HIIT vs. Steady State Cardio—Which Reigns Supreme for Optimal Fitness?

Cropped shot of a handsome young man using battle ropes during a high intensity workout outdoors

Jay Yuno / Getty Images

Whether your goal is to lose weight or get fit, cardio is an essential component to your workout program. Cardio is where you burn the most calories at one time; and cardio workouts strengthen your heart, lungs, and the muscles you're working.

Once upon a time, steady state training was the norm. You'd head outside or hit the treadmill for a walk or run, and stay at about the same moderate intensity throughout the workout.

In recent years, that has changed. High-intensity interval training (HIIT) is now popular. These workouts involve changing intensity—working harder for certain intervals—throughout the workout. These shorter, more intense workouts can give you more results in less time.

This article explains the differences between HIIT and steady state cardio, the pros and cons of each workout, and how to decide which option is right for you.

What Are the Differences Between HIIT and Steady State Cardio?

Steady State Cardio
  • Consistent speed and intensity

  • About 4-5 on perceived exertion scale

  • Moderate intensity

  • About 50-70% of maximum heart rate

HIIT
  • Alternate between intense work and rest

  • About 9-10 on perceived exertion scale for work and 3-4 for recovery

  • High intensity

  • About 80% to 95% of maximum heart rate

Steady state, or moderate-intensity cardio, is what many people 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.

HIIT involves pushing your body well out of its comfort zone for anywhere from five seconds to eight minutes, depending on the workout you're doing. The idea of HIIT is to work at about 80% to 95% of your maximum heart rate if you're monitoring your target heart rate zones, or a level 9 to 10 on the 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 work and rest intervals for 20 to 60 minutes total, depending on your fitness level, time constraints, and goals.

There is a lot of debate about whether HIIT or steady state training are more effective forms of cardio training for optimal fitness, yet research suggests that they may offer similar physiological challenges and results. A study published in 2015 in the Journal of Sports Science and Medicine found that HIIT and steady state were equivalent in improving both power and VO2 max, or the maximum amount of oxygen a person can use during exercise, after eight weeks of training.

Pros and Cons of HIIT Training

Pros
  • Improved performance

  • Improved insulin sensitivity

  • Improved calorie afterburn

  • Improved heart health

  • Shorter workouts

Cons
  • Can be uncomfortable

  • Not for beginners

  • Risk of injury

  • Risk of burnout or overtraining

Pros of HIIT Training

HIIT has a number of benefits, especially for people who already have some experience with exercise.

Improved Performance

Some studies have shown that while steady state training taxes the aerobic system, HIIT workouts can stimulate both the aerobic and anaerobic systems. That means your body has more stamina and performs better in all your workouts, no matter what they are.

Improved Insulin Sensitivity

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.

Improved Calorie Afterburn

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 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.

Helps to Reduce Abdominal Fat

Research shows that HIIT may be more effective at reducing abdominal fat than other types of exercise.

Improved Heart Health

HIIT training 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 HIIT sessions a week can make your body more efficient at delivering oxygen to your muscles as well as improving your metabolic health.

Cons of HIIT Training

HIIT training does have its disadvantages, and is not for everyone.

Can Be 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. So these workouts are tough.

Not for Beginners 

If you're coming from a completely sedentary lifestyle or returning to exercise 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.

Risk of Injury

High-intensity exercises like sprints, plyometrics, and jumps come with a risk of injury if your body isn't prepared for that kind of movement. According to professional trainers, wearing a top-rated pair of gym shoes is beneficial to preventing injury.

Risk of Burnout or Overtraining

Too much HIIT can be lead to burnout, an increased risk for dropping out of exercise. Experts recommend limiting HIIT workouts to one to two a week to avoid overtraining.

Pros and Cons of Steady State Training

Pros
  • Less stress on the cardiorespiratory system

  • Increased endurance

  • Improved health

  • Faster recovery

  • Improved ability to use fat for fuel

  • Increases slow-twitch muscle fibers

  • Can be more enjoyable

Cons
  • Time-consuming

  • Risk of overuse inury

  • Can be boring

  • Can cause weight-loss plateaus

Pros of Steady State Training

Steady state training also has plenty of benefits for your body.

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 build endurance in both your heart and your muscles.

Improved Health

Like HIIT, steady state 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.

Improved 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 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.

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.

Cons of Steady State Training

Naturally, there are disadvantages of steady state training as well.

Time-Consuming

To get the most benefits and build endurance you have to work out for longer periods of time with steady state cardio.

Risk of Overuse Injuries

Doing the same motions over and over can lead to repetitive stress injuries unless you do plenty of cross-training.

