Physical Exercise

Throughout history, physical activity has had a large impact on the lifestyle of mankind. Whether physical activity was used during hunting or transportation in the early years of mankind or today in sports and play it has and will continue to have an impact on our lifestyles. As technology advanced and the uses of physical activity was needed less for survival it began to become the center of sport and leisure activities. It hasn’t been until the last couple of hundred years that physical activity, in the form of exercise, has been studied in the clinical realm. The use of exercise in the clinical world is defined as exercise physiology which is the study of how exercise influences the structure and the function of the human body (Robergs,

A widely used exercise test is performed on a treadmill. Since exercise has been used as a diagnostic tool, there have been many different protocols for how a test should be conducted on the different equipment. The most common used protocol for treadmill exercise tests done today is the Bruce protocol, as 82% of the surveyed cardiology divisions said they used the Bruce protocol (Ashley, Myers, & Froelicher 2000). This protocol was developed by Robert Bruce in 1963. The Bruce protocol involves different stages of the test; each stage of the test is performed for three minutes before moving to the next stage. The speed and incline of the treadmill is increased in each stage. The speeds for each stage are as follows, 1.7, 2.5, 3.4, 4.2, 5.0, 5.5, and 6.0 miles per hour. Along with the speed, the incline is increased from horizontal as follows, 10, 12, 14, 16, 18, 20, and 22 % Grade (Weber & Janicki 1986). The advantage of the Bruce protocol is outweighed by many participants unable to complete one stage as they have cardiovascular impairments and find this level of intensity too difficult (Ashley, Myers, & Froelicher). Because of the difficulty of the Bruce treadmill protocol, the Ramp testing was developed and introduced in 1991. This protocol is conducted by bringing the subject from rest to maximum effort through a linear increase of exercise over a period of about 10 minutes (Ashley, Myers, & Froelicher, 2000). The Duke Treadmill Score is an equation that is used to calculate the 5 year mortality rate. This is achieved by examining three different variables: ST depression, exercise capacity, and presence of angina. The equation is as follows: DTS = EXmin – (5 x STdev) - (4 x ANGex). This equation will give you a typical score from -25 to +15 rating of low