Research

Hormonal

Daytime wakefulness is associated with the mobilization of cytotoxic effector cells (NK cells, CTLs) to peripheral blood to provide immediate immunosurveillance against injury or infection.

Acute stress or physical activity during the day naturally mobilizes your 'first responder' immune cells (NK cells) to tissues where they are needed. This is a normal, healthy response to being awake and active.

GoodSupportsHIGH confidence
Cytotoxic effector functions prevail in the wake period... Stress leukocytes reside within the marginal pool... and are mobilised within seconds upon stimulation of their β2-adrenoceptors by epinephrine.
Luciana Besedovsky et al. · Pflügers Archiv - European Journal of Physiology · 2011

Why this rating

Supported by multiple studies cited in the review regarding stress leukocytes and catecholamine effects.

Source

Sleep and immune function

Luciana Besedovsky et al. · Pflügers Archiv - European Journal of Physiology · 2011

DOI 10.1007/s00424-011-1044-0

narrative_reviewCited 1,106×
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DOI resolved against Crossref · corpus check 2026-06-10

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