accelerates stem cell recruitment to human skeletal muscle after exercise.

is a parasitic fungus known to induce immune responses. The impact of supplementation on stem cell homing and expansion to human skeletal muscle after exercise remains unexplored. In this study, we examined how pre-exercise supplementation influences cell infiltration, CD34 cell recruitment, and Pax7 cell expansion in human skeletal muscle after high-intensity interval exercise (HIIE) on a cycloergometer. A randomized, double-blind, placebo-controlled crossover study was conducted with 14 young adults (age: 24 ± 0.8 years). A placebo (1 g cornstarch) and (1 g ) were administered before exercise (at 120% maximal aerobic power). Multiple biopsies were taken from the vastus lateralis for muscle tissue analysis before and after HIIE. This exercise regimen doubled the VEGF mRNA in the muscle at 3 h post-exercise ( = 0.006). A significant necrotic cell infiltration (+284%, = 0.05) was observed 3 h after HIIE and resolved within 24 h. This response was substantially attenuated by supplementation. Moreover, we observed increases in CD34 cells at 24 h post-exercise, notably accelerated by supplementation to 3 h (+51%, = 0.002). This earlier response contributed to a four-fold expansion in Pax7 cell count, as demonstrated by immunofluorescence double staining (CD34/Pax7) ( = 0.01). In conclusion, our results provide the first human evidence demonstrating the accelerated resolution of exercise-induced muscle damage by supplementation. This effect is associated with earlier stem cell recruitment into the damaged sites for muscle regeneration.