Sports can help us a lot. Taking exercise can make us strong. In collectivesports like basketball,volleyball or football,wewill learn the importance of cooperation. And sports can also help us relax after work or study. However,as the saying goes,"There are two sides of everything. "Sometimes we may hurt other players or ourselves if we are not careful enough when participatingin sports activities. What's more,too much or hard practice can be bad for our health. Sports can make us healthy both physically and psychologically. It is also a good way for people to know each other and can improve friendship between people. So long as we are careful enough,sports can do us nothing but good. Too much exercise can be  _  for us.
good bad helpful enough