The Effects of Pre- and Post-Exercise Whey vs. Casein Protein Consumption on Body Composition and Performance Measures in Collegiate Female Athletes

Two of the most popular forms of protein on the market are whey and casein. Both proteins are derived from milk however the two differ concerning their absorption in the body. This difference between whey and casein proteins could affect the response seen in conjunction with training. PURPOSE: To investigate the potential effects of two types of protein ingestion in conjunction with a controlled resistance training program utilizing college female basketball players. METHODS: 16 NCAA Division III female basketball players were matched according to weight and double-blind randomly assigned to consume 24 grams whey protein (WP) (N = 8, 20 ± 1.9 years, 158 ± 27.3 cm, 66 ± 4.9 kg, 27 ± 4.9 %BF) or 24 grams casein protein (CP) (N = 8, 21 ± 2.8 years, 153 ± 2.9 cm, 68 ± 2.9 kg, 25 ± 5.7 %BF) pre- and post-exercise for eight weeks. Subjects participated in a supervised 4-day per week undulating periodized training program. At 0, 4, and 8 weeks, subjects underwent DEXA body composition analysis. At 0 and 8 weeks subjects underwent 1RM strength, muscle endurance, vertical jump, 5-10-5 and broad jump testing sessions. Data analysis using repeated measures ANOVA are presented as mean ± SD changes from baseline after 60 days. RESULTS: No significant group x time interaction effects were observed among groups in changes in any variable (p \u3e 0.05). A significant time effect was observed for body fat (WP: -2 ± 1.1 %BF; CP: -1 ± 1.6 %BF, p \u3c 0.001), lean mass (WP: 1.5 ± 1 kg; CP: 1.4 ± 1 kg, p \u3c 0.001), fat mass (WP: -1.3 ± 1.2 kg; CP: -0.6 ± 1.4 kg, p \u3c 0.001), leg press 1RM (WP: 88.7 ± 43.9 kg; CP: 90 ± 48.5 kg, p \u3c 0.001), bench press 1RM (WP: 7.5 ± 4.6 kg; CP: 4.3 ±4.5 kg, p = 0.01), vertical jump (WP: 1.6 ± 0.74 in; CP: 1.4 ± 3 in, p \u3c 0.001), 5-10-5 (WP: -0.3 ± 0.2 sec; CP: -0.09 ± 0.42 sec, p \u3c 0.001), and broad jump (WP: 4.1 ± 2.6 in; CP: 5.1 ± 2.8 in, p \u3c 0.001). CONCLUSION: The combination of a controlled undulating resistance training program with pre- and post-exercise protein supplementation is capable of inducing significant changes in performance and body composition. There does not appear to be a difference in the performance enhancing effects of whey versus casein proteins

Effects of Pre- and Post-Exercise Protein vs. Carbohydrate Ingestion on Training Adaptations in Collegiate Female Athletes

The role of nutrient timing both before and after daily training sessions is now a major part of the nutritional recommendations for athletes to maximize training adaptations. However, there still exists some questions on the ideal macronutrient selection for these pre- and post-workout meals. PURPOSE: To investigate the potential effects of protein vs. carbohydrate ingestion in collegiate female basketball players. METHODS: 14 (20.2 ± 1.4 years, 169.4 ± 5.8 cm, 67.5 ± 6.1 kg, 27.1 ± 4.4 %BF) NCAA Division III female basketball players were matched by weight and randomly assigned in a double-blind manner to consume 24 grms whey protein (WP) or 24 grms maltodextrin (MD) pre- and post-exercise for eight weeks. Subjects participated in a supervised 4-day per week undulating periodized resistance and anaerobic training program. At 0 and 8-weeks, subjects underwent DEXA body composition analysis and upper- and lower-body 1RM strength, vertical jump, 5-10-5, and broad jump testing. Data were analyzed using repeated measures ANOVA (p≤0.05) and are presented as mean ± SD changes. RESULTS: Significant group x time interaction effects were observed among groups for bench press 1RM (p = 0.043) and DEXA lean mass (p = 0.026) indicating that the WP group resulted in a more substantial training adaptations over the MD group. A significant time effect (p \u3c 0.05) was observed for DEXA %BF (%change: -4.87 ± 4%), DEXA fat mass (%change: -4.33 ± 5%), leg press 1RM (%change: 13.57 ± 7%), vertical jump (%change: 9.95 ± 6%), 5-10-5 (%change: -3.1 ± 2%), and broad jump (%change: 3.9 ± 4%) suggesting that the stimulus of the training protocol was adequate to promote anaerobic physiological adaptations. CONCLUSION: In regards to nutrient timing, our results suggest that whey protein ingestion both pre- and post-training is a greater stimulus for increases in lean mass in female collegiate anaerobic athletes as compared to the ingestion of carbohydrates. This translated into a significant difference in upper body 1RM strength, however, despite significant training adaptations occurring over the 8 week trial, no significant differences occurred in lower body strength, vertical and broad jump, and 5-10-5 time between WP and MD groups

