title: Nutrition and resistance exercise during reconditioning from unloading.
abstract: BACKGROUND
  The recovery of muscle size and function following musculoskeletal unloading has received little attention in the scientific literature. Nutritional factors such as total energy, protein intake, and the pre- and/or post-exercise consumption of amino acid-carbohydrate (AACHO) have been shown to be important for enhancing training adaptations in recreational exercisers.
  
  
  OBJECTIVE
  A preliminary study was conducted to explore the interaction between nutrition and resistance exercise during reconditioning from unloading.
  
  
  METHODS
  Muscle CSA, strength, and endurance were measured during a control period following 30 d of unilateral lower limb suspension (Post-ULLS) and after 18 d of reconditioning (ReCon). Six participants consumed either AACHO (979 kJ, 36 g carbohydrate, 22.5 g protein) or placebo (PLAC) prior to resistance exercise (3 d x wk(-1)) during reconditioning. Total daily energy and macronutrient intake were evaluated from dietary journals.
  
  
  RESULTS
  From Post-ULLS to ReCon, muscle endurance increased 1.1 +/- 0.6 min in AACHO and decreased 1.3 +/- 0.7 min in PLAC. Muscle CSA (6 +/- 2 vs. 5 +/- 3 cm2) and strength (105 +/- 53 vs. 81 +/- 37 N) increased similarly in AACHO and PLAC, respectively. When groups were pooled there was a significant correlation between daily protein intake and the recovery of muscle CSA (r = 0.81).
  
  
  CONCLUSIONS
  Although our findings are preliminary, timing AACHO intake during reconditioning was beneficial for muscular endurance, while overall protein intake was associated with increased muscle size. A systematic evaluation into the synergistic relationship between nutrition and exercise during muscular recovery from prolonged unloading is warranted.
authors.affiliation: Department of Exercise Science, Syracuse University, Syracuse, NY 13244, USA. kjhackne@syr.edu
authors.forename: Kyle J
authors.initials: KJ
authors.lastname: Hackney
authors.forename: Summer B
authors.initials: SB
authors.lastname: Cook
authors.forename: Lori L
authors.initials: LL
authors.lastname: Ploutz-Snyder
mesh_terms: D004032:Diet; D015444:Exercise / Q000502:physiology*; D005260:Female; D019417:Hindlimb Suspension / Q000379:methods*; D006801:Humans; D008297:Male; D053580:Muscle Strength / Q000502:physiology*; D018482:Muscle, Skeletal / Q000502:physiology*; D009751:Nutritional Requirements; D010807:Physical Endurance / Q000502:physiology*; D055815:Young Adult