In 1969 Kenneth Cooper wrote the book “Aerobics” and coined that term to describe a form of exercise. Before that the word aerobic was more often used to describe a type of metabolism. Aerobic metabolism utilizes our energy stores in conjunction with oxygen, while anaerobic metabolism uses those energy stores without the oxygen.

Both metabolic pathways are working all the time. The aerobic pathway is predominant at rest or at lower intensity steady-state activities such as walking and jogging. The anaerobic pathway kicks in at higher levels of intensity for activities such as sprinting or strength training.
Cardio exercise is exercise that produces a sustained elevated heart rate at a range of 60% to $85% of one’s maximum heart rate.
Can strength training have a significant cardiovascular component? It can; it depends on how your workout is structured. Warm-up sets do not present great demands on the cardiovascular system or the muscles for that matter. Intermediate intensity sets, time resting between sets, or set up time for the next exercise will not be taxing to the cardiovascular system. In the course of an hour workout there can be significant time where cardiovascular demands on the body are minimal.
With High Intensity Interval Training (HIIT) for strength there is very little rest and a very large cardiovascular component. At the end of the first exercise your body will be doing all that it can to accommodate the demands placed on the system – the heart rate increases, arteries dilate, venous return increases, and blood volume per beat of the heart increases.
Follow that first exercise with a non-stop series of strength training exercises addressing all the major muscle groups. The workout will take about 20 minutes; it really can’t be sustained much longer than that unless you pace yourself, i.e. workout at a lower intensity. It is best to have an experienced trainer to help get you through the workout at a sustained high intensity level. [At Kelly’s Austin Personal Training and at New Orleans Ultimate Fitness training our workout program involves high intensity interval training.]
The cardio demands can be quite high. I have a 58 year old client who is in superb physical condition go through the workout wearing a heart monitor. At the end of the first exercise her pulse was 150. Upon completion of the last exercise her pulse reading was 148.
A properly conducted HIIT regime will result in increases in strength, muscle, bone density, flexibility, muscle tone, resting metabolism, and cardiovascular conditioning. You will look and feel better, and your life can be transformed in minutes a week. The workout requires less time; runners and tri-athletes can spend less time in the gym and have more time to spend running or doing other forms of aerobic exercise. They often see improvements in their performance.
More information here > Study Examining Benefits Of High Intensity Interval Training
Really interesting post. I
Really interesting post. I always knew that the three were very important for an effective fitness routine, but I didn't know the difference between cardio and the other two. Thanks for the info!