responders and nonresponders. Such an approach would increase our understanding of the potential effects of caffeine on human exercise physiology and performance. It is, however, difficult to reveal whether someone is a high or low responder to caffeine. To our knowledge, only 1 study 11 proposed a method
Andreas Apostolidis, Vassilis Mougios, Ilias Smilios, Johanna Rodosthenous and Marios Hadjicharalambous
Liam P. Kilduff, Yannis P. Pitsiladis, Louise Tasker, Jeff Attwood, Paul Hyslop, Andrew Dailly, Ian Dickson and Stan Grant
This study examined the effects of Cr supplementation on muscle strength in conjunction with resistance training in nonresistance-trained males utilizing strategies previously reported in the literature to help optimize muscle Cr uptake. Nineteen nonresistance-trained males underwent 4 weeks of resistance training (3 days · week−1) while assigned to Cr (20 g · d−1 Cr + 140 g · d−1 glucose) for 7 days (loading), followed by 5 g · d−1 Cr + 35 g · d−1 glucose for 21 days (maintenance; n = 9) or placebo (160 g · d−1 glucose [loading] followed by 40 g · d−1 [maintenance; n = 10]). In subjects classified as “responders” to Cr on the basis of body mass changes (n = 7), the magnitude of change in 180∞ · s−1 isokinetic (p = .029) and isometric (p = .036) force was greater compared to the placebo group. A positive correlation was found between changes in body mass and 180º · s−1 isokinetic (loading: r = 0.68, p = .04; maintenance: r = 0.70, p = .037) and isometric (loading: r = 0.82, p < .01) force. Estimated Cr uptake was also positively correlated with changes in 60º · s−1 (r = 0.90, p < .01) and 180º · s−1 (r = 0.68, p = .043) isokinetic force, and isometric force (r = 0.71, p = .033). These results indicate that Cr supplementation can increase muscle strength (allied with 4 weeks of strength training) but only in subjects whose estimated Cr uptake and body mass are significantly increased; the greater the Cr uptake and associated body mass changes, the greater the performance gains.
Benjamin J.I. Schellenberg, Jérémie Verner-Filion and Patrick Gaudreau
Passionate sports fans often support the same team over the course of many seasons or even their entire lives. Accordingly, fans almost always experience important team successes, such as championship victories, as extremely positive events. But fans can differ in how they respond to team
James G. Hollandsworth Jr and Gary E. Jones
This study was designed to investigate runners' perceptions of arousal and awareness of physiological responding before and after a 20-kilometer (12.4- mile) race. Participants (N = 98) completed pre- and postquestionnaires that included measures of awareness of physiological responding and self-defined states of activation and arousal. In order to identify those variables related to performance, the finishers were divided into three groups: fast, moderate, and slow. A discriminant analysis revealed that miles run in training each week, resting pulse rate, and weight were the best predictors of group membership. Of the several psychological variables, only prerace tension discriminated between the groups, with the faster runners reporting themselves as more fearful and “clutched-up” before the race. In terms of pre-post physiological and psychological effects, it was found that running 20 kilometers resulted in a significant, increased awareness of physiological responding, increased feelings of being tired and relaxed, and decreased feelings of tension and energy. These findings are discussed in terms of their implications for future research.
Four studies were conducted to assess the psychometric properties and the theoretical basis of a version of the Inventory of Desirable Responding in Relationships, which was originally developed and validated for the assessment of romantic relationships, in a different relational context (i.e., coach-athlete relationships). The first study aimed to address the content validity of the modified inventory, the Inventory of Desirable Responding in Coach-Athlete Relationship (IDR-CART) scale. The second study employed factor analytic techniques to examine its psychometric properties. Results confirmed the two-factor structure of the inventory: self-deception (CART-SD) and impression management (CART-IM). In the third study, data were collected under public and anonymous conditions. Results revealed, however, that neither condition supported the factor structure, thereby casting doubt on theoretical assumptions. The fourth study demonstrated that CART-SD is associated with indices of relationship quality, providing evidence of convergent validity. Limitations and future research directions are discussed.
