Evaluating a model of global psychophysical judgments—I: Behavioral properties of summations and productions

The research presented is a partial empirical evaluation of the second author's proposed psychophysical theory [Luce (2002). Psychological Review, 109, 520-532; Luce (2004). Psychological Review, 111, 446-454]. The theory deals with the global percept of subjective intensity, in which there is a psychophysical function Ψ that maps pairs of physical intensities onto the positive real numbers and represents, in an explicit mathematical way, subjective summation and a form of ratio production. A number of behavioral properties have been shown to follow from these specific representations, and in the presence of certain plausible background assumptions these properties are also sufficient for the representations. In four auditory experiments, key behavioral properties of summation over the two ears and a form of generalized ratio production are evaluated empirically. Considerable support is reported for particular forms of Ψ for summations and ratio productions separately. A second article, Steingrimsson and Luce (Journal of Mathematical Psychology, in press), explores the behavioral properties that link summations and productions.     

Measurement by subjective estimation: Testing for separable representations

Studying how individuals compare two given quantitative stimuli, say d₁ and d₂, is a fundamental problem. One very common way to address it is through ratio estimation, that is to ask individuals not to give values to d₁ and d₂, but rather to give their estimates of the ratio p=d₁/d₂. Several psychophysical theories (the best known being Stevens’ power-law) claim that this ratio cannot be known directly and that there are cognitive distortions on the apprehension of the different quantities. These theories result in the so-called separable representations [Luce, R. D. (2002). A psychophysical theory of intensity proportions, joint presentations, and matches. Psychological Review, 109, 520–532; Narens, L. (1996). A theory of ratio magnitude estimation. Journal of Mathematical Psychology, 40, 109–788], which include Stevens’ model as a special case. In this paper we propose a general statistical framework that allows for testing in a rigorous way whether the separable representation theory is grounded or not. We conclude in favor of it, but reject Stevens’ model. As a byproduct, we provide estimates of the psychophysical functions of interest.     

Psychological need satisfaction and thwarting: A test of Basic Psychological Needs Theory in physical activity contexts

ObjectivesTo test Basic Psychological Needs Theory (BPNT; Deci & Ryan, 2002) to determine if psychological need thwarting experienced when physically active contributes to the understanding of well-being and ill-being.Design/methodParticipants (N = 155, 67.70% female, M_age = 37.46 years; SD_age = 19.89 years) completed assessments of psychological need satisfaction and thwarting, subjective vitality and positive/negative affect during separate testing sessions separated by 6 months.ResultsScores from the modified version of the Psychological Need Thwarting Scale (PNTS-PA; Bartholomew, Ntoumanis, Ryan, & Thøgersen-Ntoumani, 2011) demonstrated discriminant evidence of validity, evidence of internal structure and minimal error variance. Changes in psychological need satisfaction positively predicted positive affect (R² = .16, p < .05), subjective vitality (R² = .13, p < .05) and negatively predicted negative affect (R² = .12, p < .05). Additional regression analyses revealed that changes in psychological need thwarting predicted negative affect (ΔR² = .11, p < .05), but not positive affect (ΔR² = .01, p > .05) or subjective vitality (ΔR² = .04, p > .05) beyond contributions made by psychological need satisfaction.ConclusionsOverall, these results extend the potential utility of the PNTS-PA as an instrument for use with BPNT beyond sport and support Deci and Ryan's (2002) contentions regarding the critical role of psychological need thwarting.     

A solution to a problem raised in Luce and Marley (2005)

Luce and Marley [2005. Ranked additive utility representations of gambles: Old and new axiomatizations. Journal of Risk and Uncertainty, 30, 21-62] examined various relations between mathematical forms for the utility of joint receipt ⊕ of gambles and for the utility of uncertain gambles. Their assumptions lead to a bisymmetry functional equation which, when the gambles are ranked, is defined on a restricted domain. Maksa [1999. Solution of generalized bisymmetry type equations without surjectivity. Aequationes Mathematicae, 57, 50-74] solved the general case and Kocsis [2007. A bisymmetry equation on restricted domain. Aequationes Mathematicae, 73, 280-284] presents the solution for the ranked case. The latter solution allows us to solve open problem 5 in Luce and Marley (2005) by showing that the assumptions of their Theorem 19 for an order-preserving ranked additive utility (RAU) representation U imply that U is a ranked weighted utility (RWU) representation that is additive over ⊕.     

