The sandbag has been tied for a long time, which must have an effect. You have to untie it for about 30 minutes, otherwise it will lead to blood vessel blockage. Generally speaking, running for fitness should not be less than 65,438+00 minutes, and running for weight loss should not be less than 20 minutes. Immunity will be suppressed if you run too much. Strength training mainly considers endurance, and running is not necessarily the best project, because the physical load is too heavy and it is easy to cause joint damage.