The Meaning of Fitness
In the springtime we all start thinking about how we could be slimmer, fitter and look better for the summer, if we haven't already taken up a gym membership in January and let it lapse fairly quickly as the first flush of enthusiasm faded. Through all this most of us do not stop and think about what fitness actually means to us. Being fit is a desired state but this state is not defined and we have little idea what all the measurements of fitness mean, all of which makes it less likely that our rather vague plan will be ultimately successful. Physiotherapists may have a somewhat clearer grasp of some of the concepts but most will not be very precise.
A major health focus in the community is the management and prevention of coronary heart disease, a very common health condition and responsible for a large annual death toll. We can all work at our risk factors and bring the various parameters closer towards safe limits. Fitness is not one thing but composed of various abilities, parts of each of which may need to be developed to reach an acceptable result. Allowing one of the components to be ignored can limit the potential fitness we might achieve.
Aerobic fitness is the ability of our bodies to maintain a level of activity for a length of time, for example to run for 20 minutes without stopping. Doing this at somewhat hard, point 13 on the Borg Exertion Scale, ensures a training effect and that we can keep the level up for a useful length of time.
For our muscles to be fit we need to develop enough strength, power and endurance in them to perform the required movements for the required time.
To achieve flexibility we need to ensure our tissues have the appropriate lengths to allow functional extensibility of our body structures.
Dynamic and functional activities demand considerable balance, maintaining the control over our postural stability as we perform complex motions under load.
To put all the previous aspects together, power, endurance, strength, balance and aerobic capacity we need to develop coordination, a dynamic control of movement.
Typical values for the measurements which are used to indicate fitness and health are a resting blood pressure of less than 140/90 (140 over 90). The higher figure, 140, is the systolic blood pressure, the pressure occurring in the main artery when the heart is in systole (sist-oley) which is the main pumping action. The lower figure, 90, is the diastolic blood pressure, the pressure in the main artery when the heart is in diastole (di-ast-oley), the resting phase when it is refilling before the next pumping action. If the diastolic, lower number is elevated it indicates that the arterial system is stiffer than it should be and so the pressure within it is higher.
From 20 to 24.9 are the recommended limits for a healthy body mass index and the chart allows the indication of a desirable weight for our size so we can plan a realistic bodyweight to aim for if we are overweight. There are some difficulties with the BMI in that some people, perhaps due to their structure or muscular bulk, seem to get unreasonable results for their predicted desirable weight. However, the body weight index does give a good indication of what a desired weight should be and can be used along with the desired body fat content of between 21 and 27%.