Search Results

You are looking at 1 - 10 of 801 items for :

Clear All
Restricted access

Sergi García, Selen Razon, Robert Hristovski, Natàlia Balagué and Gershon Tenenbaum

Drawing upon the nonlinear model of attention focus, the purpose of this study was to compare the intrinsic and intentional dynamics of task-related thoughts (TRT) in trained runners and nonrunners during an incremental maximal test. Fourteen trained runners and 14 nonrunners were assigned to 2 conditions: intrinsic (nonimposed thoughts) and intentional (imposed, task-unrelated thoughts; TUT). A significant effect of running velocity over TUT/TRT dynamics in both groups and conditions was observed (p < .001). Although, all participants received instructions to keep TUT for the entire duration of the test, an initially stable TUT phase was followed by a metastable phase (i.e., switches between TUT and TRT) an a final stable TRT phase nearing volitional exhaustion. The stable TRT phase lasted longer in runners group (p < .05) and included higher probabilities in pace monitoring thoughts subcategory (p < .05). The results revealed that trained runners seem to use TRT (i.e., pace monitoring) to maximize performance, and confirm the nonlinear model of attention focus during incremental maximal run in trained runners and nonrunners.

Restricted access

Dennis Passe, Mary Horn, John Stofan, Craig Horswill and Robert Murray

This study investigated the relationship between runners’ perceptions of fluid needs and drinking behavior under conditions of compensable heat stress (ambient temperature = 20.5 ± 0.7 °C, 68.9 °F; relative humidity = 76.6%). Eighteen experienced runners (15 men, 40.5 ± 2.5 y, and 3 women, 42 ± 2.3 y) were given ad libitum access to a sports drink (6% carbohydrate-electrolyte solution) at Miles 2, 4, 6, and 8. After the run (75.5 ± 8.0 min), subjects completed questionnaires that required them to estimate their individual fluid intake and sweat loss. Dehydration averaged 1.9% ± 0.8% of initial body weight (a mean sweat loss of 21.6 ± 5.1 mL·kg−1·h−1). Subjects replaced only 30.5% ± 18.1% of sweat loss and underestimated their sweat loss by 42.5% ± 36.6% (P ≤ 0.001). Subjects’ self-estimations of fluid intake (5.2 ± 3.2 mL·kg−1·h−1) were not significantly different from actual fluid intake (6.1 ± 3.4 mL·kg−1·h−1) and were significantly correlated (r = 0.63, P = 0.005). The data indicate that even under favorable conditions, experienced runners voluntarily dehydrate (P ≤ 0.001), possibly because they are unable to accurately estimate sweat loss and consequently cannot subjectively judge how much fluid to ingest to prevent dehydration. This conclusion suggests that runners should not depend on self-assessment to maintain adequate hydration, underscores the need for runners to enhance their ability to self-assess sweat losses, and suggests that a predetermined regimen of fluid ingestion might be necessary if they wish to maintain more optimal hydration.

Restricted access

Renée M. Parker, Michael J. Lambert and Gary M. Burlingame

The present study was conducted to determine if female distance runners who report engaging in pathological food behaviors display the psychological characteristics of clinically diagnosed female eating-disordered patients. Comparisons were made among 29 eating-disturbed college runners, 31 normal college runners, 19 clinically diagnosed eating-disordered patients, and 34 nonathletic, non-eating-disordered college students. Measures included a 3-day diet journal, questionnaires collecting both personal information and information on eating behaviors and sports participation, the Eating Disorder Inventory (EDI), the Setting Conditions for Anorexia Nervosa Scale (SCANS), and the Minnesota Multiphasic Personality Inventory (MMPI). Without reaching eating-disordered clinical levels, the eating-disturbed runners appeared on psychological inventories as being more concerned with food and dieting than were the comparison runners and non-eating-disordered nonathletes. Only the eating-disordered group presented with significant levels of psychopathology. Implications for the athletic community are discussed.

