Do you wonder how Michael Phelps constantly improves his cardio fitness, since your hour run or swim isn't cutting it anymore? Successful athletes have great talent and a hard work ethic, but to continually see victory, most interval train; something that can easily be added to any person's cardiovascular exercise
Interval training is when your workout involves cycles of high intensity and low intensity exercise. It's giving bursts of hard work, and then allowing time to recover before you exert another burst of high intensity. An example is when you continuously sprint for a minute, and then jog for a minute.
Interval training works great to improve your cardiovascular system because it mixes up your routine, causing your body to constantly work hard. It prevents the adaption process or doesn't allow your body to get use to an exercise. Think of an activity at work you're responsible for. When you were first assigned this task, your brain had to really think hard to complete the job. After about a month or two, though, that task most likely became second nature to you, so your brain did not have to think as hard to complete the task. If you let this happen to your workout, your body gets use to a routine, causing the workoad to not be there anymore (and thus prevents fitness improvement). Interval training mixes up your workout enough to keep your body thinking about what it is doing.
Anaerobic and Aerobic Exercise
Interval training includes anaerobic and aerobic activity, causing your heart and lungs to work harder, and giving you a results-oriented workout. Anaerobic refers to the high intensity point in your exercise, or when you are lackng oxygen. This is when stored glucose and fat are burned while your heart is working at 85 percent peak capacity. At this intensity level, your muscles are being forced to not rely on oxygen to fuel muscle contraction, and during this period, lactic acid is formed. Lactic acid causes your muscles to break down and fatigue, making your exercise intensity to eventually decrease. You know lactic acid is forming when the burning sensation takes over your muscles.
Aerobic refers to the recovery point in your cardio session, and it is when your body refuels on oxygen. This is the point in your exercise where your heart and lungs have to work extra hard to pay back that oxygen deficiency, and break down the lactic acid that was accumulated. During the aerobic stage of your workout, you are building stamina. By having a recovery period throughout the workout, your body is able to exercise longer, leading to a gradual cardio improvement.
Put together a cardio workout that includes intervals next time you hit up the gym to reach your next fitness goal. But remember to always pay attention to your body and to not over-exert yourself. This is especially true in the first week or two of trying a new exercise. Ending up at the doctors is not the goal!