Different psychophysiological responses to a high-intensity repetition session performed alone or in a group by elite middle-distance runners     

《European Journal of Sport Science》2013,13(8):1045-1052

Abstract

Internal training load refers to the degree of disturbance in psychophysiological homeostasis provoked by a training session and has been traditionally measured through session-RPE, which is the product of the session Rate of Perceived Exertion (RPE) and the duration. External training load refers to the actual physical work completed, and depends on session volume, intensity, frequency and density. Drafting, which is achieved by running closely behind another runner has been demonstrated to reduce the energy cost of running at a fixed speed and to improve performance. Therefore, it is hypothesised that psychophysiological responses might reflect different levels of internal load if training is performed individually or collectively. 16 elite middle-distance runners performed two high-intensity training sessions consisting of 4 repetitions of 500?m separated by 3?min of passive recovery. Sessions were performed individually and collectively. Times for each repetition, RPE, core affect (valence and felt arousal) and blood lactate concentrations [BLa] were measured after each repetition. Main time effect was significant and increased across repetitions for [BLa] and RPE (p?<?0.001), and decreased for valence (p?=?0.001). Main group effect was significant and values were higher when training individually for [BLa] (p?=?0.003) and RPE (p?=?0.001), and lower for valence (p?=?0.001). No differential responses were found between conditions in terms of repeat time or felt arousal. Findings demonstrate that elite middle-distance athletes running collectively display lower levels of internal training load compared to running alone, despite external training load being similar.  相似文献   

High-intensity cycle interval training improves cycling and running performance in triathletes     

《European Journal of Sport Science》2013,13(6):521-529

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Words On Play     

Bernard Suits 《体育哲学杂志》2013,40(1):117-131

In his article, ‘Recovering Humanity: Movement, Sport, and Nature’, Doug Anderson addresses the place of endurance sport, or more generally sport at large, as a potential catalyst for the good life. Anderson contrasts transcendental themes of Henry David Thoreau and Ralph Waldo Emerson with the pragmatic claims of William James and John Dewey, who focus on human possibility and growth. Our aim is to pursue the pragmatic line of thought championed by James and Dewey as a contrasting but not mutually exclusive motive to Anderson’s analysis. We contend that movement can provide humanizing possibilities even more pronounced for those subscribing to pragmatic themes (i.e., growth and the strenuous mood). We will use running and cycling to demonstrate how the strenuous mood enhances the possibility for this humanizing condition. Specifically, we argue that moving in a committed fashion allows us to deepen our relationship with the respective practice and thus opens the possibilities for ‘recovering our humanity’.  相似文献   

Increased dietary carbohydrate and endurance during single‐leg cycling using a limb with normal muscle glycogen concentration     

A.E. Hardman  C. Williams 《Journal of sports sciences》2013,31(2):127-138

The purpose of this study was to test the hypothesis that increased availability of blood‐borne glucose would improve endurance after carbohydrate loading. A single‐leg exercise model was employed, taking advantage of the fact that supercompensation of muscle glycogen occurs only in a previously exercised limb. Endurance time to exhaustion at 70% of maximal oxygen uptake (VO₂max) was determined for 11 males and three females who were then allocated to a control group or a high‐carbohydrate (CHO) group. For 3 days following Test 1 the control group maintained a prescribed normal diet whilst the CHO group increased the proportion of energy derived from carbohydrate (62.1 ± 4.3% cf. 43.9 ± 2.0%, P < 0.01). The endurance test was then repeated using the leg that was inactive during Test 1. Endurance time was increased on Test 2 (123.7 ± 43.2 min cf. 98.5 ± 21.9 min, P <0.05 one‐tailed test) for the CHO group but not for the control group (101.8 ± 21.7 min cf. 107.5 ± 9.1 min, NS). There was no indication of enhanced carbohydrate metabolism during Test 2 for the CHO group but mean heart rate was lower during Test 2 than during Test 1 (145 ± 14 beat min ^‐1 cf. 152 ± 12 beat min ^‐1, P<0.05). These results suggest that the prior consumption of a high‐carbohydrate diet improves endurance during high‐intensity cycling with a limb with normal muscle glycogen concentration.  相似文献   

BASES Position Statement on Guidelines for Resistance Exercise in Young People     

G Stratton  M Jones  KR Fox  K Tolfrey  J Harris  N Maffulli 《Journal of sports sciences》2013,31(4):383-390