Torgerson’s conjecture and Luce’s magnitude production representation imply an empirically false property

The prediction presented is based upon the empirically well sustained magnitude production representation that arose in both of Luce’s global psychophysical theories for subjective intensity of binary and unary continua coupled with Torgerson’s (1961) conjecture that respondents fail to distinguish subjective differences from subjective ratios. When applied to eqisections and fractionation the conjecture implies that the cognitive distortion function of the magnitude production representation is the identity function, which is firmly rejected by existing data.     

Predicting changes in planning behaviour and physical activity among adults

Though the effect of action planning upon behavioural enactment is becoming well-established, adherence to planning interventions are modest. Motivations specific to action planning may predict planning behaviour. The primary purpose of the present study was to determine if theory of planned behaviour constructs operationalized for planning could predict change in planning behaviour. The secondary purpose was to determine if planning behaviour predicted changes in physical activity. Participants (n = 337, M_age = 31 ± 5) were adults with intentions to be more active who completed measures of affective and instrumental attitudes towards planning, subjective norms towards planning, perceived behavioural control over planning, intentions to plan, self-reported planning behaviour, intentions to be active and self-reported physical activity at baseline (T1) and after four weeks (T2). Affective attitudes towards planning (β = 0.10, p < .05), instrumental attitudes towards planning (β = 0.22; p < .01) subjective norms over planning (β = 0.12, p < .01) and perceived behavioural control over planning (β = 0.53, p < .01) predicted intentions to plan (adj. R² = 0.66). Intentions to plan (β = 0.16, p < .05) and intentions to be active (β = −0.25, p < .05) predicted change in planning behaviour (R²_change = 0.03). Planning behaviour (β = 0.27, p < .05) predicted change in physical activity (R²_change = 0.07). Planning behaviour appears to have its own motivations distinct from those of physical activity. Future interventions should target planning behaviour along with its motivations and control beliefs to increase rates of planning. The theoretical underpinnings of the TPB are of value for understanding both planning behaviour and physical activity.     

Well-Being and Generalized Anxiety in Japanese Undergraduates: A Prospective Cohort Study

Psychological well-being is thought to protect against common mental health problems. This study investigated the buffering effects of psychological well-being on the relationships between cognitive vulnerabilities (fear of anxiety and negative beliefs about worry) and GAD symptoms among 297 Japanese undergraduates (female = 62%, age = 18.91 ± 1.61) in a two-wave prospective cohort study. Participants completed the Generalized Anxiety Disorder Questionnaire for DSM-IV, Center for Epidemiologic Studies Depression Scale, anxiety control subscale of Affective Control Scale, negative belief about worry subscale of Meta-Cognitions Questionnaire, and Nishida’s psychological well-being scale. A moderated regression analysis tested the buffering effect of psychological well-being sub-dimensions on the relationship between cognitive vulnerabilities and generalized anxiety symptoms. Fear of anxiety (β = 0.16, p < 0.01) and negative beliefs about worry (β = 0.16, p < 0.01) at baseline predicted generalized anxiety at follow-up, after controlling for baseline symptoms, and three interaction terms significantly predicted generalized anxiety symptoms. Purpose in life and autonomy buffered the negative relationship between cognitive vulnerabilities and generalized anxiety symptoms. Contrary to the hypothesized relationship, positive relationships with others at baseline facilitated a positive relationship between fear of anxiety and generalized anxiety symptoms. Those results suggested that enhanced Purpose in life and Autonomy dimension of Psychological well-being may be useful in preventing GAD, while the enhanced positive relationship with others dimension of Psychological well-being may facilitate generalized anxiety, as a function of fear of anxiety. In a primary prevention setting, it may be useful to consider the dimensions of Psychological well-being.     

Religion and Happiness Among Israeli Jews: Findings from the ISSP Religion III Survey

This study investigates religious predictors of happiness in a population-based sample of Israeli Jewish adults (N = 991). Using data collected in 2009–2010 as a part of the International Social Survey Programme’s Religion III Survey, analyses were conducted on a fully recursive structural model of the effects of synagogue attendance and several religious mediators on a single-item measure of happiness. Bivariately, every religious measure (synagogue attendance, prayer frequency, certainty of God beliefs, a four-item Supernatural Beliefs Scale, and subjective religiosity) is positively and significantly associated with happiness. In the structural model, 11 of 15 hypothesized paths are significant. Of these, only subjective religiosity exhibits a significant direct effect on happiness (β = 0.15, p < .01). The other four religious indicators, however, all exert indirect effects on happiness through subjective religiosity and combinations of each other. Total effects on happiness of both synagogue attendance (β = 0.10, p < .01) and the Supernatural Beliefs Scale (β = 0.12, p < .05) are statistically significant. Analyses adjust for effects of age and other sociodemographic covariates. Results build on a growing body of population-based findings supporting a salutary impact of Jewish religious observance on subjective well-being in Israel and the diaspora.     