Restricted access

Fernando Naclerio, Eneko Larumbe-Zabala, Mar Larrosa, Aitor Centeno, Jonathan Esteve-Lanao and Diego Moreno-Pérez

composition and performance in well-trained male endurance runners. The primary outcomes measures were whole-body fat mass, whole-body lean mass, total trunk fat mass, trunk lean mass, visceral fat mass, total (right and left) upper and lower body limb lean and fat mass. Secondary outcomes measures included

Restricted access

Tzu-Chieh Liao, Joyce H. Keyak and Christopher M. Powers

, frontal, and transverse planes can contribute to altered patellofemoral joint stress. 12 Indeed, runners with PFP have been reported to exhibit greater degrees of hip internal rotation, hip adduction, and knee valgus compared with runners without PFP. 8 , 13 – 15 In the sagittal plane, the knee flexion

Restricted access

John H. Challis, Chloe Murdoch and Samantha L. Winter

The purpose of this study was to compare the heel pad mechanical properties of runners, who repetitively load the heel pad during training, with cyclists who do not load their heel pads during training. Ten competitive long distance runners and 10 competitive cyclists volunteered for this study. The thickness of the unloaded heel pad was measured using realtime B-mode ultrasonography. A heel pad indentation device was used to measure the mechanical properties of the heel pads. To evaluate the differences between the two groups, in heel pad properties, a repeat measures analysis of variance was used (p < .05). Heel pad thickness was not different between groups when normalized with respect to subject height. There was no significant difference between the groups in percentage energy loss during loading and unloading (runners: 61.4% ± 8.6; cyclists: 62.5% ± 4.6). Heel pad stiffness for the runners was statistically significantly less than that of the cyclists (p = .0018; runners: 17.1 N·mm−1 ± 3.0; cyclists: 20.4 N·mm−1 ± 4.0). These results indicate that the nature of the activity undertaken by individuals may influence their heel pad properties. This finding may be important when considering differences in heel pad properties between different populations.

Restricted access

Nicholas Tam, Ross Tucker, Jordan Santos-Concejero, Danielle Prins and Robert P. Lamberts

propulsion and agonist–antagonist coactivation, are also believed to influence running economy, though fewer studies have explored this relationship to date. 15 Interestingly, research participants involved in studying these relationships vary from novice runners to elite runners, 5 , 8 and it is well

Restricted access

Christian A. Clermont, Sean T. Osis, Angkoon Phinyomark and Reed Ferber

runners based on actual race performance is limited. Cavanagh et al 14 compared lower-limb angular kinematics between “elite” and “good” runners, and found significant differences in ankle plantarflexion angles in preparation for toe off. However, only sagittal plane motion was studied, and all

Restricted access

Katrina Taylor, Jeffrey Seegmiller and Chantal A. Vella

Purpose:

To determine whether a decremental protocol could elicit a higher maximal oxygen consumption (VO2max) than an incremental protocol in trained participants. A secondary aim was to examine whether cardiac-output (Q) and stroke-volume (SV) responses differed between decremental and incremental protocols in this sample.

Methods:

Nineteen runners/triathletes were randomized to either the decremental or incremental group. All participants completed an initial incremental VO2max test on a treadmill, followed by a verification phase. The incremental group completed 2 further incremental tests. The decremental group completed a second VO2max test using the decremental protocol, based on their verification phase. The decremental group then completed a final incremental test. During each test, VO2, ventilation, and heart rate were measured, and cardiac variables were estimated with thoracic bioimpedance. Repeated-measures analysis of variance was conducted with an alpha level set at .05.

Results:

There were no significant main effects for group (P = .37) or interaction (P = .10) over time (P = .45). VO2max was similar between the incremental (57.29 ± 8.94 mL · kg–1 · min–1) and decremental (60.82 ± 8.49 mL · kg–1 · min–1) groups over time. Furthermore, Q and SV were similar between the incremental (Q 22.72 ± 5.85 L/min, SV 119.64 ± 33.02 mL/beat) and decremental groups (Q 20.36 ± 4.59 L/min, SV 109.03 ± 24.27 mL/beat) across all 3 trials.

Conclusions:

The findings suggest that the decremental protocol does not elicit higher VO2max than an incremental protocol but may be used as an alternative protocol to measure VO2max in runners and triathletes.

Restricted access

Carl Foster, Jos J. de Koning, Christian Thiel, Bram Versteeg, Daniel A. Boullosa, Daniel Bok and John P. Porcari

The achievement of a world record (WR) is one of the most fundamental markers of excellence in athletic performance. However, as dramatic as the absolute level of performance is, it requires a runner to do something that they have never accomplished before; indeed, to do what no human has done