The term "in shape" is often used to suggest that something or someone is in a positive overall condition.
If a person is overweight and eventually loses a few pounds or kilograms. That person might say that he’s in better shape or good shape.
如果某人體重過重，經過一段時間後減重，那他現在身體處於 "better shape or good shape" 較佳或健康狀況。
If you can perform the sport well, you are considered in shape.