HIIT vs. Steady State Cardio

Whether your goal is to lose weight or get fit, cardio is an essential component to your workout program. You know that cardio is where you burn the most calories at one time and, not only that, cardio workouts strengthen your heart, lungs, and the muscles you're working.

When we first started discovering cardio benefits, steady-state training was the norm. You'd head outside for a walk or run or hit the treadmill and, chances are, you would stay at about the same moderate intensity throughout the workout.

In recent years, that has changed dramatically. High-intensity interval training (HIIT) is now the hot ticket. These workouts involve changing the intensity, working harder for certain intervals throughout the routine.

These shorter, more intense workouts maximize your results while minimizing the amount of time you have to spend working out.

That sounds great, but is HIIT really better than steady-state cardio? Which one should you focus on if you're trying to lose weight and get fit? Even more important, can you enjoy your workouts if you're working at such a high intensity?

The Basics of HIIT

HIIT involves pushing your body well out of its comfort zone for anywhere from 5 seconds to 8 minutes, depending on the workout you're doing.

The idea is to work at about 80 percent to 95 percent of your maximum heart rate if you're monitoring your target heart rate zones, or a level 9 to 10 on this perceived exertion chart, also knowns as your rate of perceived exertion (RPE).

Each work set is followed by a recovery period which can be shorter, the same duration, or longer than the work set. In this interval, you get your heart rate down to about a level 3 to 4 perceived exertion. You alternate the intervals for 20 to 60 minutes, depending on your fitness level, time constraints, and goals.

Pros and Cons 

HIIT has a number of benefits, including:

• Improved performance: Some studies have shown that, while steady-state training taxes the aerobic system, HIIT workouts can stimulate both the aerobic and the anaerobic systems. That means your body has more stamina and performs better in all your workouts, no matter what they are.
• It improves insulin sensitivity: Insulin sensitivity refers to how sensitive your body is to the effects of insulin. The more sensitive your body is to insulin, the less your body needs that insulin to lower blood glucose levels. In terms of exercise, that means your HIIT can help your exercising muscles use glucose for fuel more efficiently.
• It helps you burn more calories all day long One of the best benefits of HIIT is how many calories your body burns after your workout to get your system back to where it was before you exercised. This is also called post-exercise oxygen consumption (EPOC), or your afterburn. The harder you work during your workout, the longer it takes your body to get back to normal, meaning you'll burn more calories for an hour or more after your workout.
• It helps you burn more belly fat: Even better news is that research is showing that HIIT may be more effective at reducing abdominal fat than other types of exercise.
• It improves your health: HIIT can help lower blood pressure and improve your heart health.
• Shorter workouts: Because you're working very hard, you get the benefits of training in less time than you would from slower, longer workout sessions. One study published in The Journal of Sports Science and Medicine showed that as few as three 10 minute sessions a week can make your body more efficient at delivering oxygen to your body as well as improving your metabolic health.

On the other hand, HIIT has some drawbacks, including:

• Can be extremely uncomfortable: While you can modify the workouts to fit your fitness level, the idea is to get as far out of your comfort zone as you can.
• Isn't great for absolute beginners: If you're coming from a completely sedentary lifestyle or returning after an injury, HIIT is probably not where you want to start. You should have a basic foundation of cardio training before trying HIIT. If you are in good health and active, you can modify if necessary.
• Increased risk of injury: High-intensity exercises like sprints, plyometrics or jumps come with a risk of injury if your body isn't prepared for that kind of movement.
• Can lead to burnout or overtraining: Too much HIIT can be lead to burnout, an increased risk for dropping out or an increased risk of injury in certain people. Experts recommend 1-2 HIIT workouts a week to avoid overtraining.

A Sample HIIT Workout

HIIT workouts can be set up in a variety of ways. For example, Tabata Workouts involve working very hard for 20 seconds with only 10 seconds of recovery time. You repeat that again and again for a total of 4 minutes, as in this cardio Tabata workout.

You can also do workouts with a longer work interval, such as high-intensity work for 40 seconds and recovery for 20 seconds, as in this 40-20 high-intensity interval workout.

The shorter the recovery times, the harder the workout is since you're never fully ready for the next work set.

The following workout involves a variety of high intensity, high impact cardio exercises and a 1:1 work to rest ratio. Modify jumping movement to low impact if you need to.

