A tale of two pandemics: enhancing the immune system by addressing sedentary behaviors

BACKGROUND: The prognosis after a Sars-Cov-2 infection is substantially worse for individuals suffering from a non-communicable disease associated with the rampant sedentary pandemic characterized by insufficient physical activity (e.g. cardiovascular disease, obesity, diabetes). The HPA-axis, a prominent structure in aligning metabolic and inflammatory processes, is considered instrumental in this relation. METHODS: However, theoretically this provides a promising opportunity to strengthen immune functioning: reversing sedentary behaviors. A literature review was performed to investigate this hypothesis. RESULTS: Scientific evidence shows that interrupting prolonged sitting combined with moderately intensive exercise (~30 minutes every day: walking, cycling), potentially extended with 2/3 sports activities every week (~45 minutes, Heart Rate Reserve ~70%), provides an optimal exercise protocol to support immune functioning. Small but significant positive effects on immune markers are generally reported within 3 to 12 weeks. CONCLUSION: On a population scale and under pandemic conditions reducing sedentary behaviors and promoting physical exercise are likely to have a significant positive effect on the overall health prognosis.