Exercise intensity and metabolic response in singles tennis

The aim of this study was to determine exercise intensity and metabolic response during singles tennis play. Techniques for assessment of exercise intensity were studied on-court and in the laboratory. The on-court study required eight State-level tennis players to complete a competitive singles tennis match. During the laboratory study, a separate group of seven male subjects performed an intermittent and a continuous treadmill run. During tennis play, heart rate (HR) and relative exercise intensity (72 +/- 1.9% VO2max; estimated from measurement of heart rate) remained constant (83.4 +/- 0.9% HRmax; mean +/- s(x)) after the second change of end. The peak value for estimated play intensity (1.25 +/- 0.11 steps x s(-1); from video analysis) occurred after the fourth change of end (P< 0.005). Plasma lactate concentration, measured at rest and at the change of ends, increased 175% from 2.13 +/- 0.32 mmol x l(-1) at rest to a peak 5.86 +/- 1.33 mmol x l(-1) after the sixth change of end (P < 0.001). A linear regression model, which included significant terms for %HRmax (P< 0.001), estimated play intensity (P < 0.001) and subject (P < 0.00), as well as a %HRmax subject interaction (P < 0.05), accounted for 82% of the variation in plasma lactate concentration. During intermittent laboratory treadmill running, % VO2peak estimated from heart rate was 17% higher than the value derived from the measured VO2 (79.7 +/- 2.2% and 69.0 +/- 2.5% VO2peak respectively; P< 0.001). The %VO2peak was estimated with reasonable accuracy during continuous treadmill running (5% error). We conclude that changes in exercise intensity based on measurements of heart rate and a time-motion analysis of court movement patterns explain the variation in lactate concentration observed during singles tennis, and that measuring heart rate during play, in association with preliminary fitness tests to estimate VO2, will overestimate the aerobic response.     

The locus of focus: the effect of switching from a preferred to a non-preferred focus of attention

Focusing strategies are known to play a significant role in motor performance, with individuals who use an internal focus on body movement typically showing poorer outcomes than those who focus on features of the external environment. Focus of attention and switching of one's focus are examined in the context of two different complex motor skills along with a factor not previously examined systematically, individual preference. In both experiments, participants were introduced to focusing strategies that might be employed when attempting a sensorimotor task. Explanations of both strategies were given to participants. Specifically, for an internal focus, participants were instructed to concentrate on their body movements, while for an external focus, they were instructed to focus on aspects in the environment. They were then asked which strategy they preferred. Participants then continued either with their preferred focus or were instructed to switch to their non-preferred focus. The advantage that the external focus typically enjoys turns out not to be a simple one and interacts with individual preference and with the "forced-opposite" manipulation. Our results support the growing consensus that encouraging individuals to adopt an internal focusing strategy is counterproductive in complex sensorimotor tasks. They also suggest that individual preferences play a role.     

Building friendship through a cross-cultural mentoring program

This paper examines the efficacy of a short-term mentoring program in building cross-cultural friendships between students at an Australian university. Using a quasi-experimental approach, our study found that the mentoring program (Local Aussie Mentoring Program—LAMP) increased cross-cultural interactions for mentees, but not for mentors. About 45% of both mentors and mentees wished to continue their relationship with mentoring partners after the completion of the mentoring requirements. Mentees spent significantly more time with cross-ethnic friends than did controls after the completion of LAMP. We examined whether multicultural aspects of personality, as measured by the Multicultural Personality Questionnaire (MPQ), would positively correlate with cross-cultural mentoring effectiveness and cross-cultural friendship interactions (the dependent variables). Multicultural personality aspects of mentors (as measured by the MPQ) had significant positive relationships with both mentee and mentor-rated mentoring measures. All mentor MPQ scales showed some significant but small and positive relationships, with mentor friendship items, particularly Open-mindedness, Cultural Empathy and Emotional Stability. We found a significant, positive relationship between mentee Cultural Empathy and Social Initiative with cross-cultural friendship. These results show some partial support for a positive relationship between MPQ scales and cross-ethnic friendships.     

Life goals and academic interests as predictors of extracurricular activities of secondary school sophomores

The life goals and interests of eighth-graders were examined in relation to their reported extracurricular activities in secondary school. In 1969, 204 females and 178 males, attending three feeder schools, completed the Vocational Sentence Completion Blank, a semiprojective measure of life goals, values, quests, aspirations hopes, preferences, and concerns. For the Milwaukee Academic Interest Inventory, which measures curricular interests, the complete test records of 183 females and 150 males were available. In 1971, all subjects reported about their participation in six secondary school activities. Approximately two-thirds of the 29 VSCB categories and all 7 MAII variables were predictive at a low level of association. The statistically significant relations between eighth-grade predictors and specific extracurricular activities in the first year of secondary school seemed reasonable. Implications for adolescent development were discussed.