title: Supplementation with a polyphenolic blend improves post-exercise strength recovery and muscle soreness.
abstract: BACKGROUND
  Exercise can initiate a cascade of inflammatory and oxidative stress-related events leading to delayed onset muscle soreness. Polyphenols possess antioxidant and anti-inflammatory properties.
  
  
  OBJECTIVE
  The current study examined the effects of a proprietary polyphenolic blend (PB), containing catechins and theaflavins, on exercise performance and recovery following an eccentric exercise challenge.
  
  
  METHODS
  Male participants (18-35 years of age) received placebo or PB at a low dose (PB-L, 1,000 mg/d) or high dose (PB-H, 2,000 mg/d) for 13 weeks. During the 13th week of supplementation, participants completed an eccentric exercise (40 min downhill treadmill run) followed by a strength assessment (peak torque on isokinetic leg extensions) pre-exercise, and 24, 48, and 96 h post-exercise. Muscle soreness (subjective questionnaire), markers of muscle stress (cortisol and creatine phosphokinase [CK]), and antioxidant capacity (ferric reducing ability of plasma [FRAP]) were also assessed.
  
  
  RESULTS
  PB-H attenuated the decrease in peak torque observed in the placebo group from pre-exercise to 48 h (p=0.012) and 96 h (p=0.003) post-exercise. At 48 h post-exercise, PB-H reduced whole body and hamstring soreness (p=0.029) versus placebo. Chronic consumption of PB improved serum FRAP (p=0.039). As expected, serum cortisol and CK increased from pre- to post-exercise in all groups; however, by 96 h, cortisol and CK levels returned to pre-exercise levels following PB supplementation. At 96 h, the change in cortisol from pre- to post-exercise was significantly greater in placebo versus PB-H (p=0.039).
  
  
  CONCLUSIONS
  These findings show that chronic consumption of PB improved antioxidant status, reduced markers of muscle stress, and promoted strength recovery post-exercise.
authors.affiliation: Kemin Foods, LC, Des Moines, IA, USA; kelli.herrlinger@kemin.com.
authors.forename: Kelli A
authors.initials: KA
authors.lastname: Herrlinger
authors.affiliation: Kemin Foods, LC, Des Moines, IA, USA.
authors.forename: Diana M
authors.initials: DM
authors.lastname: Chirouzes
authors.affiliation: Kemin Foods, LC, Des Moines, IA, USA.
authors.forename: Michael A
authors.initials: MA
authors.lastname: Ceddia
keywords: antioxidant; catechins; cortisol; creatine phosphokinase; delayed onset muscle soreness; strength; theaflavins