Sex differences in the impact of state and trait fatigue on gait variability

Conditions requiring greater attention or cognitive control, such as fatigue, lead to changes in the motor performance of a task. Perceived fatigue refers to subjective feelings of fatigue, can be expressed as a state variable or trait characteristic and is influenced by demographic factors, such as sex. The purpose of this study was to determine how sex interacts with state and trait physical fatigue (PF) and mental fatigue (MF) to influence gait variability. METHODS: 123 healthy adults (77 female, 46 male), aged 18–36 years, completed the Mental and Physical State and Trait Energy and Fatigue Scale. Using a median split for each fatigue variable, participants were placed into “low” or “high” fatigue categories. Gait variability was defined as the asymmetry of lateral step variability (ALSV) and coefficient of variation (CV) of gait speed, stride length and double limb (DL) support during overground walking. RESULTS: Males with low state PF had greater ALSV than females with low state PF (p = 0.05, η²_p = 0.07) and males with high state PF (p = 0.007, η²_p = 0.15). Females with high trait MF had greater CV of gait speed than females with low trait mental fatigue (p = 0.02, η²_p = 0.08). Males with low trait MF had greater CV of gait speed (p = 0.01, η²_p = 0.10) and stride length (p = 0.002, η²_p = 0.17) than females with low trait MF. CV of DL support did not vary based on fatigue level or sex (p ≥ 0.11). CONCLUSIONS: There are sex-specific differences in the impact of state PF on asymmetry of lateral step variability and trait MF on the variability of gait speed and stride length.     

The Relationship Between Parent and Child Dysfunctional Beliefs About Sleep and Child Sleep

Cognitive theories emphasise the role of dysfunctional beliefs about sleep in the development and maintenance of sleep-related problems (SRPs). The present research examines how parents’ dysfunctional beliefs about children’s sleep and child dysfunctional beliefs about sleep are related to each other and to children’s subjective and objective sleep. Participants were 45 children aged 11–12 years and their parents. Self-report measures of dysfunctional beliefs about sleep and child sleep were completed by children, mothers and fathers. Objective measures of child sleep were taken using actigraphy. The results showed that child dysfunctional beliefs about sleep were correlated with father (r = 0.43, p < 0.05) and mother (r = 0.43, p < 0.05) reported child SRPs, and with Sleep Onset Latency (r = 0.34, p < 0.05). Maternal dysfunctional beliefs about child sleep were related to child SRPs as reported by mothers (r = 0.44, p < 0.05), and to child dysfunctional beliefs about sleep (r = 0.37, p < 0.05). Some initial evidence was found for a mediation pathway in which child dyfunctional beliefs mediate the relationship between parent dysfunctional beliefs and child sleep. The results support the cognitive model of SRPs and contribute to the literature by providing the first evidence of familial aggregation of dysfunctional beliefs about sleep.     

Influence of step-surface visual properties on confidence,anxiety, dynamic stability,and gaze behaviour in young and older adults

