Physical fitness, as defined in the 1996 Surgeon General's Report on Physical Activity and Health, is the ability to carry out daily tasks with vigor and alertness, without undue fatigue and with ample energy to enjoy leisure-time pursuits and to meet unforeseen emergencies. Health officials and exercise scientists have identified several types of fitness such as muscle strength, muscle endurance, balance, speed, flexibility and aerobic or cardiorespiratory level. You can measure your level of fitness for each type you are interested. For example, leg muscle strength is usually measured as the most amount of weight you can lift at one time. Based on data from the Institute for Aerobics Research in Dallas, Texas, to have good leg muscle strength men ages 20 and 65 years should be able to press two times and 1.5 times their body weight, respectively.
Flexibility is defined as the range of motion of a joint.
Trunk flexibility is usually assessed while seated on the floor with your feet out in front of you. You would be classified as having good trunk flexibility if you are a woman between the ages of 30 and 59 years and can sit and reach three to four inches beyond your toes. Cardiorespiratory fitness is the ability of your heart to transport blood to your muscles and the ability of your muscles to use it. In contrast, patients awaiting a heart transplant generally have a level of aerobic fitness that is one-sixth that of the world class athlete. Concerning health, aerobic fitness is the most important type and carries the strongest association to the prevention of chronic diseases such as diabetes, high blood pressure, heart disease and certain cancers.