The intensity in which you exercise will have a significant impact on the effectiveness of your workout towards your fitness goals and it is important to be aware of and work within these boundaries to get the most from your exercise programme. You should alternate between intensity zones to improve fitness and vary your exercise. There are a few standard ways to determine your training zones; one based upon Heart Rates and another upon your perception of intensity (Ratings of Perceived Exertion).
Your heart rate increases as the intensity of your exercise increase so to start, you need to calculate your maximum heart rate, which is the maximum heart rate your body could cope with. The simplest (but not the most accurate) method of doing this is as follows:
220-your age=maximum heart rate
Following this, heart rate training zones are based upon a percentage of your maximum heart rate:
Light Intensity 50-60% training at this level will improve general stamina and endurance levels. It is also the intensity at which fat is most likely to be utilised for energy.
Moderate Intensity 60-70% to improve cardiovascular fitness and endurance you need to be working at 60-70% of your maximum heart rate. If you exercise regularly, you ought to be training within these heart rates and aim to maintain this level whilst feeling comfortable and pain-free.
High-intensity training 70-80% exercising in this level will cause you to breathe heavily, and have muscle fatigue, thus, you won’t be able to maintain this intensity for long periods and should have interludes of lower intensity exercise.
Ratings of perceived exertion is a method based upon the physical sensations you experience during physical activity, such as increased heart rate and breathing rate, increased sweating, and muscle fatigue. Although it is a subjective measure, it has been shown to correlate with heart rates during exertion and is ideal if you have no method of measuring your heart rate. The ratings range from 6-20, 6 being no exertion to maximal exertion at 20. It is suggested that perceived exertion rates of 12-14 are equivalent to moderate intensity activities. Ratings of 10-11, are equivalent to light intensity and exertion above 15 is classed as high intensity.
Self-monitoring how hard your body is working can help you adjust the intensity of the activity by speeding up or slowing down your movements.
Further Reading is available at www.nhs.uk/livewell/fitness/pages/Fitnesshome.aspx