BackgroundStep-surface visual properties are often associated with stair falls. However, evidence for decorating stairs typically concerns the application of step-edge highlighters rather than the entire step-surface. Here we examine the influence of step-surface visual properties on stair descent safety, with a view to generating preliminary evidence for safe stair décor.MethodsFourteen young (YA: 23.1 ± 3.7 years), 13 higher (HAOA: 67 ± 3.5) and 14 lower (LAOA: 73.4 ± 5.7) ability older adults descended a seven-step staircase. Older adults were stratified based on physiological/cognitive function. Step-surface décor patterns assessed were: Black and white (Busy); fine grey (Plain); and striped multicolour (Striped); each implemented with/without black edge-highlighters (5.5 cm width) totalling six conditions. Participants descended three times per condition. Confidence was assessed prior to, and anxiety following, the first descent in each condition. 3D kinematics (Vicon) quantified descent speed, margin of stability, and foot clearances with respect to step-edges. Eye tracking (Pupil-labs) recorded gaze. Data from three phases of descent (entry, middle, exit) were analysed. Linear mixed-effects models assessed within-subject effects of décor (×3) and edge highlighters (×2), between-subject effects of age (×3), and interactions between terms (α = p < .05).ResultsDécor: Plain décor reduced anxiety in all ages and abilities (p = .032, effect size: g_av = 0.3), and increased foot clearances in YA and HAOA in the middle phase (p < .001, g_av = 0.53), thus improving safety. In contrast, LAOA exhibited no change in foot clearance with Plain décor. Patterned décor slowed descent (Busy: p < .001, g_av = 0.2), increased margins of stability (Busy: p < .001, g_av = 0.41; Striped: p < .001, gav = 0.25) and reduced steps looked ahead (Busy: p = .053, gav = 0.25; Striped: p = .039, gav = 0.28) in all ages and abilities. This reflects cautious descent, likely due to more challenging conditions for visually extracting information about the spatial characteristics of the steps useful to guide descent.Edge highlighters: Step-edge highlighters increased confidence (p < .001, g_av = 0.53) and reduced anxiety (p < .001, g_av = 0.45) in all ages and abilities and for all décor, whilst removing them slowed descent in HAOA (p = .01, g_av = 0.26) and LAOA (p = .003, g_av = 0.25). Step-edge highlighters also increased foot clearance in YA and HAOA (p = .003, g_av = 0.14), whilst LAOA older adults showed no adaptation. No change in foot clearances with décor or step-edge highlighters in LAOA suggests an inability to adapt to step-surface visual properties.ConclusionPatterned step surfaces can lead to more cautious and demanding stair negotiation from the perspective of visually extracting spatial information about the steps. In contrast, plain décor with step edge highlighters improves safety. We therefore suggest plain décor with edge highlighters is preferable for use on stairs.     

Distress Tolerance and Social Support in Adolescence: Predicting Risk for Internalizing and Externalizing Symptoms Following a Natural Disaster

The purpose of the multi-measure, multi-wave, longitudinal study was to examine the interactive relation between behavioral distress tolerance (DT) and perceived social support (PSS) in 352 tornado-exposed adolescents aged 12–17 years (M = 14.44; SD = 1.74). At baseline, adolescents completed a computer-based task for DT, and self-report measures of PSS, depressed mood, posttraumatic stress disorder (PTSD), substance use, and interpersonal conflict. Symptoms also were assessed 4 and 12 months after baseline. Findings showed that lower levels of DT together with lower levels of PSS conferred risk for elevated symptoms of prospective depression (t(262) = ?2.04, p = .04; r_{effect size} = 0.13) and PTSD (t(195) = ?2.08, p = .04; r_{effect size} = 0.15) following a tornado. However, only PSS was significant in substance use t(139) = 2.20, p = .03; r_{effect size=}0.18) and conflict (t(138) = ?4.05, p < .0001; r_{effect size=}0.33) in our sample. Implications regarding adolescent DT, the transdiagnostic nature of PSS, and the clinical applications of our findings in the aftermath of a natural disaster are discussed.     

Acute Stress,Depression, and Anxiety Symptoms Among English and Spanish Speaking Children with Recent Trauma Exposure

A growing literature suggests the clinical importance of acute stress disorder symptoms in youth following potentially traumatic events. A multisite sample of English and Spanish speaking children and adolescents (N = 479) between the ages of 8–17, along with their caregivers completed interviews and self-report questionnaires between 2 days and 1 month following the event. The results indicate that children with greater total acute stress symptoms reported greater depressive (r = .41, p < .01) and anxiety symptoms (r = .53, p < .01). Examining specific acute stress subscales, reexperiencing was correlated with anxiety (r = .47, p < .01) and arousal was correlated with depression (r = .50, p < .01) and anxiety (r = .55, p < .01). Age was inversely associated with total acute stress symptoms (r = ?.24, p < .01), reexperiencing (r = ?.17, p < .01), avoidance (r = ?.27, p < .01), and arousal (r = ?.19, p < .01) and gender was related to total anxiety symptoms (Spearman’s ρ = .17, p < .01). The current study supports the importance of screening acute stress symptoms and other mental health outcomes following a potentially traumatic event in children and adolescents. Early screening may enable clinicians to identify and acutely intervene to support children’s psychological and physical recovery.     

