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21.
Orienteering is a sport in which it is common for most participants to be aged over 40 years, but research into the demands of the sport has focused almost exclusively on elite participants aged 21-35 years. The aim of the present study was to examine the heart rate responses of older male orienteers. Thirty-nine competitive male orienteers were divided into three groups: group 1 (international competitive standard, n = 11, age 21-67 years), group 2 (national competitive standard, n = 15, age 24-66 years) and group 3 (club competitive standard, n = 13, age 23-60 years). Each participant had his heart rate monitored during two orienteering races of contrasting technical difficulty. The results were analysed using analysis of covariance, with age as a covariate, and Pearson product-moment correlation coefficients to determine whether age was related to the observed heart rate responses. The groups did not differ in their peak (175 +/- 12 beats x min(-1), P = 0.643) or mean (159 +/- 13 beats x min(-1), P = 0.171) heart rates during the races. There was a decline of 6 beats x min(-1) x decade(-1) (P = 0.001) for peak heart rate and 5 beats x min(-1) x decade(-1) (P < 0.001) for mean heart rate. Mean heart rates were 86 +/- 6% of the participants' maximal heart rates and were not associated with age. The orienteers in group 1 displayed a lower (P < 0.005) within-race standard deviation in heart rate (6 +/- 2 beats x min(-1)) than those in groups 2 and 3 (10 +/- 3 and 10 +/- 4 beats x min(-1), respectively). In conclusion, the mean heart rates indicated that all three groups of orienteers ran at a relative high intensity and the international competitive standard orienteers displayed a less variable heart rate, which may have been related to fewer instances of slowing down to relocate and being able to navigate while running at relatively high speeds.  相似文献   
22.
In this study, we assessed the performance of trained senior (n = 6) and veteran (n = 6) cyclists (mean age 28 years, s = 3 and 57 years, s = 4 respectively). Each competitor completed two cycling tests, a ramped peak aerobic test and an indoor 16.1-km time-trial. The tests were performed using a Kingcycle ergometer with the cyclists riding their own bicycle fitted with an SRM powermeter. Power output, heart rate, and gas exchange variables were recorded continuously and blood lactate concentration [HLa] was assessed 3 min after the peak ramped test and at 2.5-min intervals during the time-trial. Peak values for power output (RMP(max)), heart rate (HR(peak)), oxygen uptake (VO2(peak)), and ventilation (V(Epeak)) attained during the ramped test were higher in the senior group (P < 0.05), whereas [HLa](peak), RER(peak), V(E): VO2(peak), and economy(peak) were similar between groups (P > 0.05). Time-trial values (mean for duration of race) for power output (W(TT)), heart rate (HR(TT)), VO2 (VO(2TT)), and V(E) (V(ETT)) were higher in the seniors (P < 0.05), but [HLa](TT), RER(TT), V(ETT): VO2(TT), and economy(TT) were similar between the groups (P > 0.05). Time-trial exercise intensity, expressed as %RMP(max), %HR(peak), % VO2(peak), and % V(Epeak), was similar (P > 0.05) for seniors and veterans (W(TT): 81%, s = 2 vs. 78%, s = 8; HR(TT): 96%, s = 4 vs. 94%, s = 4; VO2(TT): 92%, s = 4 vs. 95%, s = 10; V(ETT): 89%, s = 8 vs. 85%, s = 8, respectively). Overall, seniors attained higher absolute values for power output, heart rate, VO2, and V(E) but not blood lactate concentration, respiratory exchange ratio (RER), V(E): VO2, and economy. Veterans did not accommodate age-related declines in time trial performance by maintaining higher relative exercise intensity.  相似文献   
23.
24.
ABSTRACT

