Knowledge about fitness goals, measuring progress, and motivation is important. Cardiovascular fitness is measured by maximum oxygen use and indicates work capacity. Functional fitness means general health and daily activity ability without discomfort. Recommendations are for moderate activity to achieve functional fitness and avoid disease. Lower intensity activity provides substantial health benefits and motivates more people. Increasing cardiovascular fitness through high intensity exercise makes a big difference by pressing the heart and lungs and making regular activities feel easier with improved fitness levels.