Almond Supplementation and Exercise Recovery
Condition: Muscular Injury
Study type: Interventional

Summary: 
      The PURPOSE of this study is to see if eating almonds for four weeks will reduce muscle
      damage, soreness, and inflammation during several days of recovery from eccentric exercise.
    

Detailed description: 
      This will be the first study to determine if 4-weeks ingestion of nutrient-dense almonds
      improves feelings of energy and vitality, and mitigates post-exercise inflammation (plasma
      cytokine and oxylipin levels), muscle soreness, and muscle damage. An acute 90-minute bout of
      eccentric exercise will be used to induce muscle damage and inflammation in a group of 60
      relatively untrained male and female adults (ages 30-65 years). Using a randomized, parallel
      group design, almond supplementation (57 g/d) for a 4-week period prior to the eccentric
      exercise challenge will be investigated as a countermeasure strategy to exercise-induced
      muscle damage and inflammation. The control group will ingest a calorie-matched common snack
      (cereal bars). To improve the potential for capturing an intervention effect, advanced mass
      spectrometry procedures will be utilized to measure changes in 70 different oxylipins and
      lipid mediators that are involved in regulating inflammation. C-reactive protein (CRP), six
      inflammatory cytokines, and muscle damage biomarkers will also be measured. Blood samples (7
      total) will be collected before and after the 4-week supplementation period, and then daily
      during 5 days of recovery from the eccentric exercise bout. The Profile of Mood States (POMS)
      will be used to measure mood state and specific domains including vigor or activity, and
      fatigue or inertia. Exercise performance will be measured each time a blood sample is
      collected using a comprehensive battery that includes vertical jump, leg/back muscle
      strength, bench press muscle endurance, and anaerobic power (30-second Wingate test).

      Participants will be randomized to the almond or typical snack (cereal bars) supplement
      groups. The parallel group design is being utilized in this study because of the "repeat
      exercise bout" effect (i.e., post-exercise muscle damage and inflammation are reduced when
      the same bout is repeated within days and weeks of the first bout). Participants will come to
      the lab at 7:00 am at the beginning of the 4-week supplementation period, and then Monday
      (eccentric exercise bout) and Tuesday through Friday (recovery) in an overnight fasted state.
      The 4-week supplementation period was based on practical issues related to the research
      design. A 4-week almond supplementation period was commonly used in prior studies and was
      sufficient to demonstrate favorable blood lipid changes relative to control conditions.

      Seven blood samples will be collected and analyzed for various measures of muscle damage,
      oxylipins, and inflammation. After each of the blood draws, participants will complete the
      POMS (energy, vitality) and provide a muscle soreness rating (DOMS). Physical activity will
      be monitored during the entire study using the International Physical Activity Questionnaire
      (IPAQ). The IPAQ was developed to measure health-related physical activity (PA) in
      populations. The short version of the IPAQ has been tested extensively and is now used in
      many international studies.

      Study participants will come to the performance lab for orientation to the testing
      procedures. This will include a review of the consent form, completion of basic
      questionnaires, and an introduction to the eccentric muscle exercise bout and the
      strength/power performance testing protocol (about 1.5 hours) (visit #1). This will be
      followed by another lab session for pre-study measurements and sample collection with
      subjects in an overnight fasted state (visit #2) (see description below). A 3-day food record
      will be collected during the end of the 4-week supplementation period to assess the
      background diet.

      Study participants will have to agree to 5 other lab visits during a one-week period (all
      overnight fasted condition). These lab visits will start at 7:00 am on Monday, with morning
      visits at 7:00 am on Tuesday through Friday. At each of the 5 lab visits, study participants
      will come to the lab at 7:00 am not having consumed food or beverages (other than water) for
      at least the previous 9 hours, and having abstained from vigorous exercise for at least the
      previous 24-48 hours. The Monday session will take about 2.5 hours (7:00 to 9:30 am), and the
      Tuesday through Friday sessions will take about 30-45 minutes each. The total amount of time
      participants will be asked to volunteer for this study is about 8-9 hours at the performance
      lab.

      Participants will be randomized to almond or snack groups, and provided a 4-weeks supply of
      supplements. Participants in the almond group will consume 57 g almonds each day in split
      doses (half in the morning, half in the afternoon). Participants in the snack group will
      ingest a matched calorie, common snack bar in split doses (324 calories/day, Nutri-Grain
      cereal bars, 120 kcal each).

      The daily dose of almonds (57 g) and just under 3 Nutri-Grain cereal bars will provide a
      distinct difference in nutrient intake. A serving of 57 g of almonds has 324 calories with 12
      g of protein, 28 g of fat (17 g from monounsaturated, 6.6 g from polyunsaturated, 2.6 g from
      saturated), 12 g of carbohydrates and 6.6 g of fiber, 160 mg total polyphenols, and
      significant amounts of vitamin E (96% RDA), magnesium, manganese, copper, and other minerals.

