Daily physical activity supports a healthy lifestyle. Experts recommend at least 30 minutes of moderate intensity exercise per day for optimum health benefits. Activities such as brisk walking, cycling or walking around the mall in minimum increments of 10 minutes count toward fulfilling those guidelines. Cardio activities, performed properly, should increase your heart rate and breathing intensity for an extended time period.
Function
By using the large muscles of the body, cardio activities function to increase the volume of oxygen intake because you breathe deeper and faster. This results in more oxygen being delivered to muscles and organs through increased blood flow while removing waste products such as carbon dioxide and lactic acid.
Benefits
Exercise scientist Steven Blair, in a January 2008 interview with "The New York Times," said, "Thirty minutes of moderate intensity exercise on five or more days of the week is really the bedrock dose. The fitness level associated with that dose effectively yields a 50 percent reduction in mortality risk. If you do more than the recommended levels by doing, say, 60 minutes of brisk walking or 45 minutes of jogging, you get another 10 percent to 15 percent reduction in mortality risk."
Daily Walking for Cardio
Regardless of your current fitness level, walking daily is a safe way to start a regular exercise program. The American Council on Exercise reports "regular walking can decrease total and intra-abdominal fat and reduce your risk of developing diabetes or breast cancer." Choosing walking as a daily cardio activity can also decrease blood pressure, help you reduce weight or maintain a healthy weight, and increase overall endurance.
FITT Formula
The frequency, intensity, time and type---FITT---of cardio activity not only influences results but determines how long it will take you to reach your goals. If you are engaging in walking your dog everyday for 30 minutes, but never break a sweat, then the intensity level falls below the moderate to vigorous level recommended for an improved health outcome, whether that be losing weight or reducing your blood pressure.
Warning
WomensHealth.gov warns against over-exercising, which is "when someone engages in strenuous physical activity to the point that is unsafe and unhealthy." The physical consequences of over-exercising can include "pulled muscles, stress fractures, knee trauma, shin splints, strained hamstrings, and ripped tendons."