A strenuous workout refers to a rigorous exercise routine that requires significant physical exertion and energy. It typically involves intense activities such as running, weightlifting or high-intensity interval training (HIIT), which pushes the body to its limits in terms of strength, endurance, and cardiovascular fitness. A strenuous workout is designed to challenge the body and help individuals improve their overall physical conditioning, build muscle mass, increase stamina, and burn calories. It requires focus, determination, and discipline to complete, but can be highly effective in achieving one's fitness goals.