Associations between Physical Activity and Liver Cancer Risks and Mortality: A Systematic Review and Meta-Analysis

(1) Background: The purpose of this meta-analysis was to investigate associations between physical activity (PA) and risks and mortality of liver cancer (LC) to suggest a minimum physical activity threshold to reduce LC risks and morality. (2) Methods: A database search was performed to identify relevant studies on the associations between PA and risks and mortality of LC before August 2020. The PA amounts were divided into three groups (high: ≥3 h/week, moderate: 2-3 h/week, and low: <2 h/week). The pooled relative risks of LC were calculated. (3) Results: A total of 10 prospective cohort studies were included. LC risks and mortality were 26% and 25% lower with high amounts of PA and 23% and 19% lower in moderate amounts of PA, respectively, compared to low amounts of PA. At the vigorous intensity PA level, high and moderate amounts of PA reduced the LC risk by 54% and 45%, respectively. (4) Conclusions: PA helps to reduce LC risks and mortality in a dose-dependent manner. At a minimum, two hours/week PA are mandatory to reduce LC mortality.