A comparison of methods for estimating oxygen uptake during intermittent exercise

Sixteen female games players completed 15 min of intermittent exercise on a treadmill. The speed and incline of the treadmill were varied to elicit a similar heart rate response to that found during women's hockey match‐play. The mean heart rate response was 169 ± 8 beats min^‐1 and the mean work:rest ratio was 1:1.7. Oxygen uptake was estimated by applying the oxygen cost determined from an individual's heart rate‐oxygen uptake regression equation to the average heart rate each 5 s during the intermittent exercise. A second esimation of oxygen uptake was made from a time‐motion analysis by assigning a specific oxygen cost to each discrete movement during the intermittent exercise protocol. The true oxygen cost was calculated from the analysis of the expired gas. The heart rate analysis overestimated the true cost by a mean of 4.3 ± 5.3% (0.09 ± 0.11 1 min^‐1), and the time‐motion analysis underestimated the true value by a mean of 15.7 ± 6.3% (0.34 ± 0.15 1 min^‐1). There was a significant difference (P < 0.01) between the true value and both the estimates. It was concluded that heart rate analysis gives a much better indication of oxygen uptake during intermittent activity than time‐motion analysis.     

代谢组学运动选材与传统生化选材方法的比较

通过与传统生化选材方法进行对比,探索代谢组学这一新兴的系统生物学方法用于运动选材的可行性与优越性.将雄性SD大鼠24只,在幼年时(4周龄)即收集其尿样和血样,尿样用于核磁共振(NMR)代谢组学分析,血样用于测试血红蛋白(Hb)和血清睾酮(ST);然后开始渐增负荷游泳训练直至成年(14周龄),训练结束后进行负重耐力游泳能力测试,记录每只大鼠游泳至力竭的时间,并根据力竭时间长短进行排名,分为前3名组与4～24名组、前12名组与后12名组共4组;测试完成后,休息2d,断头处死,取右后肢腓肠肌测试琥珀酸脱氢酶(SDH)和乳酸脱氢酶(LDH).结果显示:无论是前3名组与4～24名组之间,还是前12名组与后12名组之间,Hb、ST、SDH和LDH指标均较为接近,并且相互交错,组间没有显著性差异;而大鼠的代谢特征图谱有明显的差异,不同组样本被明确地分开了,而同组的样本则出现了聚集.结果表明:大鼠幼年时的代谢特征图谱能一定程度反映它们成年后游泳能力的差异,相对于利用一个或者少数几个指标进行运动选材的传统生化方法,代谢组学这一系统生物学方法具独特的优势.     

A comparison of two criterion-referenced standard setting procedures for sports skills testing.

The application of criterion-referenced (CR) standard setting procedures in physical education has been limited to the examinee-centered model known as criterion groups. Alternative examinee-centered approaches are available but have not been applied in sport skills testing. The purpose of this study was to compare two examinee-centered models for setting performance standards for a sport skills test battery. CR performance standards were determined for the tennis skills test battery published in Tennis skills test manual (Hensley, 1989) using the borderline group (BG) (Livingston & Zieky, 1982) and criterion groups (CG) (Berk, 1976) models. The comparison of these two methods demonstrated that the CG method consistently produced performance standards that were lower than the BG method. In one instance the BG method produced a standard that was clearly unreasonable. Estimates of CR reliability for the CG standards (.76 less than or equal to P less than or equal to .93; .52 less than or equal to Kq less than or equal to .86) were higher than BG estimates (.55 less than or equal to P less than or equal to .84; .11 less than or equal to Kq less than or equal to .68). Although each method has strengths, neither is without problems. Results from this study suggest these two methods might be combined to minimize the problems associated with each. This combined method should produce standards with improved accuracy, validity, and reliability.     

Validation of a one-day self-report questionnaire for physical activity assessment in healthy adults

Abstract

A self-report physical activity scale (PAS) has previously been developed to document physical activity (MET-hours) undertaken by adults during an average weekday. The current study aimed to validate the PAS over 24 hours via pedometer determinations of physical activity in healthy, active adults, and to determine possible influences of gender and body mass status on this relationship. One-hundred and seven healthy university students (age 18–41 years) wore a pedometer (Yamax DigiWalker SW-700) during the waking hours of an average weekday followed by successful completion of the PAS. Relationships between the PAS and pedometer measures (steps taken and energy expenditure) were examined by Pearson's correlation coefficients. Significant (P<0.05) gender and body mass status differences were examined by two-way analysis of variance with Tukey post-hoc tests. Participants reported 48.0±10.4 MET-hours of activity, completed 11,506±4195 steps, and expended 499±227 kcal during an average weekday. Physical activity measures, except energy expenditure, were similar across groups by gender and body mass status. The total number of MET-hours was significantly associated with pedometer steps taken (r=0.375–0.568, P<0.01), and this relationship varied by gender and to a lesser extent by body mass status. The results of the current study show that the self-reported physical activity of healthy active adults was in line with the popular recommended dose of daily physical activity (10,000 steps per day) and was not influenced by gender or body mass status. Furthermore, over an average weekday, the PAS provided a simple, quick, and valid method to document physical activity undertaken by young healthy active adults that is comparable to pedometer readings.     

