarkson, Otto, Hassey, & Hirt, 2016 ). Baumeister and Vohs ( 2016 ) suggest that heightened perceptions of mental fatigue may be indicative of depleted resources (i.e., ego
Kristy Martin, Kevin G. Thompson, Richard Keegan and Ben Rattray
Mental fatigue is a change in psychobiological state caused by prolonged periods of demanding cognitive activity ( Marcora, Staiano, & Manning, 2009 ). Aside from the detrimental effect of mental fatigue on cognition ( Boksem, Meijman, & Lorist, 2005 , 2006 ; Van der Linden, Frese, & Meijman
Oliver O. Badin, Mitchell R. Smith, Daniele Conte and Aaron J. Coutts
To assess the effects of mental fatigue on physical and technical performance in small-sided soccer games.
Twenty soccer players (age 17.8 ± 1.0 y, height 179 ± 5 cm, body mass 72.4 ± 6.8 kg, playing experience 8.3 ± 1.4 y) from an Australian National Premier League soccer club volunteered to participate in this randomized crossover investigation. Participants played 15-min 5-vs-5 small-sided games (SSGs) without goalkeepers on 2 occasions separated by 1 wk. Before the SSG, 1 team watched a 30-min emotionally neutral documentary (control), while the other performed 30 min of a computer-based Stroop task (mental fatigue). Subjective ratings of mental and physical fatigue were recorded before and after treatment and after the SSG. Motivation was assessed before treatment and SSG; mental effort was assessed after treatment and SSG. Player activity profiles and heart rate (HR) were measured throughout the SSG, whereas ratings of perceived exertion (RPEs) were recorded before the SSG and immediately after each half. Video recordings of the SSG allowed for notational analysis of technical variables.
Subjective ratings of mental fatigue and effort were higher after the Stroop task, whereas motivation for the upcoming SSG was similar between conditions. HR during the SSG was possibly higher in the control condition, whereas RPE was likely higher in the mental-fatigue condition. Mental fatigue had an unclear effect on most physical-performance variables but impaired most technical-performance variables.
Mental fatigue impairs technical but not physical performance in small-sided soccer games.
Manuel D. Quinones and Peter W.R. Lemon
Hydrothermally modified non-genetically modified organisms corn starch (HMS) ingestion may enhance endurance exercise performance via sparing carbohydrate oxidation. To determine whether similar effects occur with high-intensity intermittent exercise, we investigated the effects of HMS ingestion prior to and at halftime on soccer skill performance and repeated sprint ability during the later stages of a simulated soccer match. In total, 11 male university varsity soccer players (height = 177.7 ± 6.8 cm, body mass = 77.3 ± 7.9 kg, age = 22 ± 3 years, body fat = 12.8 ± 4.9%, and maximal oxygen uptake = 57.1 ± 3.9 ml·kg BM−1·min−1) completed the match with HMS (8% carbohydrate containing a total of 0.7 g·kg BM−1·hr−1; 2.8 kcal·kg BM−1·hr−1) or isoenergetic dextrose. Blood glucose was lower (p < .001) with HMS at 15 min (5.3 vs. 7.7 mmol/L) and 30 min (5.6 vs. 8.3 mmol/L) following ingestion, there were no treatment differences in blood lactate, and the respiratory exchange ratio was lower with HMS at 15 min (0.84 vs. 0.86, p = .003); 30 min (0.83 vs. 0.85, p = .004); and 45 min (0.83 vs. 0.85, p = .007) of the first half. Repeated sprint performance was similar for both treatments (p > .05). Soccer dribbling time was slower with isoenergetic dextrose versus baseline (15.63 vs. 14.43 s, p < .05) but not so with HMS (15.04 vs. 14.43 s, p > .05). Furthermore, during the passing test, penalty time was reduced (4.27 vs. 7.73 s, p = .004) with HMS. During situations where glycogen availability is expected to become limiting, HMS ingestion prematch and at halftime could attenuate the decline in skill performance often seen late in contests.
Robert J. Kowalsky, Sophy J. Perdomo, John M. Taormina, Christopher E. Kline, Andrea L. Hergenroeder, Jeffrey R. Balzer, John M. Jakicic and Bethany Barone Gibbs
period. 21 Therefore, we examined the acute (same day) effect of alternating between sitting and standing postures every 30 minutes in a simulated office setting and over a full workday on subjective levels of discomfort, physical fatigue, mental fatigue, and sleepiness. We hypothesized that using a sit
Nils Haller, Tobias Ehlert, Sebastian Schmidt, David Ochmann, Björn Sterzing, Franz Grus and Perikles Simon
assessed by a visual analog scale (VAS) questionnaire, which included football-specific items such as general perceived exertion, muscular, and mental fatigue. Rate of perceived exertion (RPE)–based methods have been suggested as a reliable tool for player load in previous studies. 17 Moreover, acute
Darren J. Paul, Paul S. Bradley and George P. Nassis
Time-motion analysis is a valuable data-collection technique used to quantify the match running performance of elite soccer players. However, interpreting the reductions in running performance in the 2nd half or temporarily after the most intense period of games is highly complex, as it could be attributed to physical or mental fatigue, pacing strategies, contextual factors, or a combination of mutually inclusive factors. Given that research in this domain typically uses a reductionist approach whereby match running performance is examined in isolation without integrating other factors, this ultimately leads to a 1-dimensional insight into match performance. Subsequently, a cohesive review of influencing factors does not yet exist. The aim of this commentary is to provide a detailed insight into the complexity of match running performance and its most influential factors.
Thomas B. Walker and Robert A. Robergs
Rhodiola rosea is an herb purported to possess adaptogenic and ergogenic properties and has recently been the subject of increased interest. The purpose of this article was to review and summarize recent investigations of the potential performance-enhancing properties of Rhodiola rosea. Such studies have generated equivocal results. Several investigations conducted in Eastern Europe have indicated that Rhodiola rosea ingestion may produce such positive effects as improved cognitive function and reduced mental fatigue. Other research from this region has illustrated enhanced endurance exercise performance in both humans and rats. Studies conducted in Western Europe and in North America have indicated that Rhodiola rosea may possess substantial antioxidant properties but have produced mixed results when attempting to demonstrate an ergogenic effect during exercise in humans.