Among nuts, pistachios are considered a rich source of leucine. They are also a good source of antioxidants. These are compounds known to promote muscle protein synthesis and reduce inflammation respectively. Therefore, we hypothesize that pistachios may confer favorable effects to athletes following strenuous exercise.
PURPOSE: to determine if pistachio nut consumption for two weeks prior to and during three days of recovery from vigorous, eccentrically biased exercise improves muscles soreness, vertical jump height and muscle strength in a dose (0, 1.5 oz and 3.0oz per day) dependent manner.
METHODS: Using a randomized, crossover approach, nine active men (N=9), (25.5 ±5yrs, 175.3 ±5.6 cm, 76.0 ± 9.4 kg, VO2 peak= 53.3 ±9.1ml/kg/min) engaged in three, 40-minute downhill runs after 2-weeks of each dose intervention, with a minimum 3-week washout period between trials. Muscle soreness, vertical jump height and muscle strength were assessed pre-exercise (baseline) and 24-hr, 48-hr and 72-hr post exercise, and subjects continued consuming their specified daily dose throughout the recovery period. Data were analyzed using a 3 x 4 repeated measures ANOVA with post-hoc Paired T-tests when appropriate.
RESULTS: Subjective measures of delayed onset muscle soreness for the RTA were significantly higher in the control trial than the 3.0oz/d trial at 72-hr (p<.03). Vertical Jump height decreased 24 hours after the downhill run for the 0oz/d trial only (p<.03; 95% CI∆ 0.12 to 1.38). Although no significant differences were detected between the 0 oz/d trial and the other trials, average muscle torque during leg flexion at two different speeds was higher (p<0.05) at the 48 hour time-point for the 3.0 oz/d trial versus the 1.5 oz/d trial.
CONCLUSIONS: Preliminary analysis suggest that pistachio consumption tended to promote several markers of recovery; however, since blinding research participants was not possible, we cannot eliminate the potential role that a placebo effect may play.