The benefits and risks of exercise, along with the importance of pre-screening for a subject with specific health conditions
...vels of cholesterol and how exercise changes levels of both LDL and HDL in the body. The general arguments are that total cholesterol and LDL are decreased following an exercise training program and that HDL levels actually increase. As Mcardle, Katch & Katch (1996) explain that low levels of LDL and high levels of HDL decrease the risk of coronary heart disease both these adaptations are deemed advantageous to the patients. Kokkinos & Fernhall (1999) examined physical activity and HDL cholesterol levels and found that there was a favourable increase in HDL levels after aerobic exercise training had been carried out. This conclusion comes from a review of numerous epidemiological studies of which most support the statement. Also an independent study that was conducted using 2906 middle-aged men, which is a relatively large number of subjects increasing the reliability of the evidence, but the health condition of the subjects was not made clear and may not have been necessarily suffering from hypercholesterolaemia. A study focusing on LDL levels in response to exercise by Vasankari et al. (1998) showed that the 34 men with mean age of 43.6 yrs and a mean body mass index (BMI) of 29.6 decreased their levels of LDL cholesterol by an average of 10%. Although the mean subject details were similar to those of the client the ranges (34-52 yrs and 24-44 BMI) showed a large variation within the subjects used. So out of the relatively small sample of 34 it was possible that very few of them had similar characteristics to the client, which means the conclusions are not as relevant as first thought. Rauramaa & Leon (1996) reported on the effect of physical activity on the risk of cardiovascular disease and stated that hypercholesterolaemia was one of the traditional risk factors of the disease. The findings showed a rise of up to 15% in HDL levels through regular physical activity. However this statement must be interpreted with caution as no information was given about the subjects used and the exercise details, therefore it is more of a general statement to support other more specific evidence. A meta analysis of 27 longitudinal studies by Lokey & Tran (1989; cited by Shephard 1997) summarised that total cholesterol did decrease with exercise training, but also found that if the data was statistically adjusted for changes in body mass then there was no extra affect of exercise. This idea is supported by Kohrt, Obert & Holloszy (1992; cited by Shephard 1997) who linked improvements in lipid profile to changes in body composition. These studies lean toward the conclusion that cholesterol levels are directly linked to body composition and therefore indirectly linked to exercise, if exercise is assumed to favourably enhance body composition. This assumption is backed up by Pacy, Webster & Garrow (1986) as they conclude that regular undertaking of physical activity may by helpful in promoting weight loss, fitness and a feeling of well-being. However earlier in their report it is stated that exercise should be accompanied by reduce calorific intake to be effective. This and the Meta analysis mentioned previous bring doubt into the aforementioned benefits of exercise on hypercholesterolaemia. However there is still overwhelming evidence supporting exercise as an intervention of the condition (Kokkinos & Fernhall 1999; Rauramaa & Leon 1996; U.S Department of Health and Human Services 1998; Vasankari et al 1998; Wannamethee & Shaper 2001). Further research into exercise, body composition and cholesterol may help to give a more definite conclusion. Risks of Exercise Risks of exercise are apparent for all participants taking part in any type of exercise. A comprehensive list of the risks is given by the U.S. Department of Health and Human Sciences (1998) and they include; musculoskeletal injuries, metabolic abnormalities, hemalogic & body organ abnormalities, activity hazards, infections, allergic & inflammation conditions, and cardiac events. The department conclude by stating that the chance of incidence of each risk depends on subject characteristics and exercise details, which is sensible to assume as the risks of participation in walking for someone who is fit and healthy would be far less than for someone participating in cross country skiing who is obese and has asthma. The main risks of exercise for adult hypertensive patients identified by Gordon et al (1990) are orthopaedic injury and sudden cardiac death. These risks are again mentioned by Mittleman et al (1993) & also by Willich et al (1993), both reports cited by Hardman (1996). This volume of supporting evidence helps to increase the strength of the findings. In relation to hypercholesterolaemia, cardiac and cardiovascular complications seem to be most prevalent in the research (Hardman 1996; Kokkinos & Fernhall 1999; Wannamethee & Shaper 2001). Again numerous citations help to increase the validity of this notion. Also the reports that mentioned these risks were mainly reviews of several epidemiological studies, which means that a lot of research has been done over an extended period of time. This suggests the summarised statements have reasonable evidence for their accuracy. In all the studies suggesting risks they are reported to be higher for participants of high intensity exercise due to the increased demand and stress on the cardiovascular and musculoskeletal systems. This would obviously be the case as the client’s conditions are both physiological detriments to the capacity of the bodies