The current study assessed the construct validity of the Drive for Muscularity Scale (DMS; D. R.McCreary & D. K. Sasse, 2000) using both lower and higher order exploratory factor analysis (EFA). In a sample of male and female high school and college students, lower order EFAs showed that a 2-factor structure emerged for men (muscularity attitudes and behaviors), but not for women, although 11 of the 15 items overlapped across gender. A higher order EFA using the male 2-factor structure revealed the presence of a single, higher order DMS factor in both genders. It is argued that the overall DMS score can be used in samples of both men and women. However, the attitude and behavioral DMS subscales can be used validly only in men.

Collective efficacy has received little research attention since its inception. Therefore, the objectives of this study were to develop a theory-based measure of collective efficacy and determine its relationship with another group phenomenon-group cohesion. Volleyball players (N = 70) completed questionnaires designed to assess their perceptions of their teams' confidence in skills and abilities related to group tasks and processes. Several important outcomes emerged. First, a theory-based measure of collective efficacy was developed, and initial psychometric properties were established. Second, various aspects of collective efficacy were found to be positively correlated with group cohesion. Third, only certain aspects of a multidimensional collective efficacy measure were found to be predictive of task-related aspects of team cohesion. When considered together, the findings represent a promising step toward the investigation of collective efficacy.

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This study's primary purpose was to examine the degree to which individual perceptions of cohesiveness reflect shared beliefs in sport teams. The secondary purposes were to examine how the type of cohesion, the task interactive nature of the group, and the absolute level of cohesion relate to the index of agreement. Teams (n = 192 containing 2,107 athletes) were tested on the Group Environment Questionnaire. Index of agreement values were greater for the group integration (GI) manifestations of cohesiveness (GI-task, rwg(j) = .721; GI-social,rwg(j) = .694) than for the individual attractions to the group (ATG) manifestations (ATG-task, rwg(j) = .621; ATG-social, rwg(j) = .563). No differences were found for interactive versus coactive/independent sport teams. A positive relationship was observed between the absolute level of cohesiveness and the index of agreement. Results were discussed in terms of their implication for the aggregation of individual perceptions of cohesion to represent the group construct.

Consuming sugar-free Red Bull energy drink before exercise has become increasingly popular among exercising individuals. The main purported active ingredient in sugar-free Red Bull is caffeine, which has been shown to increase aerobic exercise performance. The purpose of this study was to determine the effects of sugar-free Red Bull energy drink on high-intensity run time-to-exhaustion in young adults. Physically active university students (n = 17, 9 men, 8 woman; 21 +/- 4 years, 73.4 +/- 3.1 kg, 175.1 +/- 3.2 cm) participated in a double-blind, crossover, repeated-measures study where they were randomized to supplement with sugar-free Red Bull (2 mg x kg(-1) body mass caffeine or approximately 147 mg caffeine; 4 kcal/250 mL) and noncaffeinated, sugar-free placebo (lemon-lime flavored soft drink, tonic water, lime juice; 4 kcal/250 mL) separated by 7 days. Exercise capacity was assessed by a run time-to-exhaustion test at 80% Vo2max, perceived exertion was assessed immediately after exercise, and blood lactate was measured before and after exercise. There were no differences in run time-to-exhaustion (Red Bull: 12.6 +/- 3.8 minutes, placebo: 11.8 +/- 3.4 minutes), perceived exertion (Red Bull: 17.1 +/- 2.0, placebo: 16.6 +/- 1.8), or blood lactate between groups. In conclusion, sugar-free Red Bull energy drink did not influence high-intensity run time-to-exhaustion in young adults.