Boring

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 machine. That kind of workout can feel boring and tedious if you do it all the time. A pair of workout headphones can help make lengthy workouts less boring.

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.

Which One Is Right for You?

The best option really depends on your existing 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. So even if you try HIIT, it can be helpful to also include some steady state cardio to your weekly schedule for optimal fitness.

Try HIIT If...

  • You're an experienced exerciser comfortable with high-intensity exercise.
  • You want to focus on losing weight and burning more calories 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.

Stick With Steady State If...

  • You are a beginners or are coming back from a long exercise break.
  • You can't do high-impact exercise or don't like working at very high intensities.
  • You are 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).
  • You have been told to avoid high-intensity exercise by a doctor.

Build Up to HIIT Training

Beginners can build up 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.

Strategies for Doing Both

In a perfect world your exercise routine would include a mixture of both steady state and HIIT. It might look something like this:

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

Whether you decide to stick with steady state cardio or decide to add in some HIIT, you'll be doing great things for your heart, lungs, and muscles. Consistency is important so opt for workouts that you know you'll complete and that fit well into your schedule.

14 Sources
Verywell Fit uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. Tibana RA, De Sousa NMF, Cunha GV, et al. Validity of session rating perceived exertion method for quantifying internal training load during high-intensity functional training. Sports (Basel). 2018;6(3). doi:10.3390/sports6030068

  2. Foster C, Farland CV, Guidotti F, et al. The effects of high intensity interval training vs steady state training on aerobic and anaerobic capacity. J Sports Sci Med. 2015;14(4):747-755.

  3. Pearson SJ, Macaluso A, Hussain SR. High intensity interval training vs moderate intensity continuous training in the management of metabolic type diseaseMOJ Anat Physiol. 2015;1(5):134-139. doi:10.15406/mojap.2015.01.00027

  4. Greer BK, Sirithienthad P, Moffatt RJ, Marcello RT, Panton LB. EPOC comparison between isocaloric bouts of steady-state aerobic, intermittent aerobic, and resistance training. Res Q Exerc Sport. 2015;86(2):190-5. doi:10.1080/02701367.2014.999190

  5. Boutcher, SH. High-intensity intermittent exercise and fat loss. J Obesity. 2011;2011:868305. doi:10.1155/2011/868305

  6. Astorino TA, Edmunds RM, Clark A, et al. High-intensity interval training increases cardiac output and VO2max. Med Sci Sports Exerc. 2017;49(2):265-273. doi:10.1249/MSS.0000000000001099

  7. Smith-Ryan A, Trexler ET, Wingfield H, Blue MNM. Effects of high-intensity interval training on cardiometabolic risk factors in overweight/obese women. J Sports Sci. 2016;34(21):2038-2046. doi:10.1080/02640414.2016.1149609

  8. Ito S. High-intensity interval training for health benefits and care of cardiac diseases - The key to an efficient exercise protocolWorld J Cardiol. 2019;11(7):171-188. doi:10.4330/wjc.v11.i7.171

  9. O'Keefe JH, O'Keefe EL, Lavie CJ. The Goldilocks Zone for exercise: Not too little, not too much. Mo Med. 2018;115(2):98-105.

  10. Angadi SS, Bhammar DM, Gaesser GA. Postexercise hypotension after continuous, aerobic interval, and sprint interval exercise. J Strength Cond Res. 2015;29(10):2888-93. doi:10.1519/JSC.0000000000000939

  11. Ferretti G, Fagoni N, Taboni A, Bruseghini P, Vinetti G. The physiology of submaximal exercise: The steady state concept. Respir Physiol Neurobiol. 2017;246:76-85. doi:10.1016/j.resp.2017.08.005

  12. Hearris MA, Hammond KM, Fell JM, Morton JP. Regulation of muscle glycogen metabolism during exercise: Implications for endurance performance and training adaptations. Nutrients. 2018;10(3). doi:10.3390/nu10030298

  13. Zierath, JR, Hawley, JA. Skeletal muscle fiber type: Influence on contractile and metabolic properties. PLoS Biol. 2004;2(10):e348. doi:10.1371/journal.pbio.0020348

  14. Aicale R, Tarantino D, Maffulli N. Overuse injuries in sport: A comprehensive overview. J Orthop Surg Res. 2018;13(1):309. doi:10.1186/s13018-018-1017-5

By Paige Waehner, CPT
Paige Waehner is a certified personal trainer, author of the "Guide to Become a Personal Trainer," and co-author of "The Buzz on Exercise & Fitness."