The creatine content of Creatine Serum™ and the change in the plasma concentration with ingestion of a single dose

Three samples of Creatine Serum? ATP Advantage from Muscle Marketing USA, Inc. were assayed for creatine by two different techniques by four independent laboratories, and for creatinine by two different techniques by two laboratories. A further sample was assayed for phosphorylcreatine. Dry weight and total nitrogen were also analysed. Six male volunteers ingested in random order, over 3 weeks: (A) water; (B) 2.5?g creatine monohydrate (Cr?·?H₂O) in solution; and (C) 5?ml Creatine Serum? (reportedly containing an equivalent amount of Cr?·?H₂O). Blood samples were collected before and up to 8?h after each treatment and plasma was analysed for creatine and creatinine. Eight-hour urine samples were analysed for creatine. Ingestion of 2.5?g creatine monohydrate in solution resulted in a significant increase in plasma creatine (from 59.1±11.8?μmol?·?l^?1 to 245.3±74.6?μM μmol?·?l^?1; mean±s) and urinary creatine excretion. No increase in plasma or urinary creatine or creatinine was found on ingestion of Creatine Serum? or water. Analysis showed 5?ml of Creatine Serum? to contain <10?mg Cr?·?H₂O and approximately 90?mg creatinine. Phosphorylcreatine was not detectable and only a trace amount of phosphorous was present. Total nitrogen analysis ruled out significant amounts of other forms of creatine. We conclude that the trace amounts of creatine in the product would be too little to affect the muscle content even with multiple dosing.     

The influence of fear appeals,message design,and masculinity on men's motivation to perform the testicular self‐exam

Despite the significant threat men face for contracting testicular cancer, most men remain completely unaware of this risk. Moreover, men are not regularly performing the testicular self‐exam (TSE) in order to detect this form of cancer in their bodies. The current study attempted to assess whether fear appeals targeted at men will motivate them to begin regular performance of the TSE. Additionally, the influence of message design and masculinity was also tested. Results indicate messages that follow the direction of Witte's (1992, 1994) Extended Parallel Process Model and promote both high threat and high efficacy are successful in increasing men's intentions to perform the TSE. Implications of these findings are discussed.     

The role of coach-athlete relationship quality in team sport athletes’ psychophysiological exhaustion: implications for physical and cognitive performance

The present study aimed to examine associations between the quality of the coach-athlete relationship and athlete exhaustion by assessing physiological and cognitive consequences. Male and female athletes (N = 82) representing seven teams across four different sports, participated in a quasi-experimental study measuring physical performance on a 5-meter multiple shuttle test, followed by a Stroop test to assess cognitive performance. Participants provided saliva samples measuring cortisol as a biomarker of acute stress response and completed questionnaires measuring exhaustion, and coach-athlete relationship quality. Structural equation modelling revealed a positive relationship between the quality of the coach-athlete relationship and Stroop performance, and negative relationships between the quality of the coach-athlete relationship and cortisol responses to high-intensity exercise, cognitive testing, and exhaustion. The study supports previous research on socio-cognitive correlates of athlete exhaustion by highlighting associations with the quality of the coach-athlete relationship.