Stamina is your ability to endure and keep going both mentally and physically, will-power and fitness.
Shortness of breath and sweating even after relatively short and easy movement is lack of stamina, and so is frustration. As you develop your stamina you will feel you have more energy and everything that you do will seem much easier than it used to be. Because of your improved efficiency you will be able to do more at a higher tempo for the same amount of energy. Walking five to ten flights of stairs will seem both natural and easy. Stamina in its essence is about conservation of energy.
At Playing for Life stamina is a natural consequence from the activity and conditioning that we do.