title: Effects of protein-carbohydrate supplementation on immunity and resistance training outcomes: a double-blind, randomized, controlled clinical trial.
abstract: OBJECTIVE
  To examine the impact of ingesting hydrolyzed beef protein, whey protein, and carbohydrate on resistance training outcomes, body composition, muscle thickness, blood indices of health and salivary human neutrophil peptides (HNP1-3), as reference of humoral immunity followed an 8-week resistance training program in college athletes.
  
  
  METHODS
  Twenty-seven recreationally physically active males and females (n = 9 per treatment) were randomly assigned to one of the three groups: hydrolyzed beef protein, whey protein, or non-protein isoenergetic carbohydrate. Treatment consisted of ingesting 20 g of supplement, mixed with orange juice, once a day immediately post-workout or before breakfast on non-training days. Measurements were performed pre- and post-intervention on total load (kg) lifted at the first and last workout, body composition (via plethysmography) vastus medialis thickness (mm) (via ultrasonography), and blood indices of health. Salivary HNP1-3 were determined before and after performing the first and last workout.
  
  
  RESULTS
  Salivary concentration and secretion rates of the HNP1-3 decreased in the beef condition only from pre-first-workout (1.90 ± 0.83 μg/mL; 2.95 ± 2.83 μg/min, respectively) to pre-last-workout (0.92 ± 0.63 μg/mL, p = 0.025, d = 1.03; 0.76 ± 0.74 μg/min, p = 0.049, d = 0.95), and post-last-workout (0.95 ± 0.60 μg/mL, p = 0.032, d = 1.00; 0.59 ± 0.52 μg/min, p = 0.027, d = 1.02). No other significant differences between groups were observed.
  
  
  CONCLUSIONS
  Supplementation with a carbohydrate-protein beverage may support resistance training outcomes in a comparable way as the ingestion of only carbohydrate. Furthermore, the ingestion of 20 g of hydrolyzed beef protein resulted in a decreased level and secretion rates of the HNP1-3 from baseline with no negative effect on blood indices of health.
authors.affiliation: Department of Life and Sports Sciences, University of Greenwich, Chatham Maritime, UK. f.j.naclerio@gre.ac.uk.
authors.forename: Fernando
authors.initials: F
authors.lastname: Naclerio
authors.affiliation: Clinical Research Institute, Texas Tech University Health Sciences Center, Lubbock, TX, USA.
authors.forename: Eneko
authors.initials: E
authors.lastname: Larumbe-Zabala
authors.affiliation: Department of Life and Sports Sciences, University of Greenwich, Chatham Maritime, UK.
authors.forename: Nadia
authors.initials: N
authors.lastname: Ashrafi
authors.affiliation: Department of Life and Sports Sciences, University of Greenwich, Chatham Maritime, UK.
authors.forename: Marco
authors.initials: M
authors.lastname: Seijo
authors.affiliation: Department of Life and Sports Sciences, University of Greenwich, Chatham Maritime, UK.
authors.forename: Birthe
authors.initials: B
authors.lastname: Nielsen
authors.affiliation: Faculty of Science Engineering and Computing, Kingston University, London, UK.
authors.forename: Judith
authors.initials: J
authors.lastname: Allgrove
authors.affiliation: Exercise Science and Nutrition Laboratory, Texas A&M University, College Station, TX, USA.
authors.forename: Conrad P
authors.initials: CP
authors.lastname: Earnest
mesh_terms: D000293:Adolescent; D000328:Adult; D056352:Athletes; D001823:Body Composition / Q000187:drug effects*; D002241:Carbohydrates / Q000008:administration & dosage*; D019587:Dietary Supplements; D004311:Double-Blind Method; D005260:Female; D006801:Humans; D007107:Immune System / Q000187:drug effects*; D008297:Male; D053580:Muscle Strength / Q000187:drug effects* / Q000502:physiology*; D018482:Muscle, Skeletal / Q000187:drug effects* / Q000502:physiology; D011506:Proteins / Q000008:administration & dosage*; D052097:Quadriceps Muscle / Q000378:metabolism; D055070:Resistance Training / Q000379:methods; D055815:Young Adult
chemical_list: D002241:Carbohydrates; D011506:Proteins
keywords: Blood indices of health; Body composition; Immune status; Muscle thickness; Strength performance