      Baseline Testing (Visit #2) Participants will provide a blood sample using standard
      phlebotomy procedures. Participants will also provide a spot urine sample, with instructions
      to capture a mid-stream urine sample in a disposable urine cup. Spot urine samples provide
      valid metabolite data as indicators of dietary intake. Height, body weight, and body
      composition will be measured in a private section of the lab. Bioelectrical impedance (BIA)
      using the seca BIA scale will be used to assess body composition (i.e., the percent of body
      weight that is fat tissue) and body weight. Participants will remove shoes and socks and
      stand with bare feet on the seca scale for about 7-10 seconds while grasping side rails with
      your hands. Percent body fat will also be measured using the BodPod. Participants will sit
      inside the BodPod with a tight-fitting swim suit for about 10 minutes while body fat is
      calculated. The Profile of Mood States (POMS) will be administered. Delayed onset of muscle
      soreness (DOMS) will be assessed using a 1-10 scale.

      Participants will perform some light exercises to warm up, followed by five muscle function
      tests: vertical jump, bench press, leg-back strength, 60-yard shuttle run test, and anaerobic
      power through the 30-second Wingate test.

        1. Vertical jump: Participants will first stand erect with the feet flat on the floor and
           reach as high as possible with both arms and hands (standing reach height). Participants
           will then squat down and jump as high as possible with one arm and hand, and tap the
           measuring device on the Vertec vertical jump apparatus (jump height). This will be
           repeated three times, with the best score recorded as the difference between the jump
           and standing reach heights.

        2. Bench press to exhaustion at 50%/75%: Participants will lie down supine on a bench, and
           with spotters standing on either side attempt to bench press a weighted bar equal to 75%
           (males) or 50% (females) body weight as many times as possible (to a metronome set at 60
           beats/min or 30 lifts/min). The bar must touch a foam block on the chest lightly in the
           down position, and the arms must be straight in the up position.

        3. Leg-Back Strength: Leg/lower back strength will be assessed with a dynamometer. With the
           legs slightly bent at the knee, participants will grasp a bar attached via a chain and a
           force measuring device with straight arms, and then lift up with maximal effort for
           several seconds. This will measure the isometric strength of both legs and back, and
           will be repeated three times.

        4. 30-Second Wingate Cycling Test, Anaerobic Power: The Lode cycle ergometer will be
           adjusted to the participant's body weight (7 watts per kilogram). After a warm up,
           participants will sprint cycle at maximal speed for 30 seconds. The peak power and
           average power will be recorded and adjusted to body weight.

        5. 60-Yard Shuttle Run Test: The shuttle run is a test of anaerobic speed endurance and
           agility, in which participants run to 5 yards, 10 yards, 15 yards, there and back, for a
           total of 60 yards. This is a ladder shuttle of progressing distances. Four marker cones
           are placed 5 yards apart. The participant starts from one end, runs 5 yards and back to
           the start, 10 yards and back, then 15 yards and finishes at the start line. A total of
           60 yards is completed. The participant is required to touch the line with their hand at
           each turn, and runs through the finish line, for a total of five touches. The time to
           complete the test in seconds is recorded. The score is the best time of three trials.

      Testing Sequence, Day of Eccentric Muscle Exercise (Monday) and 4-Days Recovery (Tuesday
      through Friday):

      Participants will come to the lab at 7:00 am in an overnight fasted state (i.e., no food or
      beverages other than water for at least the previous 9 hours). Participants (on Monday only)
      will provide a spot urine sample that will be aliquoted, stored in a -80°C freezer, and then
      sent to Metabolon (Durham, NC) for global metabolomics analysis (to capture metabolite shifts
      related to almond ingestion). Participants will provide a blood sample, fill in the POMS, and
      give a DOMS rating. The almond or snack supplements (half dose) will be consumed.
      Participants will perform some light exercises to warm up, followed by five muscle function
      tests (same as baseline): vertical jump, bench press, leg-back strength, 60-yard shuttle run
      test, and anaerobic power through the 30-second Wingate test. Participants will take these
      performance tests before and after the 90-minute eccentric muscle exercise bout, and each of
      the following four mornings at the performance lab.

      After taking the five performance tests, participants will engage in 90-minutes of eccentric
      exercise. This protocol induces significant muscle damage and soreness.

      Immediately following exercise, participants will provide a muscle soreness rating and a
      blood sample. Participants will then take the five muscle function tests. Participants will
      ingest the supplements (half-dose) during the afternoon. Participants will return at 7:00 am
      in an overnight fasted state four days in a row (Tuesday through Friday) after Monday's
      eccentric exercise bout, and provide muscle soreness ratings and blood samples followed by
      ingestion of the supplements (half dose). Following ingestion of the supplements,
      participants will take the five muscle function tests. Participants will the second half dose
      of the supplements in the afternoon (Tuesday, Wednesday, Thursday). On Friday morning,
      participants will take the supplement (half dose) prior to the muscle function tests. During
      this week of testing, participants will engage in normal training.

      The blood and urine samples will be analyzed for a panel of oxylipins, CRP and six cytokines,
      three muscle damage markers (creatine kinase, myoglobin, LDH), and urine metabolites.
    

Intervention name(s): Almonds; Snack bars
Intervention type(s): Dietary Supplement; Dietary Supplement
Intervention description(s): almond (Prunus dulcis) consumption; 324 calories/day, Nutri-Grain cereal bars, 120 kcal each
Allocation: Randomized
Intervention model: Parallel Assignment
Intervention model description: Randomized, parallel groups
Masking: None (Open Label)
Primary purpose: Prevention
Keywords: almonds; exercise; inflammation; oxylipins; cytokines