Final answer:
Stopping an exercise routine during pregnancy is recommended if a pregnant woman experiences dizziness, severe headaches, or excessive fatigue, as these may indicate potential underlying health concerns.
Step-by-step explanation:
Reasons for stopping an exercise routine for a pregnant woman include dizziness, severe headaches, and excessive fatigue. These symptoms can be a sign of underlying issues that could jeopardize the health of the mother or fetus. For instance, breathlessness and giddiness may indicate a lack of oxygen or low blood pressure, while severe headaches could be a sign of preeclampsia, which is a serious condition requiring medical attention. It is also common for pregnant women to experience an increase in fatigue due to the extra energy demands of supporting a growing fetus. All of these symptoms also tie back to changes in the respiratory and cardiovascular systems to meet the increased metabolic demands during pregnancy. When any of these occur, it is prudent to cease exercising and consult a healthcare provider.