Training, simply, is adding specific stress to the body. Your body then adapts to the stress load, and gets stronger, faster, or more powerful. There are times when completing your work out is detrimental to your training and perhaps your health. Knowing when these times are will reduce your risk of injury, and ultimately make your training more efficient and productive. •When you are sick: You may not need to stop your training with a minor cold, but if you have a more severe illness your bo.