What Does Fitness Mean?
26 05 2009
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.
Flexibility of our body tissues involves all our joint and muscular structures having enough extensibility to safely perform the planned activities.
Balance is the ability of our bodies to maintain postural control in a wide variety of static and dynamic activities, enabling us to widen our ability to function.
Coordination is the ability to dynamically integrate power, endurance and balance into functionally useful movements to achieve our goals.
Health and fitness can be investigated by a variety of measurement techniques which indicate the status of particular body systems. Blood pressure measurements should be not more than one hundred and forty over ninety to be in the healthy range. The upper number indicates the aortic pressure during the ventricular pumping action known as systole (sist-oley) and the lower number indicates aortic pressure when the left ventricle is filling ready for the next pumping phase, i.e. during diastole (di-ast-oley). If the blood vessel walls are flexible they give under pressure, allowing that pressure to drop while stiffer vessel walls allow increased pressures throughout the system.
The likelihood of heart disease, the risks of stroke, problems with peripheral blood supply, abnormalities of kidney function and heart disease are all potential consequences of hypertension or high blood pressure. The risks of getting atherosclerosis or cardiac disease are increased by elevated cholesterol levels and the recommended level is less than 5 millimoles per litre. Bodyweight is another indicator of health and the BMI or Body Mass Index is a measurement of the appropriate bodyweight for our height. The typical poster gives coloured areas of the chart, relating weight to height and giving a figure which indicates the weight categories of healthy, underweight, obese or overweight.
The healthy values are given as between 20 to 24.9, so by looking at the chart we can predict what weight we should be for our height and thereby set realistic goals for our ideal size. The BMI can give results which just seem inappropriate in some people as it does not take account of the size of the body frame, the amount of muscular bulk carried and the distribution of weight. Nevertheless it remains a useful indicator of where we should be working towards. The BMI goes together with a recommended fat content for the body of between 21 and 27 percent.
