Objective: This study answers the question: Are there differences in the level of physical activity of Chilean women before and during the COVID-19 lockdown? Method: The study has a non experimental longitudinal trend design with n = 1,051 young Chilean women. Differences in the level of physical activity between the pre (preCOVID) and post (COVID-19) groups were measured and, in the case of the COVID-19 sample, contrasted with theoretical data from both previous physical activity studies and national government questionnaires. Results: the women of the COVID-19 group present lower levels of physical activity than the women of the preCOVID sample as well as vis-à-vis the samples of women from previous empirical studies. Conclusion: in times of COVID-19, young Chilean women present a lower level of physical activity than in previous times without lockdown due to the pandemic.