Effect of Pistachios on Muscle Recovery
Condition: Muscle Soreness
MeSH terms: Myalgia
Study type: Interventional

Summary: 
      Pistachios are an understudied and often unappreciated functional food. While nuts in general
      have received somewhat more attention for their nutritional properties from researchers,
      practitioners and the media, pistachios often seem to be overlooked. Meanwhile, pistachios
      appear to possess characteristics that suggest that they are likely to impart benefits that
      are equal to and perhaps above and beyond those of average nuts. We intend to explore the
      potential impacts of pistachios on recovery from rigorous exercise in well-trained athletes.
      We hypothesize that feeding 1.5 oz of pistachios will improve exercise recovery as determined
      by a reduction in delayed onset muscle soreness and suppression of markers of muscle damage,
      inflammation and oxidative stress in comparison to water and that the benefits will be
      greater with consumption of 3.0 oz of pistachios.
    

Detailed description: 
      Specific objectives are to determine the dose response to ingestion of pistachios for
      promotion of recovery from vigorous exercise. To accomplish this, investigators will examined
      whether regular consumption of pistachios followed by pistachio feeding at two different
      doses (1.5 and 3.0 oz) during the recovery period following eccentrically biased exercise
      (downhill running) promotes enhanced recovery as measured by muscle soreness, markers of
      muscle damage, and status for inflammation and oxidative stress in comparison to a control
      feeding of water in endurance-trained runners (18-35 years of age).

      Study Design

      A cross-over design performed in random order will be utilized in which participants will
      complete 3 trials separated by at least 3-4 weeks. At each testing site, 28 well-trained,
      competitive male athletes will be recruited. Participants will be required to participate in
      at least 5 hours of vigorous exercise per week and to actively compete in sport. Exclusion
      criteria include smoking, medications known to impact inflammation, musculoskeletal
      limitations and use of supplements known to impact antioxidant or inflammatory status within
      1 month of participation.

      Approach/Methods

      Participants will consume water only, water plus 1.5 oz of pistachios, or water plus 3.0 oz
      of pistachios daily for 2 weeks during 3 separate trials in a randomized, cross-over fashion.
      Subjects will then report to the laboratory following an overnight fast and after abstaining
      from strenuous exercise for 2 days. Fasting blood samples will be collected and participants
      will complete a 40-min downhill run at -10% grade at 65-70% of a predetermined VO2max. A
      recovery serving of water or water along with one of the doses of pistachios will be
      provided. Antecubital blood samples will be collected before the bout of exercise and 24, 48,
      and 72 hours afterward. Muscle soreness will be assessed at each timepoint as well. Vertical
      jump will be assessed prior to the exercise bout and at each recovery timepoint. Daily
      consumption of the pistachios will continue during the 72-hour recovery period.

      All participants will receive individualized diet counseling by investigators on a biweekly
      basis. An initial 3-day food record will be analyzed using dietary software to serve as a
      starting point for which the diet counseling will be based. Each participant will be provided
      with an individualized plan outlining their required macronutrient and micronutrient intakes
      (including antioxidants) in grams corresponding to their habitual diet as determined by the
      3-day diet diary. Once per week, participants will provide a 3-day food record to track
      compliance with the nutrition protocol. All participants will be provided with feedback in
      their next biweekly private counseling session. To ensure that the results were due, as much
      as possible, to the differing dietary intervention (pistachio ingestion), participants will
      be instructed not to take any vitamin or mineral supplements during the study.

      Data will be analyzed using a repeated measures ANOVA followed by paired T-tests as post-hoc
      tests using SPSS. Statistical significance will accepted at P<0.05.
    

Intervention name(s): Water; 1.5 oz Pistachios; 3.0 oz Pistachios
Intervention type(s): Dietary Supplement; Dietary Supplement; Dietary Supplement
Intervention description(s): Participants will consume water only; Participants will consume water plus 1.5 oz of pistachios as the intervention; Participants will consume water plus 3.0 oz of pistachios as the intervention
Allocation: Randomized
Intervention model: Crossover Assignment
Masking: None (Open Label)
Primary purpose: Supportive Care