If I am a beginner, can I do intervals in my cardio training?

Yes, you can! Here is a suggestion to consider. Think in terms of "intensity" on a scale from 1 to 10, consider 5 to be an easy warm up walk. Start with intensity 5 for 2 minutes and then increase your intensity each minute following to 6, 7, 8, 9 and then back down to 6, 7,8, and 9. Be careful to push yourself but pace yourself. Do what you can initially and work your way up to 20 minutes. Know that as your fitness levels improve, what it takes to reach a specific "intensity" level will need to change. For an extra push when you are ready, make your final minute of your cycle intensity 10 and then cool down for 2 minutes. This is just one way to incorporate intervals in your cardio training. Some find the way this specific interval training is outlined in the book Body for Life to be helpful.

If you are a beginner, it is not recommended to incorporate intense intervals in your initial training because you will first need to establish a good base of cardiorespiratory functioning. As a beginner, it is recommended that you begin training at intensity levels of 65 - 75% of your maximum heart rate for 20 - 60 minutes in order to build a strong cardio foundation. Once you are able to accomplish this, you can then progress to more advanced stages of training where you can begin introducing interval training into your program.

Of course you can.  However your intervals will be less intense than the normal interval training program.  You don't want your intensity too high or you will burn yourself out quickly or even injure yourself.  For starters consult your fitness professional to know what is the safest way for you to start interval training.  In some cases you may not even be ready for interval training but cardio is the one thing that improves the quickest when done consistantly.  Just remember when you first start out I always tell my clients baby steps.  You have to learn to crawl before you and run.

If you are beginner it is very important that you work toward developing a solid cardio foundation before you incorporate any interval training into your cardio program. Begin at an intensity of 65-75% of your maximum heart rate. Start slowly and work your way up to 30 to 60 minutes of cardio. Once you perform your cardio sessions maintaining your heart rate at this level for approximately two to three weeks, then you can progress to incorporating some interval training into your routine. 

To estimate your maximum heart rate, subtract your age from 220. For example, if you are 30 years old your maximum heart rate would be:

Estimated Maximum Heart Rate: 220 - 30 = 190 beats per minute (bpm).
                                65% x 190 =123 bpm
                                75% x 190 = 142 bpm

For this example, if you were 30 years old and just starting a cardio program, it is recommended that you try to keep your heart rate steady within a range of between 123 - 142 bpm, for a period of 30 - 60 minutes.

If you are a beginner, congratulations on getting started! You can do some intervals during your cardio training sessions, but it may be more beneficial to establish a base first. Your body needs at least a few weeks to actually build up your internal machinery to become more efficient with cardio. Starting off with anywhere from 2-60 minutes of cardio (whatever you can do!) at an easy to moderately challenging pace is the way to go. If you are monitoring your heart rate then you would want to work at 55-75% of your maximum heart rate. If you are not using a heart rate monitor or are not comfortable checking your heart rate then you can use the “talk test” or exertion scale to monitor your exercise intensity (more on that later). During exposure to a new cardio routine, your body builds capillaries, strengthens your heart muscle and engineers powerhouses in your cells. If you don’t give your body time to develop these adaptations and become more efficient then you won’t get as much benefit out of interval training. Using high intensity intervals without a proper “base” can even be dangerous. When figuring out your heart rate (HR) training zones you can use the Cooper or Standard method. Here is an example for a healthy 40 year.

Estimated Maximum Heart Rate: 220 – 40 (or your age) = 180 beats per minute (bpm) x the % you want to exercise at = your target heart rate. Select two numbers so you have a “zone” to operate in. This will help to establish training parameters for “Training Zone 1”.

To continue with our example; 

55% of max HR x 180 = 99 bpm

65% of max HR x 180 = 117 bpm

75% of max HR x 180 = 135 bpm

We could use 55% (99 bpm) as the low end of the zone and 65% (117 bpm) for the high end of the zone.  In this instance the exerciser would try to keep their HR between 99-117 bpm during their cardio workout. Of course they would perform a light warm up and cool down as well. If you were using the talk test in this situation instead of staying in that HR zone, we would make sure that the person could speak a few words without having to take breath. Gasping for air would mean that they were working too hard and being able to ramble on without stopping for a breath would mean it was too easy. As your conditioning improves you can slowly add interval training into your program.