What Does Fitness Mean?
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.
Heart health is a major focus of becoming fit as coronary heart disease is a one of the most prevalent conditions in society and one of its greatest causes of death. It is useful for all of us to pay attention to our coronary risk factors and strive to bring them to within normal limits. Fitness involves a series of different components, all of which need to be worked on if the overall result is to be best. Neglecting any one of the factors can prevent us from developing our greatest fitness potential.
To achieve aerobic fitness we need to choose an overall body activity and maintain the performance at a particular level for a particular time. e.g. swim for 30 minutes. The degree of difficulty needs to be such to engage a training effect so we must be able to continue the activity for long enough.
To achieve muscular fitness we need to acquire sufficient strength and endurance in our muscles to achieve the forces and duration needed.
Flexibility of our body tissues involves all our joint and muscular structures having enough extensibility to safely perform the planned activities.
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.
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.
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%.