Sport bodies: An examination of positive body image,sport-confidence,and subjective sport performance in Jamaican athletes

Guided by the Sport-Confidence Model, this study examined the associations among a positive body image, sport-confidence, and sport performance evaluations. Using a cross-sectional design, a purposive sample of 314 Jamaican athletes (male = 70.7%; $M_{age}$ = 22.85; SD = 4.89) completed measures of body and functionality appreciation, sport-confidence, and subjective sport performance. Results from path analysis provided evidence for good model-data fit. Body (B = 9.03, p < .001) and functionality (B = 4.93, p = .036) appreciation exerted direct effects on sport-confidence. Sport-confidence exerted a direct effect on sport performance evaluations (B = 0.09, p < .001). Body (B = 0.79, CI_95% [0.44, 1.17]) and functionality (B = 0.43, CI_95% [0.05, 0.92]) appreciation exerted indirect effects on sport performance evaluations through sport-confidence. Results indicate that supporting the development of a positive body image in athletes may contribute to feelings of sport-confidence and positive performance outcomes.     

The effects of lemon taste on attention,perceived exertion,and affect during a stepping task

ObjectivesTo better understand the effects of taste cues on delaying the attention shift from an external focus (dissociative) towards an internal focus (associative) as exercise intensity increases.DesignA between subjects' experimental design with random assignment to three groups: taste (lemon-flavored mouth guards), placebo (unflavored mouth guards), or control group (no mouth guards) was used. Participants reported perceived exertion, affect (i.e., pleasantness and arousal), and attention allocation before, during, and after performing a weighted stepping task.ResultsPerforming the task resulted in a gradual increase of perceived exertion, F (1.87, 74.89) = 63.05, p < .05, η_p² = .61, along with a shift from dissociative to associative attention, F (2.17, 86.68) = 35.57, p < .05, η_p² = .47 across all conditions. Additionally, participants reported feeling less pleasant and more aroused after task completion in all conditions. The lemon-flavored mouth guard failed to affect attention, F (4.33, 86.68) = 1.41, p = .23, η_p² = .07, perceived exertion, F (3.74, 74.86) = .38, p = .81, η_p² = .02, pleasantness, F (2, 40) = .126, p = .88, η_p² = .01, and arousal, F (2, 40) = 2.40, p = .10, η_p² = .10, differently than the other two conditions.ConclusionsThe study was one of the first to examine the effects of taste during an exertive task. Despite the non-significant effects of using a lemon-taste mouth guard on various cognitive variables (perception of exertion, attention allocation, pleasantness, and arousal), more scientific effort is needed to explore the effects of other tastes (e.g., sweet, bitter) and delivery methods (e.g., sprays, drops).     

Resilience to Interpersonal Trauma and Decreased Risk for Psychopathology in an Epidemiologic Sample

Quantitative measures of psychological resilience related to discrete stressors, such as interpersonal (IP) trauma, are lacking. The current study examined whether a novel, quantitative measure of resilience was related to decreased risk for a broad range of lifetime DSM-IV axis I disorders in an epidemiologic sample. Resilience was defined as the residual resulting from the difference between the individual’s predicted and observed PTSD symptom count, based on their cumulative exposure to IP traumatic events. Participants were 6288 adults (59.5% women; M _age  = 46.9, SD = 14.5) from the National Epidemiologic Study on Alcohol and Related Conditions endorsing at least one lifetime IP traumatic event. Logistic regressions were conducted to examine the relationship between resilience and axis I diagnoses, covarying for age, sex, education level, social support, and recent stressful life events. Greater resilience scores were associated with decreased likelihood of major depression (OR = .64, p < .001), generalized anxiety disorder (OR = .65, p < .001), social anxiety disorder (OR = .74, p < .001), panic disorder (OR = .65, p <. 001), and alcohol dependence (OR = .85, p < .001). Discrepancy between expected and observed PTSD symptom severity based on IP trauma load may represent a useful, quantitative measure of resilience.     

