Muscular health has been shown to improve body composition, metabolic health, and longevity by decreasing the risk for cardiovascular, musculoskeletal, and metabolic diseases. It can improve health outcomes by balancing the distribution of forces within a joint, increasing basal metabolic rate and bone density, reducing body fat and cardiovascular risk factors, enhancing endothelial function, and promoting cognitive function and psychological well-being. Physical activity can be an effective way to improve muscle tone; however, an intense exercise routine may be associated with delayed onset muscle soreness (DOMS) lasting several days and manifesting as muscle pain, stiffness, and reduced function, which can negatively impact athletic recovery and performance.
Two recent clinical studies examined the effect of an innovative ingredient, NPN_1 (PeptiStrongTM), on muscle health and DOMS. NPN_1 is a natural peptide network derived from the fava bean (Vicia faba), using a predictive machine learning approach to identify the bioactive peptides with optimal properties, supporting healthy inflammatory responses and protein synthesis. The first controlled study (n = 30) found that males (30 to 45 years old) supplemented with 2.4 g per day of these bioactive fava bean peptides showed improved muscle strength recovery and muscle synthesis and reduced muscle fatigue as compared to a control placebo group. The second clinical study (n = 30) compared the effectiveness of the plant-derived NPN_1 to that of a high-quality animal-derived protein reference, milk protein concentrate (MPC), in terms of modulating muscle loss during periods of immobilization and improving protein synthesis during remobilization. This study found that males (19 to 29 years old) supplemented with 10 g of the fava bean peptides twice daily showed similar muscle recovery results to the group that was supplemented with MCP.
Muscle strength recovery
In the first randomized double-blind placebo-controlled trial (n = 30), initial muscle strength was measured at baseline in terms of peak torque per body weight (PTBW), which is the ratio of the maximum torque produced to an individual’s body weight. Participants were then supplemented with either a placebo or 2.4 g per day of PeptiStrongTM for 14 days, after which DOMS was induced using intense resistance exercise. Muscle strength recovery, as PTBW, was measured at 48 and 72 hours post-DOMS induction. In the control group, muscle strength decreased significantly from baseline at 48 hours and did not return to baseline at 72 hours. In contrast, athletes supplemented with the fava bean peptide NPN_1 maintained their muscle strength with no significant reduction at 48 hours and they showed a significant increase from baseline at 72 hours, suggesting a significantly improved muscle strength recovery in the PeptiStrongTM group.
In the second randomized trial (n = 30), young men were subjected to a single-legged knee immobilization using a cast for 7 days, followed by 14 days of recovery. Participants were randomly allocated into two equal groups and supplemented, twice daily, with either 10 g of the fava bean peptides (NPN_1 group) or a milk protein concentrate with a comparable protein level (MPC group). Muscle strength was measured as one-legged knee extension and leg press strength using one-repetition maximum (1RM), which refers to the maximum amount of weight an individual can lift for one repetition of a given exercise using proper technique. Muscle size was also measured using tomography scans to assess the cross-sectional area (CSA) of the quadriceps. The results showed that both groups experienced similar muscle size loss and muscle strength decrease during immobilization and similar muscle size regain and strength recovery after remobilization. This suggests that individuals supplemented with the fava bean peptides NPN_1 experienced similar muscle mass and strength recovery as those supplemented with the milk protein concentrate.
Muscle fatigue, endurance, and performance recovery
Muscle fatigue is one of the key hindrances to athletic performance associated with DOMS. The fatigue index (FI) was calculated by measuring the difference between the highest and lowest recorded muscle strength. There were no differences observed in FI at baseline between the two groups. However, athletes supplemented with PeptiStrongTM showed significantly lower fatigue, significant performance benefit, and improved muscular endurance at 72 hours after the strenuous exercise, compared to the control group.
Skeletal muscle protein synthesis and regeneration
In addition to muscle strength recovery and performance metrics, subjects supplemented with PeptiStrongTM also displayed moderated myokine activity. Myokines are cytokines released by muscles during contractions and can be indicative of muscle tissue injury. Blood samples were collected at baseline and subsequently at 0, 2, 48, and 72 hours post-DOMS induction and a myokine array was used to analyze 14 myokines. The results indicated that several myokines were modulated immediately after DOMS induction in the group supplemented with PeptiStrongTM. In particular, there was an increase in irisin expression, which can be associated with glycogen replenishment, and an increase in interleukin(IL)‐15, which may support muscle mass regeneration and myoblast differentiation. Furthermore, the PeptiStrongTM group exhibited suppressed release of myostatin, a myokine that inhibits muscle growth, thus supporting muscle protein synthesis. Finally, the experimental group also had significantly increased fractalkine and osteonectin levels compared to the control group, which may further promote muscle regeneration and protein synthesis.
Furthermore, individuals supplemented with the fava bean peptide network NPN_1 showed increased myofibrillar protein synthesis (MPS) rates. MPS is a metabolic process that incorporates certain proteins into skeletal muscle after resistance training, supporting muscle mass increase. During immobilization, MPS rates were similar between the NPN_1 and MPC groups, suggesting that the two types of supplementation are comparable in terms of preserving muscle mass in periods of immobilization. During remobilization, however, the MPS rates were greater in the group supplemented with NPN_1 than in the MPC group.
Improved muscle strength recovery, fatigue recovery, and muscle regeneration can help support overall muscular health and protect muscles after strenuous exercise. Even though further research in this field is needed, the cumulative results of the clinical studies described above suggest a potential for PeptiStrongTM to reduce the severity of DOMS, allowing a faster return to training, and to support healthy skeletal muscle growth and retention, endurance capacity, and overall muscular health.
Learn more about muscle health:
Muscle Tone Matters: The Key to Optimal Body Composition and Metabolic Health
Collagen Peptides to Promote Skeletal Muscle
Beyond Protein: Nutrition for Muscle Health
By Antonia Toupet, PhD
Designs for Health has been dedicated to being the most trusted source for superior quality, science-based nutritional products for nearly three decades. We’re committed to maximizing successful health outcomes by providing healthcare practitioners with comprehensive support through our extensive product line, ongoing clinical education, and practice development programs. The blogs we publish here cover a range of topics, including new and original approaches to diet and healthcare, analyses of the latest cutting-edge research, deep-dives into specific nutrients, botanicals, nutraceuticals and more, all fully referenced for those who want to dig deeper into the primary literature.
