Why does the giver appear a little sad at the end of first day training?

It would be because of the pain and memories from wars and death

There are certain types of exercises that are appropriate with people who are diagnosed with cardiovascular conditions. People with these conditions need to have a regular exercise as this can help in a variety of ways, such as: losing-weight, control of blood sugar and blood pressure, and strengthening the heart muscles. But before doing such exercises, you need to consult your physician too. These exercises include: walking, swimming, light jogging, or even biking. Do not over exert and always know your limits.