Pediatricians' weight assessment and obesity management practices

<p>Abstract</p> <p>Background</p> <p>Clinician adherence to obesity screening guidelines from United States health agencies remains suboptimal. This study explored how personal and career demographics influence pediatricians' weight assessment and management practices.</p> <p>Methods</p> <p>A web-based survey was distributed to U.S. pediatricians. Respondents were asked to identify the weight status of photographed children and about their weight assessment and management practices. Associations between career and personal demographic variables and pediatricians' weight perceptions, weight assessment and management practices were evaluated using univariate and multivariate modeling.</p> <p>Results</p> <p>3,633 pediatric medical providers correctly identified the weight status of children at a median rate of 58%. The majority of pediatric clinicians were white, female, and of normal weight status with more than 10 years clinical experience. Experienced pediatric medical providers were less likely than younger colleagues to correctly identify the weight status of pictured children and were also less likely to know and use BMI criteria for assessing weight status. General pediatricians were more likely than subspecialty practitioners to provide diverse interventions for weight management. Non-white and Hispanic general practitioners were more likely than counterparts to consider cultural approaches to weight management.</p> <p>Conclusion</p> <p>Pediatricians' perceptions of children's weight and their weight assessment and management practices are influenced by career and personal characteristics. Objective criteria and clinical guidelines should be uniformly applied by pediatricians to screen for and manage pediatric obesity.</p

The Defective Prophage Pool of Escherichia coli O157: Prophage–Prophage Interactions Potentiate Horizontal Transfer of Virulence Determinants

Bacteriophages are major genetic factors promoting horizontal gene transfer (HGT) between bacteria. Their roles in dynamic bacterial genome evolution have been increasingly highlighted by the fact that many sequenced bacterial genomes contain multiple prophages carrying a wide range of genes. Enterohemorrhagic Escherichia coli O157 is the most striking case. A sequenced strain (O157 Sakai) possesses 18 prophages (Sp1–Sp18) that encode numerous genes related to O157 virulence, including those for two potent cytotoxins, Shiga toxins (Stx) 1 and 2. However, most of these prophages appeared to contain multiple genetic defects. To understand whether these defective prophages have the potential to act as mobile genetic elements to spread virulence determinants, we looked closely at the Sp1–Sp18 sequences, defined the genetic defects of each Sp, and then systematically analyzed all Sps for their biological activities. We show that many of the defective prophages, including the Stx1 phage, are inducible and released from O157 cells as particulate DNA. In fact, some prophages can even be transferred to other E. coli strains. We also show that new Stx1 phages are generated by recombination between the Stx1 and Stx2 phage genomes. The results indicate that these defective prophages are not simply genetic remnants generated in the course of O157 evolution, but rather genetic elements with a high potential for disseminating virulence-related genes and other genetic traits to other bacteria. We speculate that recombination and various other types of inter-prophage interactions in the O157 prophage pool potentiate such activities. Our data provide new insights into the potential activities of the defective prophages embedded in bacterial genomes and lead to the formulation of a novel concept of inter-prophage interactions in defective prophage communities