Cardio vs. High Intensity Interval Training
Christopher Smith, PT Pulse Fitness
When it comes to cardiovascular exercise and its many desired benefits such as burning fat and boosting heart health it turns out that slow and steady doesn’t win the race. Short intense bursts of physical exertion with short breaks in between have been shown to be much more effective than long durations of cardiovascular exercise with a consistent intensity level throughout. Although recent research has discovered this to be true, this style of exercise is in fact ancient and is exactly what our ancestors did when hunting and escaping from being another animal’s prey. This “stop and go” activity is also how all of us as children naturally play.
What exactly is HIIT?
HIIT or High Intensity Interval Training is a style of exercise that involves exerting to near maximum for short durations lasting less than a minute with very short periods of rest. A great example would be sprinting for 20 seconds with a 15 to 20 second rest and repeating for 10 to 20 minutes. This can be done with almost any exercise and is not limited to just running.
Why do HIIT vs. Aerobics?
HIIT gives all of the same benefits of steady pace exercise or “Aerobics” with less than half the time as well as a significant increase in these benefits over aerobics alone. To achieve these benefits exercises must be performed with at least 85% or higher of heart rate maximum.
What are the benefits of HIIT?
Studies have shown that high intensity interval training is more effective than aerobic exercise at increasing growth hormone, testosterone, and nitric oxide release, improving insulin sensitivity and metabolism.
What does this mean for you?
These intermittent bursts of activity at or near maximum effort stimulates a higher excess post-exercise oxygen consumption which means more calories are burned and metabolism stays elevated longer, up to 24 hours after exercise. Aerobics alone will only provide up to 4 hours of continuous metabolic increase.
– Insulin Sensitivity:
Type II Diabetes is a form of insulin resistance; this is when insulin has a more difficult time doing its job than normal. HIIT induces better metabolic adaptations within the muscle cells allowing insulin to effortlessly perform its duty which is allowing glucose to be used as fuel.
– Growth Hormone and Testosterone:
Growth Hormone has been hailed as the “Youth Hormone” for man years now since its discovery. It is responsible for keeping our tissues healthy and strong as well as keeping us lean. Think of the sprinter body vs. the endurance athlete or marathon runner. Sprinters are typically very lean and muscular while marathon runners have muscle atrophy, appear gaunt and wiry.
Nitric oxide is essential for heart and arterial health. It is naturally produced by the endothelium within the arterial walls of our arteries; it keeps the walls of our arteries elastic, stabilizes blood pressure through vasodialation, and enhances the immune system.
Comparing HIIT at 90% maxHR vs moderate intensity aerobics at 70% maxHR showed a significant improvement in VO2max as well as increased Nitric Oxide production.