Abstract

Despite the performance concerns of dehydration in other sports, there are currently no data on the effects of rapid weight-loss on the physical and cognitive performance of jockeys in a sport-specific context. In a randomised crossover design, eight Great Britain (GB) male licensed jockeys were assessed for chest strength, leg strength, simulated riding performance (assessed by maximum pushing frequency on a mechanical riding simulator during the final two furlongs of a simulated 2 mile race) and simple reaction time after performing 45 min of exercise, during which euhydration was maintained (Control trial) or induced 2% dehydration (Rapid Weight-Loss trial). Reductions in both chest (–13.8 ± 3.03% vs. 0.62 ± 1.04%) and leg strength (–4.8 ± 4.8% vs. –0.56 ± 2.5%) were greater in Rapid Weight-Loss compared with Control (P < 0.01 and P = 0.04, respectively). Similarly, reductions in simulated riding performance were also greater (P = 0.05) in Rapid Weight-Loss (–2.8 ± 4.0%) compared with Control (–0.07 ± 1.5%), whereas there were no significant changes (P = 0.14) in simple reaction time. We conclude that a 2% reduction in body mass, as achieved by 45 min of moderate-intensity exercise undertaken in a sweatsuit (a common method of inducing acute dehydration by jockeys), significantly impairs maximum pushing frequency during a simulated race. In addition, the observed reductions in strength may also increase the occupational hazards associated with race riding.  相似文献   

Insulin sensitivity derived from oral glucose tolerance testing in athletes: Disagreement between available indices     

Konstantinos Niakaris  Faidon Magkos  Nikos Geladas  Labros S Sidossis 《Journal of sports sciences》2013,31(10):1065-1073

The aims of the present study were to determine whether available “fasting” and oral glucose tolerance test-derived insulin sensitivity indices could effectively discriminate between individuals with higher than normal insulin sensitivity, and whether they would all provide similar information in clinical practice. Sprint runners (n = 8), endurance runners (n = 8) and sedentary controls (n = 7) received a 75-g oral glucose tolerance test. All participants were healthy lean males, aged 21?–?29 years. Besides glucose and insulin responses, a total of nine such indices were computed. Fasting as well as post-load glucose concentrations were similar in the three groups, while basal plasma insulin and the insulinaemic response to glucose were both higher in untrained individuals (at P?<?0.05 and P?<?0.02, respectively). There were no differences between endurance and sprint runners. The results for insulin sensitivity, however, were quite variable: three indices showed that both groups of athletes were more insulin-sensitive than controls; three indicated that this was the case for endurance runners only; one indicated that this was the case for sprint runners only; and two showed that sprint runners were more insulin-sensitive than either sedentary individuals or endurance runners (all differences were significant at P?<?0.05). Controlling for total body weight or lean mass did not effectively resolve this disagreement. Apparently, the various insulin sensitivity indices examined provided different quantitative and qualitative information, despite insulin action being greater in both groups of athletes relative to controls, as reflected by their similar glucose tolerance with lower insulin concentrations. We suggest, therefore, that the use and interpretation of such indices among physically active individuals be made with caution.  相似文献   

Demographic characteristics of elite Kenyan endurance runners     

Vincent O. Onywera  Robert A. Scott  Michael K. Boit 《Journal of sports sciences》2013,31(4):415-422

Abstract

Kenyan athletes have dominated international distance running in recent years. Explanations for their success include favourable physiological characteristics, which could include favourable genetic endowment, and advantageous environmental conditions. The aim of this study was to compare the demographic characteristics of elite Kenyan runners with those of the general Kenyan population. Questionnaires, administered to 404 elite Kenyan runners specializing in distances ranging from the 800 m to the marathon and 87 Kenyan controls, obtained information on place of birth, language, and distance and method of travel to school. Athletes were separated into two groups according to athletic success: those who competed in international competition and those who competed in national competition. The athletes differed from controls in regional distribution, language, and distance and method of travel to school; athletes also differed from each other with the exception of method of travel to school. Most national and international athletes came from the Rift Valley province (controls 20%, national athletes 65%, international athletes 81%), belonged to the Kalenjin ethnic group (controls 8%, national athletes 49%, international athletes 76%) and Nandi sub-tribe (controls 5%, national athletes 25%, international athletes 44%), and spoke languages of Nilotic origin (controls 21%, national athletes 60%, international athletes 79%). A higher proportion of all athletes ran to school each day (controls 22%, national athletes 73%, international athletes 81%) and covered greater distances. In conclusion, Kenyan runners are from a distinctive environmental background in terms of geographical distribution, ethnicity and travelled further to school, mostly by running. These findings highlight the importance of environmental and social factors in the success of Kenyan runners.  相似文献   

Moderate-domain pulmonary oxygen uptake kinetics and endurance running performance     

