First of all, taking a cold bath will shrink the pores of the skin, which may lead to overheating during exercise, such as sweating and fatigue. In addition, cold water may stimulate the body's immune system, making the body spend more resources in the heating process instead of exercising.

Secondly, cold water may lower the temperature of muscles and weaken their strength and endurance. This may affect the efficiency and effectiveness of exercise.

Generally speaking, if you plan to do strenuous exercise, you'd better wait for a while after taking a cold shower to adjust your body to a state suitable for exercise. Everyone's physical condition and exercise adaptability are different, so it is recommended to consult a doctor or professional fitness coach before trying this exercise.