Alison C. Jozsi, Esther E. Dupont-Versteegden, Jane M. Taylor-Jones, William J. Evans, Todd A. Trappe, Wayne W. Campbell and Charlotte A. Peterson
Studies have been performed in humans to identify changes in gene expression that may account for the relatively weak and variable response of aged muscle to resistance exercise. The gene expression profile of skeletal muscle from elderly (62–75 years old) compared to younger (20–30 years old) men demonstrated elevated expression of genes typical of a stress or damage response. The expression of the majority of these genes was unaffected by a single bout of high-intensity resistance exercise in elderly subjects but was altered acutely by exercise in younger subjects so as to approach the pre-exercise levels observed in older subjects. The inability of muscle from elderly subjects to respond to resistance exercise was also apparent in the expression of inflammatory response genes, which increased within 24 hours of the exercise bout only in younger subjects. Other genes with potentially important roles in the adaptation of muscle to exercise, showed a similar or even more robust response in older compared to younger subjects. Taken together, these results may help to explain the variable hypertrophic response of muscle from older individuals to resistance training.
Nick Dobbin, Jamie Highton, Samantha L. Moss and Craig Twist
Purpose: To determine the utility of running-only and rugby-specific, in-season sprint interval interventions in professional rugby league players. Methods: Thirty-one professional academy rugby players were assigned to a rugby-specific (SITr/s, n = 16) or running-only (SITr, n = 15) sprint interval training group. Measures of speed, power, change of direction ability, prone Yo-Yo Intermittent Recovery Test (Yo-Yo IR1) performance, and heart rate recovery were taken before and after the 2-week intervention as were submaximal responses to the prone Yo-Yo IR1. Internal, external, and perceptual responses were collected during SITr/s and SITr, with well-being and neuromuscular function assessed before each session. Results: Despite contrasting (possible to most likely) internal, external, and perceptual responses to the SIT interventions, possible to most likely within-group improvements in physical characteristics, heart rate recovery, and submaximal responses to the prone Yo-Yo IR1 were observed after both interventions. Between-group analysis favored the SITr/s intervention (trivial to moderate) for changes in 10-m sprint time, countermovement jump, change of direction, and medicine ball throw as well as submaximal (280–440 m) high metabolic power, PlayerLoad™, and acceleration distance during the prone Yo-Yo IR1. Overall changes in well-being or neuromuscular function were unclear. Conclusions: Two weeks of SITr/s and SITr were effective for improving physical characteristics, heart rate recovery, and submaximal responses to the prone Yo-Yo IR1, with no clear change in well-being and neuromuscular function. Between-group analysis favored the SITr/s group, suggesting that the inclusion of sport-specific actions should be considered for in-season conditioning of rugby league players.
Kristiann C. Heesch, Jannique van Uffelen and Wendy J. Brown
The aim of this study was to examine older adults’ understanding and interpretation of a validated questionnaire for physical activity surveillance, the Active Australia Survey (AAS). To address this aim, cognitive interviewing techniques were used during face-to-face semistructured interviews with 44 adults age 65–89 years. Qualitative data analysis revealed that participants were confused with questionnaire phrasing, misunderstood the scope of activities to include in answers, and misunderstood the time frame of activities to report. They also struggled to accurately estimate the frequency and duration of their activities. Our findings suggest that AAS questions may be interpreted differently by older adults than intended by survey developers. Findings also suggest that older adults use a range of methods for calculating PA frequency and duration. The issues revealed in this study may be useful for adapting AAS for use in older community-dwelling adults.
Michael Skipper and Leslie A. Meehan
Active transportation refers to modes of travel that incorporate physical activity as part of the trip. Examples include walking and bicycling, as well as transit, since walking or bicycling is typically required for transit station access and egress. The Nashville Area Metropolitan Planning Organization has recently restructured its regional transportation policies and programming priorities as part of the development of the 2035 Regional Transportation Plan to enable more active transportation by encouraging the implementation of infrastructure such as sidewalks, bikeways, and transit. The result is a significant increase in the number of federally-funded transportation projects in the greater Nashville region that provide opportunities for active transportation trips.