A. E. Kilding  E. M. Winter  M. Fysh 《Journal of sports sciences》2013,31(9):1013-1022

Abstract

The aims of this study were to determine if the primary time constant (τ) for oxygen uptake ([Vdot]O₂) at the onset of moderate-intensity treadmill exercise is related to endurance running performance, and to establish if τ could be considered a determinant of endurance running performance. Thirty-six endurance trained male runners performed a series of laboratory tests, on separate days, to determine maximal oxygen uptake ([Vdot]O_2max), the ventilatory threshold (V_T) and running economy. In addition, runners completed six transitions from walking (4 km · h^?1) to moderate-intensity running (80% V_T) for the determination of the [Vdot]O₂ primary time constant and mean response time. During all tests, pulmonary gas-exchange was measured breath-by-breath. Endurance running performance was determined using a treadmill 5-km time-trial, after which runners were considered as combined performers (n=36) and, using a ranking system, high performers (n=10) and low performers (n=10). Relationships between τ and endurance running performance were quantified using correlation coefficients (r). Stepwise multiple regression was used to determine the primary predictor variables of endurance running performance in combined performers. Moderate correlations were observed between τ, mean response time and endurance running performance, but only for the combined performers (r=?0.55, P=0.001 and r=?0.50, P=0.002, respectively). The regression model for predicting 5-km performance did not include τ or mean response time. The velocity at [Vdot]O_2max was strongly correlated to endurance running performance in all groups (r=0.72 – 0.84, P < 0.01) and contributed substantially to the prediction of performance. In conclusion, the results suggest that despite their role in determining the oxygen deficit and having a moderate relationship with endurance running performance, neither τ nor mean response time is a primary determinant of endurance running performance.  相似文献   

Effects of concurrent training on interleukin-6, tumour necrosis factor-alpha and C-reactive protein in middle-aged men     

Cleiton Augusto Libardi  Giovana Verginia Souza  Arthur Fernandes GÁspari  Claudinei Ferreira Dos Santos  Sabrina Toffoli Leite  Rodrigo Dias 《Journal of sports sciences》2013,31(14):1573-1581

Abstract

The purpose of this study was to evaluate the effects of moderate- to high-intensity resistance and concurrent training on inflammatory biomarkers and functional capacity in sedentary middle-aged healthy men. Participants were selected on a random basis for resistance training (n = 12), concurrent training (n = 11) and a control group (n = 13). They performed three weekly sessions for 16 weeks (resistance training: 10 exercises with 3 × 8–10 repetition maximum; concurrent training: 6 exercises with 3 × 8–10 repetition maximum, followed by 30 minutes of walking or running at 55–85% [Vdot]O_2peak). Maximal strength was tested in bench press and leg press. The peak oxygen uptake ([Vdot]O_2peak) was measured by an incremental exercise test. Tumour necrosis factor-α, interleukin-6 and C-reactive protein were determined. The upper- and lower-body maximal strength increase for both resistance (+42.52%; +20.9%, respectively) and concurrent training (+28.35%; +21.5%, respectively) groups (P = 0.0001).[Vdot]O_2peak increased in concurrent training when comparing pre- and post-training (P = 0.0001; +15.6%). No differences were found in tumour necrosis factor-α and interleukin-6 for both groups after the exercise. C-reactive protein increased in resistance training (P = 0.004). These findings demonstrated that 16 weeks of moderate- to high-intensity training could improve functional capacity, but did not decrease inflammatory biomarkers in middle-aged men.  相似文献   

The Reliability of Distance Run Tests for Children in Grades K—4     

Roberta E. Rikli  Clayre Petray  Ted A. Baumgartner 《Research quarterly for exercise and sport》2013,84(3):270-276

Abstract

The purpose of this study was to determine test–retest reliability for the 1-mile, 3/4-mile, and 1/2-mile distance run/walk tests for children in Grades K—4. Fifty-one intact physical education classes were randomly assigned to one of the three distance run conditions. A total of 1,229 (621 boys, 608 girls) complied the test–retests in the fall (October), with 1,050 of these students (543 boys, 507 girls) repeating the tests in the spring (May). Results indicated that the 1-mile run/walk distance, as recommended for young children in most national test batteries, has acceptable intraclass reliability (.83 < R < .90) for both boys and girls in Grades 3 and 4, has minimal (fall) to acceptable (spring) reliability for Grade 2 students (.70 < R < .83), but is not reliable for children in Grades K and 1 (.34 < R < .56). The 1/2 mile was the only distance meeting minimal reliability standards for boys and girls in Grades K and 1 (.73 < R < .82). Results also indicated that reliability estimates remained fairly stable across gender and age groups from the fall to spring testing periods, with the exception of the noticeably improved values for Grade 2 students on the 1-mile run/walk test. Criterion-referenced reliability (P, percent agreement) was also estimated relative to Physical Best and Fitnessgram run/walk standards. Reliability coefficients for all age group standards were acceptable to high (.70 < P < .95), except for Fitnessgram standards for 5-year-old girls on the 1-mile test for both fall and spring and for 6-year-old boys and girls on the 1-mile test administered in the spring.  相似文献