Generally speaking, there is no definite answer to the question of how long fitness will have obvious effects, because everyone's physical condition and fitness goals are different. But from the perspective of human science, the average person needs to keep fit for at least 3-6 months to see obvious physical changes. This is because human stomach cells are updated every 7 days, skin cells are updated every 28 days, and liver cells are updated every 180 days. It takes about 1 year for 98% cells in the body to be updated, and it takes a long time of 7 years for bone cells.