Almond consumption modestly improves pain ratings, muscle force production, and biochemical markers of muscle damage following downhill running in mildly overweight, middle-aged adults: a randomized, crossover trial.1
“ "Our study provides more insight into the role almonds may play in supporting fitness recovery. Almonds contain a wide range of nutrients that we know support exercise recovery including protein, antioxidants and phytonutrients. These nutrients are supplied in a whole food package versus isolated vitamin supplements which may contribute to the almond benefits observed in this study.""
Dr. Mark Kern, PhD, RD, CSSD, professor of exercise and nutritional sciences at San Diego State University.
Study participants:
This randomized, crossover study1, published in Current Developments in Nutrition included 26 middle-aged adults who exercised one to four hours per week and were at a healthy weight or mildly overweight (body mass index (BMI) of 23-30). Participants ate either two ounces (57g) of whole raw almonds or a calorie-matched (three ounces / 86g) of unsalted pretzels daily for eight weeks.
Study design:
After eight weeks of eating almonds or the control food with a four-week washout period between the two interventions, participants performed a 30-minute downhill treadmill run to induce muscle damage, then were immediately given their daily two-ounce (57g) serving of almonds or calorie-matched pretzels. Participants continued to eat daily servings of almonds or pretzels for three days after the treadmill run.
Researchers measured participants’ perceived muscle soreness, muscle performance (assessed via a muscle contraction test and a vertical jump) and blood markers of muscle damage/inflammation (creatine kinase, C-reactive protein, myoglobin and antioxidant capacity) before the treadmill run and at 24, 48 and 72 hours after the run.
Study results:
During exercise recovery (up to 72 hours after the treadmill run), the almond group compared to control had:
- Lower creatine kinase (CK) levels - a marker of muscle damage.
- A quicker decline in CK levels after 72 hours, which may indicate a faster recovery rate.
- Better muscle performance at 24 and 72 hours.
- Modestly reduced pain ratings following maximal contraction at 24 (37% lower) and 48 hours (33% lower).
There were no differences in other biochemical markers of muscle damage and inflammation (like C-reactive protein, myoglobin concentrations and total antioxidant capacity). For both trial groups, CK levels did not return to baseline.
Study limitations:
This study evaluated non-smoking adults who exercised one to four hours per week and were at a healthy weight or were mildly overweight, so the results may not apply to people with other demographic and health characteristics. Future studies should also consider taking measurements over a longer recovery period.
Study conclusion:
Snacking on two ounces (57g) of almonds for eight weeks modestly reduced pain ratings, helped maintain muscle strength, and reduced muscle damage after exercise.