High-volume endurance athletes face the "open window" phenomenon — a period of 3–72 hours post-exercise during which immune function is suppressed and infection susceptibility increases. Lactoferrin's NK cell activation and mucosal IgA promotion directly addresses this vulnerability, while its LfR1-mediated iron absorption specifically benefits the 15–35% of female endurance athletes who develop iron deficiency anemia.

Should athletes take lactoferrin before or after training?

The timing relative to training doesn't matter significantly. Consistent daily dosing (fasted, before first meal) is more important than training-synchronized timing. The benefits (immune function, iron absorption) are chronic effects built over weeks.

Can lactoferrin replace iron supplements in iron-deficient athletes?

For mild iron deficiency (ferritin 15–30 ng/mL), lactoferrin may be sufficient as the primary intervention. For moderate-to-severe deficiency (ferritin <15 ng/mL, hemoglobin declining), higher-dose iron supplementation alongside lactoferrin may be needed — discuss with your physician.