Exercise as it relates to Disease/Exercise Guidelines for Reducing Risk of Cardiovascular Disease

Cardiovascular disease (CVD) refers to a class of diseases that impact on the normal functioning of the heart and/or blood vessels. CVD is comprised of many diseases including;

• Ischaemic heart disease.
• Stroke.
• Coronary heart disease.
• Myocardial infarction.
• Hypertension.
• Rheumatic heart disease¹.

CVD is the leading cause of death within Australia, resulting in 32% of deaths nationally during 2007-2008 with the majority of these deaths a result of Ischaemic heart disease and stroke. 3.5 million Australians are currently living with one or more CVD conditions and prevalence increases significantly with increasing age. 19% of 45-54 year olds compared to 62% of 75+ years old are currently living with CVD¹.

Non-modifiable risk factors such as age and family history are strong predictors of CVD. Modifiable risk factors include; smoking, physical inactivity, poor diet and obesity².

Physical Activity and Cardiovascular Disease

Increasing physical activity and decreasing sedentary behaviour will reduce a individual's risk of Cardiovascular disease. A combination of aerobic and resistance training completed with moderate intensity will assist in:

• Decreasing fat mass.
• Increased cardiovascular adaptations.
• Increased strength and functional capacity.
• Increased quality of life.
• Greater prospect of exercise program adherence³.

Sedentary Behaviour

Increased sedentary behaviour has been shown to increase CVD mortality risk, with a strong association between time spent sitting and mortality. The highest mortality rate is demonstrated in sedentary individuals who are also obese. Decreased glucose tolerance, alterations to lipo-protein lipase activity and cardiac changes are related to an increased CVD mortality rate resulting from sedentary behaviour⁴.

Aerobic Training

Aerobic training can lead to adaptations within the cardiovascular system that help protect itself from CVD. Aerobic exercise decreases body fat, decreases plasma triglycerides and increases cardiac output. Aerobic training adaptations are highly beneficial for decreasing CVD risk and reversing known risk factors such obesity and high blood pressure⁵.

Resistance Training

Resistance training develops strength, endurance and physical capacity. These benefits are very important in older populations as it allows maintenance of independence, decreased disability and a greater quality of life. Resistance training also adds variety to an exercise program which can help facilitate adherence⁶. Resistance training has been indicated to be safe for all populations if correct loads, exercise selection and techniques are used. Light loads and utilising machines are encouraged in the initial stages of the exercise program to allow development of basic strength and technical understanding of movements^2,6.

Potential Complications

Extremely vigorous exercise without prior experience can be detrimental to cardiovascular health in individuals with moderate to high risk levels. Myocardial infarction may be induced due to immense cardiovascular stress^3,7.

Resistance training with heavy loads also increases blood pressure and stresses the cardiovascular system. Correct breathing and lifting techniques assist in minimising blood pressure increases during resistance training⁸.

Physical Activity Recommendations

Medical advice should be obtained from a GP prior to commencement of a physical activity regime. Medical screening can determine a individual's CVD risk and the appropriate level of physical activity intensity. Medical clearance should then be passed on to the supervising fitness professional.

Training should be predominantly aerobic based to maximise cardiovascular adaptations with an additional resistance training component for strength and functional capacity development. Programs should be tailored to individual needs based on age, current fitness level and risk factors.

Aerobic training

Frequency	3-5 sessions per week.
Intensity	Moderate intensity activities.
Time	Aim for 30 minutes or more each day (can be completed throughout the day).
Type	Brisk walking ideal for initial training before moving on to moderate intensity activities such as jogging. Non-weight bearing exercises such as swimming and cycling for obese.

Resistance training

Frequency	1-2 sessions per week.
Intensity	1-2 sets, 10+ repetitions, 8-12 exercises per session. Load of around 40% 1RM.
Time	30–45 minutes per session.
Type	Alternate upper body and lower body exercises to minimise fatigue ensuring appropriate movement and breathing techniques are used.

Individuals at higher risk should be supervised by a fitness professional and sessions should not be undertaken alone. Medications should be continued and the supervising fitness professional should be aware of current medication use. Training in extremely hot conditions should also be avoided.

Training should be ceased immediately if the individual feels shortness of breath, light-headedness, chest pain, chest tightness or an irregular heartbeat.

Further Information

The Heart Foundation

http://www.heartfoundation.org.au

Australian Absolute Cardiovascular Disease Risk Calculator

http://www.cvdcheck.org.au/

References

^1.ABS. 2010. Causes of Death [Online]. Canberra. Available: http://www.abs.gov.au/ausstats/abs@.nsf/mf/3303.0/ [Accessed]

^2.PEARSON, T., BLAIR, S., DANIELS, S., ECKEL, R., FAIR, J., FORTMANN, S., GOLDSTEIN, L., GREENLAND, P., GRUNDY, S., HONG, Y., MILLER, N., LAUER, R., OCKENE, I., SACCO, R., SMITH, S., STONE, N. & TAUBERT, K. 2002. AHA Guideline for Primary Prevention of Cardiovascular Disease and Stroke: 2002 Update: Consensus Panel Guide to Comprehensive Risk Reduction for Adult Patients Without Coronary or Other Atherosclerotic Vascular Diseases. . Circulation: Journal of the American Hear Association, 106.

^3.THOMPSON, P., BUCHNER, D., PINA, I., BLADY, G., WILLIAM, M., MARCUS, B., BERRA, K., BLAIE, S., COSTA, F., RODRIGUEZ, B., YANCEY, A. & WENGER, N. 2003. Exercise and Physical Activity in the Prevention and Treatment of Atherosclerotic Cardiovascular Disease. Arterioscleriosis, Thrombosis, and Vascular Biology, 23, 42-49.

^4.KATZMARZYK, P., CHURCH, T., CRAIG, C. & BOUCHARD, C. 2009. Sitting Time and Mortality from All Causes, Cardiovascular Disease, and Cancer. . Medicine & Science in Sports and Exercise. 41, 998-1005.

^5. KELLEY, G., KELLEY, K. & FRANKLIN, B. 2006. Aerobic Exercise and Lipids and Lipoproteins in Patients With Cardiovascular Disease: A Meta-Analysis of Randomized Controlled Trials. Journal of Cardiopulmonary Rehabilitation, 26, 131-144.

^6. WILLIAMS, M., ADES, P., AMSTERDAM, E., BITTNEM, V., FRANKLIN, B., GULANICK, M., LAING, S. & STEWART, K. 2007. Resistance Exercise in Individuals With and Without Cardiovascular Disease: 2007 Update. Circulation: Journal of the American Hear Association., 117, 572-584.

^7. FRANKLIN, B., BALADY, G., BERRA, K., GORDON, N. & POLLOCK, M. 2012. Exercise for persons with cardiovascular disease. [Online]. Available: http://www.acsm.org/docs/current-comments/exercise-for-persons-with-cardiovascular-disease.pdf [Accessed]

^8.POLLOCK, M., FRANKLIN, B., BALADY, G., CHAITMAN, B., FLEG, J., FLETCHER, B., LIMACHER, M., PINA, I., STEIN, R., WILLIAMS, M. & BAZZARRE, T. 2000. Resistance Exercise in Individuals With and Without Cardiovascular Disease. Circulation: Journal of the American Heart Association., 101, 828-833.