In particular, individuals with type 2 diabetes have been shown to benefit from exercise, as it can improve their immune function [109], lung function [110], the level of anti-inflammatory cytokines such as IL-4, IL-10 and lipocalin, and health-related quality of life [111,112], while reducing levels of inflammatory factors (TNF-α, IL-1β, and IL-6) and the emotional burden [111,113], thus maintaining a relatively good physical condition and a controlled glycemic status and, ultimately, protecting against COVID-19 virus invasion. Here, TNF is linked to type 2 diabetes mellitus.