A comparison of two methods for the calculation of accumulated oxygen deficit

The aim of this study was to compare accumulated oxygen deficit data derived using two different exercise protocols with the aim of producing a less time-consuming test specifically for use with athletes. Six road and four track male endurance cyclists performed two series of cycle ergometer tests. The first series involved five 10 min sub-maximal cycle exercise bouts, a VO2peak test and a 115% VO2peak test. Data from these tests were used to estimate the accumulated oxygen deficit according to the calculations of Medb? et al. (1988). In the second series of tests, participants performed a 15 min incremental cycle ergometer test followed, 2 min later, by a 2 min variable resistance test in which they completed as much work as possible while pedalling at a constant rate. Analysis revealed that the accumulated oxygen deficit calculated from the first series of tests was higher (P < 0.02) than that calculated from the second series: 52.3 +/- 11.7 and 43.9 +/- 6.4 ml x kg(-1), respectively (mean +/- s). Other significant differences between the two protocols were observed for VO2peak, total work and maximal heart rate; all were higher during the modified protocol (P < 0.01 and P < 0.02, respectively). Oxygen kinetics were also significantly faster during the modified 2 min maximal test. We conclude that the difference in accumulated oxygen deficit between protocols was probably due to a reduced oxygen uptake, possibly caused by a slower oxygen on-response during the 115% VO2peak test in the first series, and VO2-power output regression differences caused by an elevated VO2 during the early stages of the second series.     

A comparison of reliability estimation using trials-to-criterion and sequential probability ratio testing

The purpose of this study was to compare estimates of test reliability obtained from two sequential testing plans--trials-to-criterion (TTC) and sequential probability ratio (SPR) testing--when reliability is defined as the consistency of classification. Data from a golf chip test given to 110 beginning golf students (n = 80 males; n = 30 females) at the University of Wisconsin were used for analysis. Test specifications for the SPR test were alpha = beta = .05, theta 0 = .70, and theta 1 = .50. Two mastery levels for the TTC test were examined, .70 and .60, with success criteria ranging from R = 6 to R = 12. For each sequential testing plan, both P and kappa were calculated to estimate reliability. Results for the total group and for gender indicated that reliability was higher with the SPR test when the mastery level was .70, while reliability was similar under both plans at a mastery level of .60. Median test lengths for the group were 21 for the SPR test and an average of 12 across all R values for the TTC test. Misclassification error rates for the TTC test, however, were substantially higher than under the SPR test, particularly for false nonmaster errors. These data suggest that SPR testing would be the preferred approach when misclassification errors are of primary importance, such as to determine minimal competency for certification. However, TTC testing is a viable alternative for classroom tests because of ease of administration and shorter test length.     

Sit-to-stand performance of older adults following strength training

A group of healthy older adults completed an 8-week resistance-training program. For 38 participants (14 men, 24 women; ages 60-90 years; M mass = 73.2 kg, SD = 12.3; M height = 1.65 m, SD = 0.08), pre- and postprogram sit-to-stand performance was analyzed (60 Hz video) focusing on center of mass kinematics surrounding transition. Significant changes were attributed to improved strength. Peak forward, downward, and upward velocities increased (16, 59, and 26%, respectively), and relative transition time was delayed 27%. These behaviors were more similar to those of healthy younger adults. Results also indicated strategy changes. Participants exploited their improved strength, forming a distinctive movement pattern emphasizing stability followed by a brisk rise. These adaptations represent meaningfully improved function in an important daily living activity.     

Construct validation of physical activity surveys in culturally diverse older adults: a comparison of four commonly used questionnaires

The purpose of this study was to establish validity evidence of four physical activity (PA) questionnaires in culturally diverse older adults by comparing self-report PA with performance-based physical function. Participants were 54 older adults who completed the Continuous Scale Physical Functional Performance 10-item Test (CS-PFP10), Physical Activity Scale for the Elderly (PASE), HAMPS Physical Activity Questionnaire for Older Adults, Yale Physical Activity Survey (YPAS), and modified Baecke questionnaire. The total PASE score, three outcome scores for the CHAMPS, and three summary indices for the YPAS were significantly correlated with total CS-PFP10 score. The modified Baecke exhibited no correlations with CS-PFP10 scores. The PASE, CHAMPS, and YPAS appear to be the most valid PA self-report questionnaires for culturally diverse older adults.     

Psychosocial wellbeing in active older adults: A systematic review of qualitative literature

Physical activity and wellbeing in older adults is a global priority in combating negative economic consequences associated with population aging. Quantitative research using a medicalized model clearly associates physical activity with physiological health benefits. However, it is argued that a review of qualitative literature exploring individual experiences of active older adults can provide important insights into physical activity, aging, and wellbeing – specifically, how discourses of ageing and self-identity may interact with physical activity levels. A literature search on electronic databases PsycARTICLES, PsycINFO, SPORTDiscus, and ProQuest was used to identify qualitative studies of older adults who exercise or engage in competitive sport. Findings reveal that both groups tend to resist dominant negative stereotypes of ageing and view physical activity as central to self- identity. Yet approaches to ageing varied with the competitive sport group adopting a more negative view of the ageing process. Whilst results suggest that different levels of physical activity may impact on the psychosocial wellbeing of older adults, inconsistent definitions of exercise and competitive sport make it impossible to group these differences according to specific physical activity levels. More precise definitions of physical activity constructs in future research may provide a better understanding of these differences.     