systems i.e. decreased capacity causes decrease in ability to cope with demand. The risks of resistance or strength training for someone with hypertension have been well documented and a clear conclusion is not apparent. The American College of Sports Medicine (2000) mentioned its benefits, but only for selected patients and Rauramaa and Leon (1996) recommended this mode with prior medical clearance. These statements, with an obvious cautious element, lead to the conclusion that there must be some serious risks involved. Gordon et al (1990) identified the risk of excess demand on the myocardium, which has traditionally discouraged the use of resistance training. However the review of several studies resulted in little evidence to support these apparent risks. Although there are risks involved with exercise it is very important to recognise that the health risks associated with participation are lower than the health risks induced by an inactive lifestyle (Howley & Franks 1997). This statement is only valid if the exercise is performed under the appropriate conditions for the participant, which become increasingly more important when dealing with patients of serious health conditions. Pre-screening Prior to the adoption of any form of exercise programme, the client should obtain medical clearance via pre-screening (ACSM, 2000). Pre-screening is not only necessary to detect any medical conditions, alongside the characteristics that may increase the risk of such conditions, but also identify symptoms and lifestyle behaviours related to any health problems (Howley and Franks, 1997). It is essential for the client to undertake a medical evaluation that includes a maximal graded exercise test, with electrocardiographic monitoring, prior to any exercise (Gordon et al. 1990). As well as identifying the extent of the clients’s condition and capabilities, such as the modes, frequencies, intensities and durations that the client can perform, the medical evaluation would establish the client’s O2 max and maximum heart rate (Howley and Franks, 1997). Both of which can be used for exercise intensity monitoring (McArdle et al., 2001). Furthermore, it should be emphasised that pre-screening is not a ‘one-off’ process. Not only should pre-screening take place prior to the adoption of an exercise program, it is also necessary 2-3 months into training and then once every year (ACSM, 2000). Future medical evaluations are required to both re-assess the medical problem and identify any beneficial adaptations of exercise (Wasserman et al., 1999). Therefore this re-evaluation can be used as a measure of success for the training regime. The findings from each of these categories provide important information on the capacity of the subject to perform exercise. Including what modes, frequencies, intensities and durations that the subject will able to perform and which they will be of benefit from most. Wasserman et al (1999) identified the use of non-invasive cardiopulmonary testing during exercise as the most sensitive and effective form of screening during exercise, stating that this technique is ideal for the screening and monitoring cardiovascular diseases. This could be useful during a pre-exercise medical evaluation for the client although this study did not focus directly on the conditions of the client in question, and admitted there was little research related to the technique. . indicative of health problems, identify lifestyle behaviours related to health problems, and finally establish fitness measures from test results ensure participant safety during exercise, alongside establishing the appropriate exercise recommendations needed to induce the modifications required. It is essential in the client’s situation to perform a medical evaluation that includes a maximal graded exercise test, with electrocardiographic monitoring before any exercise takes place (Gordon et al. 1990). As well as identifying the extent of the clients’s condition and capabilities, the medical evaluation would establish the client’s O2 max and maximum heart rate. Both of which can be used for exercise intensity monitoring (McArdle et al., 2001) Participant safety is an important issue in any form of exercise prescription for any type of person. Obviously if someone has specific medical conditions and particular goals to achieve this process becomes increasingly more complex. It is essential in the client’s situation to perform a medical evaluation that includes a maximal graded exercise test, with electrocardiographic monitoring before any exercise takes place (Gordon et al. 1990). As well as identifying the extent of the subject’s conditions and capabilities this process provides 2 important values, the subjects VO2max and their maximum heart rate. Both of which can be used for exercise intensity monitoring. Howley & Franks (1997) agree with this by stating all participants over 40 should complete a maximal graded test with qualified physician present. They also outline the reasons for a medical evaluation, which are; detection of medical problems, detection of characteristics that might increase risk of medical problems, identifying symptoms indicative of heath problems, identifying lifestyle behaviours related to health problems, and finally to record fitness measures from test results. The findings from each of these categories provide important information on the capacity of the subject to perform exercise. Including what modes, frequencies, intensities and durations that the subject will able to perform and which they will be of benefit from most. Wasserman et al (1999) identified the use of non-invasive ...