Physical fitness generally refers to your ability to perform daily physical activities without risking injury or illness. It also refers to an athlete's ability to perform at high levels without injury or illness. These qualities include cardiorespiratory strength and stamina, muscular strength and endurance, flexibility, the ability to recover from physical activity and attributes such as speed, balance, quickness and agility.
A key component of physical fitness is heart health. The stronger your heart, the more physical activity you can perform at one time. A stronger heart helps pump more blood to your muscles, providing oxygen and nutrients. Cardio stamina helps you perform activities over time at different levels of intensity. Good heart health helps you reduce your risk for heart attack and stroke. In addition to exercise, diet can help improve heart health by decreasing nutrients such as saturated fat, cholesterol and sodium, too much of which can lead to health problems.
The more muscular strength you have, the more physical activity you can perform at one time, such as lifting a heavy box or weight. The longer you can use your muscles, the more muscular endurance you have. Developing power helps you make quick, explosive movements, such as starting a race or hitting a ball. Athlete's improve their fitness by working on the footwork, balance, speed, agility and quickness.
Being able to stretch your muscles helps you perform movements with more speed and power, and makes daily activities more comfortable. As you age, you tend to use your muscles less, and it can become difficult for seniors to get in and out of cars and beds and on and off sofas and chairs. Physically fit people maintain their flexibility with regular stretching.
Physically fit people maintain a healthy weight, with higher proportions of their body mass coming from lean muscle than fat. When enough of your body mass comes from fat, you become obese, which leads not only to poor physical performance, but also increases your risk for heart attack, stroke, diabetes, back and joint pain and psychological problems. In addition to exercise, a healthy diet is key to maintaining a physically fit body.
If you need long periods to recover from a walk, bike ride, sports or physical activity at work or around the house, you'll need to improve your ability to recover from exertion. This can include regular exercise, several times each week, and stretching. Athletes often perform interval training, which occurs in short, high-intensity bursts of activity, followed by a slower recovery period. This helps the muscles, heart and lungs recover over and over again, training them to remove chemicals such as lactic acid from muscle tissue, and replenish chemicals that help move your muscles. Regular moderate or vigorous exercise keeps your cardio and muscular systems used to physical activity, making it easier to recover from exertion.