Two years of physically active mathematics lessons enhance cognitive function and gross motor skills in primary school children

Physically active lessons have been shown to enhance academic achievement. However, the effects on cognitive function and gross motor skill development remain unknown. The present study examined how the incorporation of physical activity bouts within Mathematics lessons affects cognitive function and gross motor skill development across 2 years in primary school children. Eighty-two children (6.6 ± 0.3 y) were allocated to an intervention (n = 36; completing 8 h/wk of physically active lessons) or control (n = 46) group. A battery of cognitive function tests was completed, alongside the TGMD-3 to assess gross motor skills. Physically active Mathematics lessons led to greater improvements across all measures of cognition, when compared to the control group (digit span forwards, p < 0.001, d = 1.5; digit span backwards, p = 0.017, d = 1.0; free word recall: p < 0.001, d = 1.3; selective visual attention: p < 0.001, d = 0.3; verbal fluency: p < 0.001, d = 0.9; arithmetic: p < 0.001, d = 1.8). Furthermore, the intervention group demonstrated greater improvements in overall score on the TGMD-3 (p < 0.001, d = 1.7), as well as the locomotion (p < 0.001, d = 1.1) and object control (p < 0.001, d = 1.5) sub-scales. The physically active Mathematics lessons intervention appears to offer synergistic benefits in relation to cognitive and motor development, which are critical for optimal development in the early years.     

Effect of psychostimulant medications on static balance performance in adults with attention deficit hyperactivity disorder: Within-subjects repeated-measure study

ObjectiveThis study examined the effect of psychostimulant medications nPS) on balance and functional motor performance in adults with attention-deficit/hyperactivity disorder (ADHD).MethodsParticipants completed two sessions (off-medication and on-medication) in a within-subjects repeated-measure study design. There was a minimum of seven days between the two sessions. During both sessions, participants stood for 30 s per condition on a force platform. The conditions were: feet-apart with 1) eyes-open and 2) eyes-closed; feet-together with 3) eyes-open and 4) eyes-closed. Participants performed three trials of timed up and go (TUG) and lateral step-up test (LSUT) during both sessions. Outcome measures were sway area (SA [cm²]), average sway velocity (SV [cm/s]), TUG average time (s), and average number of LSUT repetitions. Data were analyzed using multivariate repeated measures analysis of variance and paired t-tests for examining PS effects on balance (SA and SV) and functional motor performance (TUG and LSUT), respectively.ResultsThe sample included 45 adults (35 females; mean age = 28.4 ± 6.3 years). The repeated-measures MANOVA indicated that PS was associated with better SA [F(1,44) = 9.6; p = 0.003;η_p² = 0.18] but not with SV [F(1,44) = 1.0; p = 0.319;η_p² = 0.02]. PS was associated with significantly better SA with decreasing base-of-support [F(1,44) = 9.9; p = 0.003;η_p² = 0.18]. Additionally, PS use was associated with better TUG [t(1,44) = 2.65; p = 0.014;Cohen's d = 0.39] but not LSUT performances [t(1,44) = −0.68; p = 0.499;Cohen's d = −0.10].ConclusionsPS was associated with better SA and TUG in adults with ADHD. Further studies are needed to investigate the effects of PS on balance performance using rigorous designs in this population.ImpactHealthcare providers should screen for PS status and balance when treating adults with ADHD to enhance safe motor performance.     

Fatigue-induced dissociation between rate of force development and maximal force across repeated rapid contractions

We examined whether the presence of fatigue induced by prolonged running influenced the time courses of force generating capacities throughout a series of intermittent rapid contractions. Thirteen male amateur runners performed a set of 15 intermittent isometric rapid contractions of the knee extensor muscles, (3 s/5 s on/off) the day before (PRE) and immediately after (POST) a half marathon. The maximal voluntary contraction force, rate of force development (RFD_peak), and their ratio (relative RFD_peak) were calculated. At POST, considering the first (out of 15) repetition, the maximal force and RFD_peak decreased (p < 0.0001) at the same extent (by 22 ± 6% and 24 ± 22%, respectively), resulting in unchanged relative RFD_peak (p = 0.6). Conversely, the decline of RFD_peak throughout the repetitions was more pronounced at POST (p = 0.02), thus the decline of relative RFD_peak was more pronounced (p = 0.007) at POST (−25 ± 13%) than at PRE (−3 ± 13%). The main finding of this study was that the fatigue induced by a half-marathon caused a more pronounced impairment of rapid compared to maximal force in the subsequent intermittent protocol. Thus, the fatigue-induced impairment in rapid muscle contractions may have a greater effect on repeated, rather than on single, attempts of maximal force production.