Epidemiology and Physical Activity: Impact on Health
Epidemiology: Understanding Disease Patterns
Epidemiology is the science that investigates and quantifies the various factors determining the occurrence and patterns of disease within a particular group or community. It seeks to generalize this information to a larger population to better understand, modify, or control the pattern of diseases or health problems (McArdle, Katch, & Katch, 1998). Epidemiology establishes the magnitude of a given health problem, identifies the factors causing this problem, the ways in which these factors are transmitted, and also develops a scientific basis for implementing preventive actions.
We can highlight descriptive epidemiology, whose concern is monitoring the occurrence of some diseases, correlating the data such as age, sex, ethnicity, occupation, social class, and geographical location.
Key Terms and Concepts
- DIP: Infectious and parasitic diseases
- CVD: Cardiovascular diseases
- NEO: Neoplasms
- EC: External Causes
- Nosological: Regarding nosology, which represents the study of diseases
Positive Health Behaviors
A positive attitude to health is related to healthy dietary habits, stress control, non-smoking, lower consumption of alcoholic beverages, control of body composition, and increased energy expenditure through regular physical activity.
Renowned researchers linked to the American College of Sports Medicine published a consensus on physical activity in combating cardiovascular disease. They concluded that everyone should engage in physical activities of moderate to severe intensity (60-80% of maximum heart rate) to accumulate at least 30 minutes daily, preferably all days of the week (Pate, et al., 1995).
Classic Studies on Physical Activity and Health
We cannot talk about the epidemiology of physical activity without mentioning the classic studies of Morris and Raffer, published in the early 1950s. These researchers noted the close relationship between inactivity and cardiovascular diseases through investigations with individuals in their daily work who were more or less active. They investigated two groups in the same area but of different activities, like the postman who walked and/or pedaled and colleagues of bureaucratic services. They also studied collectors who went up and down the stairs every day on two-floor London buses and their fellow drivers who passed the same time driving. The results showed that the disease was much greater among workers whose activities expended little energy.
Voluntary Energy Expenditure
Voluntary energy expenditure refers to the physical activities we conduct voluntarily beyond those necessary for our survival. Examples include walking to the bakery instead of driving, climbing the stairs instead of taking the elevator, or engaging in sports and recreational activities on weekdays.
- Kcal: A unit of energy equivalent to the amount of heat necessary to raise the temperature of one gram of water by one degree Celsius. To reduce one gram of body fat, we need to “burn” 7.7 Kcal. Thus, a voluntary expenditure of 2,000 kcal reduces about 260 grams of body fat.
- Fetal period: Intrauterine life, when we are still only a fetus in training.
- Hypoactivity: Little or no voluntary physical activity. Voluntary physical activity is that which we do far beyond the activities that are necessary.
Risk Factors for Chronic Diseases
- Hypertension
- Hypercholesterolemia
- Inadequate intake of fruit and vegetables in the daily diet
- Overweight and obesity
- Absence or lack of daily physical activity
- Consumption of tobacco
Recommendations for Physical Activity in Children and Adolescents
- Health professionals must combat the sedentary lifestyle in childhood and adolescence, encouraging physical exercise in daily life and/or in a structured way through sports, even in the presence of disease, since there are very few absolute contradictions to physical exercise.
- Professionals involved with children and adolescents who perform physical activities should prioritize its entertaining aspects over competition and avoid the practice in extreme temperatures.
- Physical education should be considered an essential and integral part of the overall education of children and adolescents (Lazzoli et al., 1998).