Typologies of Greek inactive older adults based on reasons for abstaining from exercise and conditions for change

The main purpose of this study was to examine typologies of non-exercisers based on reasons for physical inactivity and conditions reported to be necessary to change exercise behaviour. These typologies were then compared on psychological variables of interest and exercise history. Questionnaires were distributed to Greek older adults aged 60 and above who were recruited from social clubs and city cafés. Only individuals engaging in no regular exercise were recruited (n = 188). The results of hierarchical and k-means cluster analyses revealed two clusters for males ("approachable" and "unconvinced") and three for females ("unconcerned", "approachable", and "unconvinced"). The clusters differed significantly on psychological variables not used in the cluster solution. Exercise history distinguished between clusters only among males. The results reveal that physically inactive older adults are not a homogeneous group of individuals. Implementers of physical activity interventions should probably use a range of strategies that take into consideration that some sedentary older adults are more amenable to consider taking up exercise than others.     

A comparison of lactate indices during ramp exercise using modelling techniques and conventional methods

The aim of this study was to compare the lactate indices provided by single- and double-breakpoint models with lactate thresholds obtained with conventional methods. Arterial samples for the determination of lactate concentrations were drawn from eight participants at rest and every minute during a ramp test (15 W x min(-1)) on a cycle ergometer. Lactate thresholds were determined from a blood lactate concentration equal to 4 mM (LT(4)), from an increase of 1 mM above the resting level (Delta1 mM), and from indirect methods using ventilatory parameters. Other indices were computed from the modelling of the lactate curve using an exponential function (LSI), a polynomial function (Dmax), a semi-log model (SLog), a parabola plus delay model (Mod P), and a two-breakpoint model (Mod M). Mod P and Mod M showed poor agreement with the other methods. LT(4), Dmax, LSI, and respiratory exchange ratio equal to 1 were correlated with each other (0.81 相似文献   

Tai Ji Quan,the brain,and cognition in older adults

The relationship between physical activity (PA) and cognition has received much attention recently. While evidence of improved cognition following PA has consistently been observed, the majority of studies have spotlighted aerobic exercise and the effects of other modes of PA, such as Tai Ji Quan, on cognition have received limited attention. This article provides a brief review of the literature concerning the influence of Tai Ji Quan on cognition in older adults, including those with intact cognition and those with cognitive impairment. In addition, this review proposes potential mechanisms (cardiovascular fitness, motor fitness, movement coordination, social interaction, and meditation statuses as well brain structure and function) evaluated from a neuroimaging perspective that may explain the Tai Ji Quan–cognition relationship. Finally, we present suggestions for future research. In conclusion, Tai Ji Quan, with its multi-faceted characteristics, shows promise as a mode of PA for enhancing cognition, as well as brain health, in older adults. Based on the findings in this review, further exploration of the effects of Tai Ji Quan on cognition in older adults is warranted.     

A comparison of methods to determine maximal accumulated oxygen deficit in running

The aim of this study was to compare maximal accumulated oxygen deficit (hereafter O2 deficit) estimated from the methods of Whipp et al. (1986), Medbo et al. (1988), and Hill et al. (1998) to determine whether they agree sufficiently to be used interchangeably. Nineteen moderately to highly trained endurance runners first performed an incremental test to exhaustion for the determination of maximal oxygen uptake ([Vdot]O(2max)) and peak treadmill speed, followed by six randomly ordered constant-speed tests at 95, 100, 105, 110, 110, and 120% of peak treadmill speed. All tests were separated by at least 72 h and were performed within 4 weeks. The method of Whipp produced an O(2) deficit estimate that was lower than that derived from the method of Hill or Medbo (bias +/- 95% limits of agreement: -29.6 +/- 36.6 and -26.1 +/- 32.8 ml . kg(-1), respectively; P < 0.001). The O2 deficit did not differ between the methods of Hill and Medbo (bias +/- 95% limits of agreement: 3.5 +/- 41.6 ml . kg(-1); n.s.). However, poor correlations (0.21 < r < 0.33; n.s.) together with wide limits of agreement between O2 deficit estimates (70 - 80% of the mean response) clearly question using these methods interchangeably.     

田径娱乐化教学方法与传统教学方法效果比较

教学方法是实现教学目标的关键环节。通过实验对比的方法,实验前、后运用心境量表(BFS)研究工具和运动能力测试手段,研究田径娱乐化教学方法与传统教学方法对中学生身心健康的影响。实验结果表明,田径娱乐化教学方法优于传统技术教学方法,能更有效地改善中学生的心境状态,提高运动参与意识、协作精神和运动能力。