Bromelain, Papain, and Exercise Recovery

Protease supplementation has been purported to reduce the damaging effects of eccentric exercise and accelerate recovery of muscle function, possibly by regulating inflammation.

PURPOSE:: To determine the effectiveness of protease supplementation in attenuating eccentric exercise-induced skeletal muscle damage and inflammation.

METHODS:: After standard physical and hemodynamic assessment and fasting venous blood samples, subjects performed isokinetic extension/flexion of the quadriceps group on a Biodex isokinetic dynamometer at 60 degrees .s, followed by V O2max testing. Subjects were randomly assigned to consume 5.83 g daily of either a cellulose placebo (N = 15; 22.27 +/- 3.33 yr, 71.17 +/- 2.91 inches, 179.4 +/- 24.05 lb, 50.55 +/- 5.66 mL.kg.min) or a proteolytic supplement containing fungal proteases, bromelain, and papain (N = 14; 22.85 +/- 5.9 yr, 70.0 +/- 2.67 inches, 173.11 +/- 29.94 lb, 49.69 +/- 6.15 mL.kg.min) for a period of 21 d. After the supplementation period, subjects donated blood samples before performing a 45-min downhill (-17.5%) treadmill protocol at 60% of V O2max. An additional four blood draws and three muscle function tests were performed during the next 48 h. Blood was analyzed using standard hematology and clinical chemistry, enzyme-linked immunosorbent assay, and bead array. Blood data were analyzed using multivariate analysis of variance (MANOVA) with repeated measures, whereas Biodex data were analyzed using a MANOVA on %Delta values.

RESULTS:: Significant group differences (T1-T3, P = 0.033; T1-T4, P = 0.043) and another strong trend (T1-3 h, P = 0.055) were observed for flexion (peak torque %Delta at 60 degrees .s) indicating higher force production in the protease group. Significant group x time interactions (P < 0.05) were observed, including elevations in circulating eosinophils and basophils in the protease group coinciding with lower levels of serum cyclooxygenase 2, interleukin 6, and interleukin 12 in this group.

CONCLUSIONS:: Protease supplementation seems to attenuate muscle strength losses after eccentric exercise by regulating leukocyte activity and inflammation.