a stronger heart. the heart is the main organ in charge of systolic blood pressure and diastolic blood pressure. engaging in a physical activity raises blood pressure. once the subject stops the activity, the blood pressure returns to normal. the more physical activity, the easier this process becomes, resulting in a fitter cardiovascular profile. through regular physical fitness, it becomes easier to create a rise in blood pressure. this lowers the force on the arteries, and lowers the overall blood pressure. cancer prevention centers for disease control and prevention provide lifestyle guidelines for maintaining a balanced diet and engaging in physical activity to reduce the risk of disease. the wcrf/ american institute for cancer research (aicr) published a list of recommendations that reflect the evidence they have found through consistency in fitness and dietary factors that directly relate to cancer prevention. the wcrf/aicr recommendations include the following: be as lean as possible without becoming underweight. each week, adults should engage in at least 150 minutes of moderate-intensity physical activity or 75 minutes of vigorous-intensity physical activity. children should engage in at least one hour of moderate or vigorous physical activity each week. be physically active for at least thirty minutes every day. avoid sugar, and limit the consumption of energy-packed foods. balance one's diet with a variety of vegetables, grains, fruits, legumes, etc. limit sodium intake and the consumption of red meats and processed meats. limit alcoholic drinks to two for men and one for women a day. these recommendations are also widely supported by the american cancer society. the guidelines have been evaluated and individuals who have higher guideline adherence scores substantially reduce cancer risk as well as help control a multitude of chronic health problems. regular physical activity is a factor that helps reduce an individual's blood pressure and improves cholesterol levels, two key components that correlate with heart disease and type 2 diabetes. the american cancer society encourages the public to "adopt a physically active lifestyle" by meeting the criteria in a variety of physical activities such as hiking, swimming, circuit training, resistance training, lifting, etc. it is understood that cancer is not a disease that can be cured by physical fitness alone, however, because it is a multifactorial disease, physical fitness is a controllable prevention. the large associations tied with being physically fit and reduced cancer risk are enough to provide a strategy to reduce cancer risk. the american cancer society asserts different levels of activity ranging from moderate to vigorous to clarify the recommended time spent on a physical activity. these classifications of physical activity consider intentional exercise and basic activities performed on a daily basis and give the public a greater understanding of what fitness levels suffice as future disease prevention. inflammation studies have shown an association between increased physical activity and reduced inflammation. it produces both a short-term inflammatory response and a long-term anti-inflammatory effect. physical activity reduces inflammation in conjunction with or independent of changes in body weight. however, the mechanisms linking physical activity to inflammation are unknown. immune system physical activity boosts the immune system. this is dependent on the concentration of endogenous factors (such as sex hormones, metabolic hormones and growth hormones), body temperature, blood flow, hydration status and body position. physical activity has been shown to increase the levels of natural killer (nk) cells, nk t cells, macrophages, neutrophils and eosinophils, complements, cytokines, antibodies and t cytotoxic cells. however, the mechanism linking physical activity to immune system is not fully understood. weight control main article: weight control