Burning Debate: What kind of cardio is best?

Cardiovascular training varies in its degree of impact, level of intensity, and duration of exercise. You should pay close attention to these factors before you select a fitness routine. The current condition of your body will help determine the proper type of cardio training for you. After reading this post you will be one step closer to knowing what kind of cardio is best for your specific needs and goals.

Basically, there are two main types of cardiovascular training you need to know about:

• Low-intensity steady state cardio (slow prolonged duration cardio training) or “LISS”, which is equivalent to 45-90 minutes of walking or any other form of low-intensity cardio.
  
• High intensity interval training (HIIT), which is equivalent to a 30-second sprint (defined as ‘work’), followed by a 30-second walk/jogging (defined as ‘rest’). These ‘work’ and ‘rest’ periods are then repeated for a designated amount of time, usually 10-20 minutes.

Both types of training can easily be applied to any mode of cardiovascular exercise – running, cycling, stationary bike, stepping machine, elliptical trainer or any other cardio machine.

Steady state or HIIT? What kind of cardio is best?

As already stated above, there are two schools of thought: old school with long duration low-intensity cardio sessions (45 to 90 minutes at a steady state) and the new school recommending high-intensity interval cardio (HIIT). Who is right? What kind of cardio is best?

The purpose of cardio in bodybuilding

Actually, the purpose of cardio in bodybuilding is to burn off body fat and improve your cardiovascular health. The old way of doing cardio is quite effective since it keeps your heart rate at a steady level for a prolonged period of time. This is the kind of cardio we would recommend right after training with weights in order to achieve maximum fat loss. During weight training you achieve glycogen depletion, which means that the body will burn fats for energy in the follow-up cardio session.

Beginners and athletes recovering from injury

Beginners can perform low-intensity steady state cardio and benefit greatly because their bodies don’t require very high intensities to respond and make changes. Also, low-intensity cardio is very easy on the joints, muscles and respiratory system. That is very convenient for those just starting (or restarting) an exercise program. Also, athletes recovering form injury will benefit from this type of cardiovascular training.

Higher energy output

High intensity cardio training (HIIT)  also has its merits. It creates a higher energy output than steady state cardio, and it saves time because sessions are usually only about 15 to 25 minutes. A typical session would look something like this: 8 minutes warm-up, 6 sets of 30-second sprints, 90 seconds easy, 5 minutes cool down.

Excess post-exercise oxygen consumption

Your heart rate is much higher when performing HIIT cardio and your basic metabolic rate (BMR) stays elevated for 24 hours after the session, which means you burn some additional calories after the session. That’s not the case with the steady state cardio where you burn calories and fat only during the cardio session.

In other words, HIIT produces a greater “after burn” or EPOC (excess post-exercise oxygen consumption), and speeds up your metabolic rate for up to 24 hours after your workout. This means while you’re relaxing in your family room watching TV after completing your HIIT training session you will continue to reap the benefits of your workout because your body will continue to burn oxygen, calories, and fat at a higher rate for many hours. If you are pressed for time, 30 minutes of HIIT will burn more calories than regular low-intensity cardio. This is one of the most important benefit of HIIT.

Energy source

The main drawback of HIIT is that while some of the energy comes from fat, most of it is derived from reserves of carbohydrate (glycogen inside the muscle). This is an inefficient way of losing fat. The best way is to burn fat rather than carbohydrate.

Exactly which energy source is preferred during physical activity is based upon the level of intensity that’s required. Exercising with a relatively high level of intensity uses a greater percentage of carbohydrates as an energy source; exercising with relatively low level of intensity uses a greater percentage of fat as an energy source.

Going to the limit

There is another potential drawback of HIIT. Making use of the interval method is not an easy task. Going to the limit during intense interval trainings makes you feel as if your heart is going to burst. This can be painful and you will probably run out of breath fast.

Cardiovascular plateau

If you are an avid exerciser, steady state training will maintain your fitness level and you will eventually reach a cardiovascular plateau. To improve your fitness level, think about incorporating some interval training into your program to change your routine and make your body work harder via active recovery.

Speed and power development

Finally, interval cardio training is also going to work on your speed and power development as well, as you’ll rapidly have to accelerate quickly when doing each interval.

So why not just perform HIIT every time? Because it can be too stressful on your recovery and lead to over training. We would recommend 1 to 2 HIIT sessions on non-lifting days and 2 low-intensity sessions after your regular weight workout if maximum fat loss is your goal. Personally, I don’t believe that that much cardio is warranted if your diet is in check.

Closing thoughts: What kind of cardio is best: steady state or HIIT?

While it’s probably true that exercising at the lower zone will burn more calories in the form of fat, exercising in the higher zone (HIIT) will certainly burn more calories overall for the same amount of time. And since total calorie expenditure is the key to losing fat, theoretically the higher zone should be the best zone.

Despite what we have said, there is no best form of cardio. The key word there is “should” as everyone’s body responds differently. The lower zone may work best for you. Do not force yourself to perform a type of cardio you dislike.

If you have little time, high-intensity cardio is the way to go. If you have the choice, pick the form you like best because it will ensure that you keep doing it in the long run.

Our advice is to start out at the lower zone and gradually work into the upper zone and see what happens. If there is a noticeable difference then select the one that works best. If on the other hand both seem to be yielding equal results, then alternate them for diversity. You can alternate them on a daily basis (i.e. high, low, high, low, etc), or one month high and the next low.