Current evidence suggests that chronic inflammation contributes to the development of coronary artery disease (CAD). Interestingly, exercise may constitute a method of reducing inflammation in this patient population. As such, this systematic review and meta-analysis examined the evidence generated by randomised studies that investigated the effect of exercise on inflammatory biomarkers in CAD. Literature was sought from various sources. Outcomes were pooled in a random-effects model to calculate standardised mean differences (SMD) with 95% confidence intervals (CI). Twenty-five studies were reviewed; post-intervention C-reactive protein (SMD: ?0.55 (95% CI: ?0.93, ?0.16), P = 0.005), fibrinogen (SMD: ?0.52 (95% CI: ?0.74, ?0.29, P = <0.00001)), and von Willebrand factor (SMD: ?1.57 (95% CI: ?2.23, ?0.92), P = <0.00001) values were significantly lower in exercise groups compared to controls. In addition, qualitative analyses identified evidence that supports a beneficial effect of exercise on these acute-phase reactants. However, the impact of exercise on anti–inflammatory cytokines, adhesion molecules, and chemokines is equivocal, which may be attributed to a paucity of research. Nevertheless, the findings of this review suggest that exercise induces an anti–inflammatory effect in CAD patients. Although, the quality of evidence needs to be improved by further randomised studies with high methodological qualities and large sample sizes.  相似文献   
25.
Proposes for Asian customers a supplement to the conventional Western model of marketing by placing relationships at the centre and emphasising systems and attitudes.  相似文献   
26.
This paper compares the attitudes of Kenyan and Malawian rural parents to educating girls, using perceptions of gender-specific academic potential, educational aspirations and opinions on the gender appropriateness of primary school subjects and various careers. Suggestions are offered as to how these attitudes affect girls' educational attainment. The paper closes with a discussion of the ways that parents' attitudes affect girls' completion of primary school in Malawi and how the high wastage rate might be cut.  相似文献   
27.
Latent growth curve modeling provides a powerful and flexible tool for researchers to study individual differences in change as well as the correlates and predictors of change. Recent developments in estimation and hypothesis testing procedures are largely based on confirmatory structural equation approaches. In this article, an alternative exploratory approach is proposed for the analysis of growth and change using multidimensional scaling (MDS). When applied to growth data, it is a growth pattern recognition technique that partitions individual differences into initial level and growth pattern components. When applied to other longitudinal data, it can be used to study change patterns. A math achievement data set is used to illustrate the growth modeling method and a mood variable is used to illustrate change modeling. The strengths and limitations of the MDS growth profile analysis are discussed.  相似文献   
28.
Response times have often been used as ancillary information to improve parameter estimation. Under the dual processing theory, assuming reading comprehension requires an automatic process, a fast, correct response is an indicator of effective automatic processing. A skilled, automatic comprehender should be high in response accuracy and low in response times. Following this argument, several questions were addressed in this study. First, individuals with higher ability endorsed a correct response more quickly in the reading comprehension assessment, suggesting correct response times provide useful information in discriminating individuals of different abilities. Second, in terms of predicting an external criterion of reading proficiency, the increment of predictive validity of categorized correct response times was larger than the incremental validity of continuous response times based on both correct and incorrect response times. An index reflecting both accuracy and response time yielded higher incremental validity than indices reflecting response time only. Results support response time as manifesting a dimension of interest in its own right, over its inclusion as an ancillary dimension in a multidimensional model.  相似文献   
29.
W. Phillips Davison's Mass Communication and Conflict Resolution: The Role of the Information Media in the Advancement of International Understanding (New York: Praeger Special Studies, 1974—price not known, but about $12.00)

EBU—25 Years (Geneva: EBU, 1974—price not known)

Sydney W. Head and Lois Beck's The Bibliography of African Broadcasting: An Annotated Guide (Philadelphia: School of Communications and Theater of Temple University, 1974—$2.00, paper)

Rural Broadcasting in Dahomey (Rome: Food and Agricultural Organization [of the United Nations] released in this country by Unipub Inc., P.O. Box 433, New York, N.Y. 10016—$5.00 for filmstrip and accompanying illustrated booklet of text)

1974 Report to the President and the Congress (Washington: Communications Satellite Corporation, 950 L'Enfant Plaza, Washington D.C. 20024—free on request, along with earlier versions of the annual review)

Jacques Moussear (general editor) Les Communications de Masse: L'Univers des Mass Media (Paris: Hachette, 1972—about $12.55)  相似文献   
30.
ABSTRACT

The aim of this trial was to compare an eight-week individual movement quality versus traditional resistance training intervention on movement quality and physical performance. Forty-six trained adults were randomised to a movement quality-focused training (MQ) or a traditional resistance training (TRAD) group, and performed two individualised training sessions per week, for 8 weeks. Session-RPE (sRPE) was obtained from each session. Measures of movement quality (MovementSCREEN and Functional Movement Screen (FMS)) and physical performance were performed pre- and post-intervention. All measures improved significantly in both groups (3–14.5%, p = <0.005). The between-group difference in MovementSCREEN composite score was not statistically significant (0.3, 95% CI ?3.4, 4.1, p = 0.852). However, change in FMS composite was significantly greater in MQ (1.3, 95% CI 0.8, 1.8, p < 0.001). There were no significant between-group differences in physical performance (p = 0.060–0.960). The mean sRPE was significantly lower in MQ (5.25, SD 1.2) compared to TRAD (6.6 SD 1.0, p = <0.001). Thus, although movement quality scores were not distinctly greater in the MQ group, a movement quality specific intervention caused comparable improvements in physical performance compared to traditional resistance training but at lower perceived training intensity.  相似文献   
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