Protein & Strength/Power Athletes

Protein & Strength/Power Athletes Effect of Protein Intake on Strength, Body Composition and Endocrine Changes in Strength/Power Athletes 18 10/11/09 Purpose  Primary Purpose Examine whether protein intakes above recommended levels ( > 2.0 g/kg/day) provide strength and body composition improvements in strength/power athletes  Secondary Purpose Examine the effect of varying protein intakes on resting hormonal concentrations * Recommended Level of Protein Intake: 1.6 – 1.8 g/kg/day Subjects  23 males  Collegiate strength/power athletes  Inclusion Criteria  At least 2 years of resistance training experience  Exclusion Criteria:  Subjects using any anabolic agents 6 months prior to onset of study 19 Methods  Subjects Completed:  Resistance training program for 12 weeks  Daily Training Logs  3-day dietary recalls per week Measurements Prior to Training Program & After  Hormone Assessment:  Blood samples obtained  Body composition estimates  Percent fat, bone mineral density, lean tissue During Training Program  Strength Assessment: ○ One-Repetition Maximum (1-RM) Strength Test 20 Methods Based on the average weekly protein intakes determined for the 12 week study Group Daily Protein Intake Number of Subjects Below Recommended Daily Protein Intake (BL) Recommended Daily Protein Intake (RL) Above Recommended Daily Protein Intake (AL) 1.0 – 1.4 g/kg/day 8 1.6 – 1.8 g/kg/day 7 > 2.0 g/kg/day 8 Results Strength Improvements in AL Group RL 1‐RM Bench Press Improvement 42% 1‐RM Bench Squat Improvement 22% BL 35% 63% However, strength improvements observed in the AL group were also NOT statistically significant * AL = Above Recommended Daily Protein Intake 21 Results  Between the groups, no significant difference  daily caloric intake  Δ body mass  Δ lean body mass  Δ percent body fat  on resting hormone concentrations Conclusion/Discussion For collegiate Strength/Power Athletes:  Study does NOT provide support for a protein intake greater than recommended levels  No significant body composition improvements  No significant effect on resting hormone concentrations  Caloric Intake Problem 22 Implication Although elevated protein intake did not produce significantly greater strength improvements… … results suggest that further research is necessary to determine the effect of high protein intake on strength and lean tissue accruement Critique (+)       Variety of references Easy to follow protocol Good summary of existing literature Sufficient detail to replicate the study Unexpected findings explained Potential direction for future studies mentioned (-)      Small sample size Limits on generalizing results Questionable procedure for subject categorization Protein quality – was intake from supplements or food? Caloric intake was below recommended levels for athletes 23 Protein & Supplements Impact of differing protein sources and a creatine containing nutritional formula after 12 weeks of resistance training 24 Purpose To evaluate whether colostrums or an isocaloric and isonitrogenous blend of whey and casein in addition to creatine affects body composition, muscular strength and endurance, and anaerobic performance during resistance-training. Methods Experimental Design The study is a double-blind, placebo controlled, randomized clinical trial with subjects matched according to age and FFM before the study. Subjects  49 apparently healthy subjects, 18-45 years of age  36 are male and 13 are female Familiarization & Testing Sessions Informed consent statements are signed Medical & Exercise History Forms are completed General Physical Examination was completed Completed practice trials of all strength testing and anaerobic capacity equipment Approximately 1 week separated the familiarization session with from the baseline testing session      25 Methods Subjects were assigned to one of four isocaloric and isonitrogenous supplement group. Subjects were instructed to maintain their normal diets. Subjects performed the 1RMs and maximal repetitions to fatigue tests. Subjects completed a anaerobic capacity sprint test on a cycle ergometer. The training program consisted of four workouts per week (2 for upper body and 2 for lower body). Results No Side-effects • No statistically difference in food intakes • Body Composition • • No significant changes for total body water, body mass, % body fat, and bone mineral content. • Significant increases in body mass, DXA total scanned mass, and DXA FFM • Pro/Col, Pro/Cr, and Col/Cr groups had significantly greater increases in comparison with the Pro group for body mass and DXA total scanned mass • Participants who ingested Pro/Cr and Col/Cr had greater gains in DXA FFM than those who ingested Pro. 26 Results  Aerobic Capacity  Significant increase over time for peak power across groups  No changes for total work and fatigue.  No significant peak power, total work, and fatigue index Conclusion • Protein supplementation from whey, casein and colostrum sources during resistance training promotes increase in body mass & FFM in addition to strength. • The combination of whey & casein protein plus creatine or colostrum plus creatine promoted greater increase in FFM compared with protein alone or protein plus colostrim. 27 Critique (+) (-) • Good array of subjects and the conclusion can be generalized in terms of age and gender • The study does not provide additional support of colostrum as an ergogenic agent. • Easy to comprehend • • Consistent with similar studies Accurate calculation of training volume is questionable. Teaching and Communicating the Information 28 Human Ecological Theory Developed by psychologist, Urie Bronfenbrenner  4 levels of the environment   Microsystem: everyday, immediate environment ○ homes, caregivers, friends, and teachers.  Mesosystem: connection between aspects of the microsystem, binding one aspect to another  Exosystem: external influences ○ local government, the community, schools, places for worship, and local media.  Macrosystem: cultural influences Human Ecological Theory Understanding quality of life issues for individual clients is very important  Dietitians- evaluate an individual’s diet and create an appropriate diet plan  Different levels of the environment will each have an impact on an athlete   Diet and health  Athletic performance 29 Human Ecological Theory       Implications central to protein and exercise: Familiarization with the athlete’s lifestyle  On and off the sports ground Be an integral part of the team, establish trust Protein intake, timing, and quality of protein  According to the athlete’s specific needs Flexibility in the dietary regimen  i.e. if the athlete finds it inconvenient to consume higher quality protein, more practical alternatives should be made available Protein is a vital part of a balanced diet, but it is best not to consume in excess or in replacement of other vital nutrients 30