Polyphenol power: grape & apple extract may boost exercise in thin air

This study tests whether a supplement called Vinitrox™, made from grape and apple polyphenols, can improve blood vessel function and exercise performance in healthy adults during moderate exercise in low-oxygen (hypoxic) conditions. 38 physically active volunteers will take either the supplement or a placebo before an exercise session. Researchers will measure blood vessel dilation, oxygen levels, and exercise output to see if the supplement provides any benefit.