title: Montmorency cherry juice reduces muscle damage caused by intensive strength exercise.
abstract: OBJECTIVE
  Montmorency cherries contain high levels of polyphenolic compounds including flavonoids and anthocyanins possessing antioxidant and anti-inflammatory effects. We investigated whether the effects of intensive unilateral leg exercise on oxidative damage and muscle function were attenuated by consumption of a Montmorency cherry juice concentrate using a crossover experimental design.
  
  
  METHODS
  Ten well-trained male overnight-fasted athletes completed two trials of 10 sets of 10 single-leg knee extensions at 80% one-repetition maximum. Trials were separated by 2 wk, and alternate legs were used in each trial. Participants consumed each supplement (CherryActive® (CA) or isoenergetic fruit concentrate (FC)) for 7 d before and 48 h after exercise. Knee extension maximum voluntary contractions (MVC) were performed before, immediately after, and 24 and 48 h after the damaging exercise. Venous blood samples were collected at each time point, and serum was analyzed for creatine kinase (CK) activity, nitrotyrosine, high-sensitivity C-reactive protein, total antioxidant capacity, and protein carbonyls (PC). Two-way repeated-measures ANOVA were used for statistical analysis of the data.
  
  
  RESULTS
  MVC force recovery was significantly faster (24 h: CA 90.9% ± 4.2% of initial MVC vs FC 84.9% ± 3.4% of initial MVC; 48 h: CA 92.9% ± 3.3% of initial MVC vs FC 88.5% ± 2.9% of initial MVC (mean ± SEM); P < 0.05) after CA than FC consumption. Only serum CK and PC increased significantly from baseline, peaking 24 h after exercise (P < 0.001). The exercise-induced increase in CK activity was not different between trials. However, both the percentage (24 h after: CA 23.8% ± 2.9% vs FC 82.7% ± 11.7%; P = 0.013) and absolute (24 h after: CA 0.31 ± 0.03 nmol·mg(-1) protein vs FC 0.60 ± 0.08 nmol·mg(-1) protein; P = 0.079) increase in PC was lower in CA than FC trials.
  
  
  CONCLUSIONS
  Montmorency cherry juice consumption improved the recovery of isometric muscle strength after intensive exercise perhaps owing to the attenuation of the oxidative damage induced by the damaging exercise.
authors.affiliation: Sports and Exercise Science Research Centre, London South Bank University, London, United Kingdom. bowteljl@lsbu.ac.uk
authors.forename: Joanna L
authors.initials: JL
authors.lastname: Bowtell
authors.forename: David Paul
authors.initials: DP
authors.lastname: Sumners
authors.forename: Amy
authors.initials: A
authors.lastname: Dyer
authors.forename: Patrick
authors.initials: P
authors.lastname: Fox
authors.forename: Katya N
authors.initials: KN
authors.lastname: Mileva
mesh_terms: D000328:Adult; D000975:Antioxidants / Q000378:metabolism; D002097:C-Reactive Protein / Q000378:metabolism; D003402:Creatine Kinase / Q000097:blood; D018592:Cross-Over Studies; D019587:Dietary Supplements; D015444:Exercise / Q000502:physiology; D006801:Humans; D007717:Knee / Q000502:physiology; D008297:Male; D009119:Muscle Contraction / Q000187:drug effects / Q000502:physiology; D018482:Muscle, Skeletal / Q000187:drug effects* / Q000293:injuries* / Q000502:physiology; D018384:Oxidative Stress / Q000187:drug effects; D050050:Protein Carbonylation; D027861:Prunus; D055070:Resistance Training; D014443:Tyrosine / Q000031:analogs & derivatives / Q000097:blood
chemical_list: D000975:Antioxidants; C002744:3-nitrotyrosine; D014443:Tyrosine; D002097:C-Reactive Protein; D003402:Creatine Kinase