During one-hour cardio sessions, it is easy to get bored and feel like a hamster running on a wheel. If you do your cardio outdoors, then you can be a bit more adventurous. However, if you are running the same routes over and over eventually, you will become bored. Fortunately, if you want to add variety to your training and try other exercise regimens, there is a solution. It is called high-intensity interval training. This exercise program encompasses repeated high-intensity interval exercise bouts interspersed with passive or active recovery periods. In simple terms, you run fast and run slow for a specified number of intervals. However, to optimally apply high-intensity interval training, your heart rate should dictate how fast or slow you run during each interval.
|Heart Rate Zone||Heart Rate Percentage||Energy Source||Example|
|Zone One||65-75%||Muscle Glycogen and fatty acids||Walking or jogging|
|Zone Two||80-85%||Muscle glycogen and lactic acid||Group exercise classes|
|Zone Three||86-90%||ATP/CP and muscle glycogen||Sprinting|
To use high-intensity interval training, you first need to determine your max heart rate. One can easily calculate their max heart rate by using the following formula, 220-age. Therefore, if you are 20 years old, your max heart rate would be 200 because 220-20=200. Now, that we have an example, there are multiple heart rate zone training methods you can apply to your exercise program. Each zone is typically categorized by a percentage of your heart rate and uses different energy sources. In my personal experience, using high-intensity interval training while monitoring my heart rate has achieved the best results, especially when I implement these exercises with a heart rate monitor. These heart rate monitors come with a strap you place around the bottom of your chest and a watch. These devices allow you to input your information, determine your desired heart rate, and can also calculate the calories you expend. Some popular brands available at your local Best Buy or Academy Sports + Outdoors include Polar and Garmin. If you are using a heart rate monitor while on the treadmill or elliptical, you would be glad to know the cardio machine will read your heart rate automatically. There will be no need to wrap your sweaty hands around the heart rate sensors to know your heart rate. This is often seen as an inconvenience as it disturbs your cardio session. Using a heart rate monitor is more efficient and mitigates any disruptions during cardio. Now that we have this covered we can explore the three heart rate zones that can be used in your high-intensity interval training program. I have also given examples of how each zone feels just in case purchasing a heart rate monitor is unfeasible.
As you can see from the example, your heart rate increases as you progress through each stage. So, if you are 20 years old with a maximum heart rate of 200 then your Zone One heart rate would be 130-150, Zone Two would be 160-170, and Zone Three would be 172-180. If you know this information, then you can apply low, medium, and high-intensity interval training to your exercise program. Currently, there are various variations of interval training available; I will give you one example you can apply to your training regimen as well as an alternative.
First warm up for 5-10 minutes in Zone One, if you are wearing a heart rate monitor you will see your heart rate pop up on the cardio machine screen. Now, after you feel loose and are ready to go, you can increase your heart rate to Zone Two and keep it there for approximately two minutes. Bear in mind if you are out of shape you will notice your heart rate sky rocket, and if you are in the best shape of your life, you will notice how hard it is to increase your heart rate. Therefore, be self-aware and maneuver the resistance and incline settings to your cardio machine appropriately to meet your desired heart rate. Now, when the two minutes expire you will need to increase your speed or the resistance of the cardio machine to enter Zone Three. You will stay in Zone Three for one minute. At this stage, the level of difficulty is almost at a max; you will be working at an intense level which is not sustainable for the average person. After, this stage your goal should be to decrease your heart rate within one minute to Zone Two. This step will be difficult if you are not in shape. Take two minutes or three if needed. Your last step before you can repeat the whole process again would be to decrease your heart rate to Zone One. If you are having difficulty reaching Zone One after completing this interval, there are other training regimens you can apply to improve your cardiorespiratory fitness.
If you need an alternative running program, keeping the heart rate between Zone One and Two should be prioritized to build your foundation. Bear in mind the following example can be used for elite athletes who need a low to moderate-intensity interval day. Similar to the aforementioned example, a 5-10-minute warm-up under Zone One will start the session. Next, you will need to increase your rate to Zone Two for one minute then gradually decrease your heart rate to Zone One for another 5 minutes before completing the interval again. The number of intervals you will complete will be dependent on your cardiorespiratory fitness, keep in mind you should finish your cardio session at Zone One. On a side note, if you are an elite athlete this alternative running program can easily be applied to your endurance level by just increasing your heart rate to Zone Three at each interval rather than Zone Two.
Overall, using high-intensity interval training is a great way to add variety to your training program. However, it is not for everyone; there are alternative to this method such as the moderate-intensity interval example mentioned above. If you are not an elite athlete using this method should be prioritized before diving into advanced interval training programs. Doing so will improve your running form and mitigate the risk of orthopedic injuries such an ankle, knee, or hip injury. Therefore, be self-aware and prudent when applying these training methods to your cardio sessions.
-Robert E. Salazar, MS, RDN, LDN