The Post-Exercise "Open Window"

During and immediately after exercise, the body releases stress hormones like cortisol and adrenaline. While these help you power through a workout, they also suppress the activity of T-cells and Natural Killer (NK) cells.

In younger individuals, the immune system bounces back in hours. With age, this suppression can last longer, creating a 24 to 72-hour period where a simple virus you’d normally fight off becomes a full-blown cold.

Respiratory Focus: Exercise often involves heavy mouth-breathing, which bypasses the nose’s natural filtration and humidification system, drying out the mucosal lining of the throat and lungs and making it easier for viruses to take hold.