That means your work sets and rest sets are the same duration. The idea is to keep going, even as you get fatigued towards the end of the workout, although if you feel dizzy or feel that you can't catch your breath, you should take longer breaks.

Steady-State Cardio

Steady-state or moderate-intensity cardio is what many of us are used to. This involves exercising at a consistent speed and level of intensity for the entire workout. That would be at about level 4 to 5 on the perceived exertion scale.

The idea is to work at a level where you can talk with maybe just a little difficulty.

Pros and Cons of Steady-State Training

Steady-state training also has some benefits such as:

• Less stress on the cardiorespiratory system: Because you're working at a lower intensity, you can improve your endurance without putting as much stress on the heart and body as higher intensity exercise.
• Increased endurance: Longer slower exercise helps you build endurance, both in your heart and your muscles.
• Improved health: Like HIIT, cardio makes your heart more efficient, getting oxygen to the muscles more quickly. Steady-state cardio also lowers blood pressure, reduces stress and anxiety and, along with a healthy diet, can help you lose weight.
• Faster recovery: Because you're putting less stress on your heart and body, you recover more quickly and can usually work out the next day without a problem.
• It improves your body's ability to use fat: When you work at a lower intensity, fat is your main fuel source. Staying at that level allows you to save those glycogen stores for higher intensity workouts. That doesn't necessarily mean you burn more fat, just that your body is better at using fat for fuel.
• It increases slow-twitch muscle fibers: Slow twitch muscle fibers are more efficient at using oxygen to generate energy, so you can go for a longer period of time. This improves your aerobic metabolism which is, essentially, how your body creates energy.
• More enjoyable: Part of the reason we stick with exercise is that, on some level, we like it. Or at least we can tolerate it. It's much more comfortable to work at a lower level of intensity than it is higher intensity. Some exercisers may even quit after too much intense exercise just because it's so uncomfortable.

Some of the disadvantages of steady-state training include:

• The time factor: If you're trying to lose weight, you have to work out for longer periods of time if you want to burn enough calories.
• Risk of overuse injuries: Doing the same motions over and over can lead to repetitive stress injuries unless you do plenty of cross-training.
• Boredom: Not everyone is cut out for long, slow workouts, especially if the weather is bad and you have to get on a treadmill, stationary bike or other cardio machines. That kind of workout can feel boring and tedious if you do it all the time.
• Weight loss plateaus: Doing only steady-state cardio workouts without changing things up could lead to a plateau. You need to challenge your body with new and different activities so it can constantly change and grow stronger.

Should You Do HIIT, Steady State, or Both?

With all that in mind, which one is right for you? The answer really depends on your fitness level and goals more than anything else. And keep in mind that experts don't recommend doing HIIT more than twice to three times a week.

Who Should Try HIIT?

• You're an experienced exerciser comfortable with high-intensity exercise.
• You want to focus on losing weight and burning more calories both during and after your workouts.
• You want shorter workouts because of a busy lifestyle.
• You want workouts that mix up different exercises and intensities to keep things interesting.
• You want to build endurance quickly.

Who Should Stick With Steady-State?

• Beginners or anyone coming back from a long exercise break.
• Anyone who can't do high-impact exercise or doesn't like working at very high intensities.
• Someone training for an endurance race, such as a half-marathon or marathon, although you may do some high-intensity work depending on the training plan you're following.
• Anyone who's been told to avoid high-intensity exercise by a doctor.

Best of Both Worlds

In a perfect world, you would have some mixture of both steady-state and HIIT. For beginners, you can actually build up your endurance and stamina for HIIT training by starting with aerobic interval training.

That involves changing up your intensity just enough to push you out of your comfort zone, but not so far out that you're miserable or breathless. This beginner interval workout is a great place to start.

As you practice, you can start to increase the intensity of your intervals from week to week.

The other key to working up to HIIT is consistency. Doing cardio on a regular basis is how you build the foundation that will allow you to work harder and get more out of your workouts.

Sample HIIT/Stead State Cardio Schedule

Day 1: 30-minute sprint interval workout
Day 2: 40-minute cardio endurance workout
Day 3: Rest or light activity
Day 4: 25-minute Tabata cardio challenge
Day 5: 30 or more minutes of moderate cardio, like walking, jogging, cycling, etc.
Day 6: Rest or light activity
Day 7: 30-minute aerobic cardio or rest