HIIT or Cardio: Which is the Better Choice for Weight Loss?

The popularity of HIIT (high-intensity interval training) has soared in recent years, as more people discover its effectiveness as a rigorous workout option. But when it comes to weight loss, is HIIT superior to traditional cardio exercise?

Understanding HIIT The essence of HIIT lies in its name: high-intensity cardiovascular exercise interspersed with rest periods. According to Jessica Brown, a certified fitness trainer and founder of the Glute Recruit, HIIT is an extreme workout program that enhances endurance, strength, and promotes faster weight loss compared to low-intensity cardio.

Specifically, HIIT involves reaching a higher heart rate for short bursts of time. Typically, you cross the high-intensity threshold, which is around 80% of your maximum heart rate, when you find it difficult to catch your breath or carry on a conversation.

In some cases, highly intense HIIT workouts push individuals to reach 90% or even 100% of their maximum heart rate for brief periods, intensifying the workout. To determine your maximum heart rate, subtract your age from 220.

Many people enjoy the sensation of pushing themselves to 90% to 100% of their maximum heart rate, as it creates a feeling of increased exertion with heavier breathing and muscle burn, explains Joel Freeman, a fitness trainer and entrepreneur based in Los Angeles.

So, what does a full HIIT workout entail?

“For example, a HIIT session could involve going for a jog and sprinting for 30 seconds every three minutes. It could also include performing as many chest presses as possible with a high weight for 60 seconds in between treadmill walks,” says Megan Wroe, a registered dietitian and wellness manager at Providence St. Jude Medical Center in Fullerton, California. “This type of training challenges your cardiovascular system by raising and lowering your heart rate, ultimately providing more benefits for your efforts.”

During rest periods in HIIT workouts, active rest is often incorporated, involving light activities like walking or jogging, which are longer in duration than the strenuous exercise intervals. Overall, most HIIT workouts can be completed in 10 to 30 minutes, which is often shorter than the time required for a full cardio conditioning or strength training session.

SEE: Strategies for Gaining Muscle While Losing Weight.

Benefits of HIIT The HIIT approach offers several advantages, including effective workouts, weight loss, and health benefits.

“HIIT is an excellent way to lose weight in less time,” says Brown. “In a 20-minute HIIT workout, most people can burn the same number of calories as they would during 45 minutes of continuous cardio or strength training. HIIT also improves lung capacity and blood flow in the body.”

Additionally, HIIT can elevate your resting metabolic rate, causing you to burn calories for up to 24 hours after your workout. According to Brown, HIIT can help burn more fat rather than muscle, which can sometimes occur with steady-state cardio.

Moreover, HIIT can contribute to trimming your waistline.

“People can continue building muscle mass while shedding excess fat in challenging areas such as the lower abdomen and thighs,” explains Brown.

Limitations of HIIT However, there are limits to what HIIT can achieve, warns Thomas Roe, a fitness trainer and endurance athlete based in San Antonio, Texas.

“High-intensity interval training, such as group or circuit training that involves minimal downtime between stations, can aid in weight loss, but only when combined with a low-calorie diet or nutrition plan,” he says. “You can’t out-train a poor diet.”

What you do in the gym must align with what you consume in the kitchen. Without operating on a caloric deficit—burning more calories during your HIIT workouts than you consume—it may be challenging to lose weight.

“You need to focus on your diet. There’s no way around it,” advises Janet Lee, a doctor of Chinese medicine, yoga instructor, and health journalist based in Kansas City, Missouri. “Try to control your portions and restrict your calorie intake. It ultimately comes down to calories in, calories out, for the most part.”

SEE: 12 Tips to Maximize Your Workout Results.

Understanding Cardio HIIT is a type of cardio exercise, but what exactly is cardio?

“Cardio is any form of exercise that elevates your heart rate and increases oxygen and blood flow throughout the body while utilizing large muscle groups,” explains Roe.

Common examples of cardio exercises include running or jogging, cycling, long-distance swimming, treadmill or elliptical machine workouts, and rowing. Unlike HIIT, cardio workouts typically last for a minimum of 20 to 30 minutes, performed at 60% to 70% of your maximum heart rate. They lack the intense bursts of activity found in HIIT and may be perceived as monotonous due to their longer duration and steady pace, according to Freeman.

However, these longer cardio sessions are effective for building stamina and can aid in weight loss. While the calorie and fat burn may be lower compared to a typical HIIT workout, cardio still contributes to a caloric deficit.

One important note: Although cardio can lead to weight loss, it is especially beneficial for individuals transitioning from a sedentary lifestyle to a more active one.

“Over time, this type of movement becomes more of a maintenance phase since it aligns with how our bodies are naturally meant to move, resulting in reduced stress once the body adapts,” explains Wroe. “This is where many people hit a weight plateau, and HIIT can help break through that.”

In addition to supporting weight loss, cardio— as the name suggests— is excellent for cardiovascular health. It strengthens the heart and improves endurance, which are vital components of overall well-being and longevity.

“Cardio is great for the cardiovascular system and promotes overall fat burning,” says Freeman. “It also releases endorphins, the brain chemicals responsible for the ‘runner’s high’ sensation.”

SEE: 5 Tips for Properly Warming Up Before a Workout.

Which Is the Better Option? For individuals with busy schedules seeking efficient workout options, HIIT workouts can be appealing. However, it is important to note that there isn’t a one-size-fits-all answer to determine which type of exercise is better.

“I always hesitate to say that one is superior to the other because there are various factors to consider,” points out Freeman.

When working with clients, Freeman takes into account their time availability and physical limitations before recommending a specific approach. There isn’t a universal solution for everyone.

For instance, Shaun Carrillo, lead wellness coach at Providence St. Joseph Hospital in Southern California, suggests that HIIT may not be the best choice for beginners or individuals with joint issues. In such cases, a low-intensity steady-state cardio workout may be more suitable.

On the other hand, if you enjoy a diverse range of exercises during your workouts, HIIT might be the preferred option due to its alternating exercises at shorter intervals.

However, it’s important to note that HIIT workouts should not be performed every day, warns Brown.

“HIIT workouts place a significant strain on the body and should be alternated with less intense workouts like walking or yoga to avoid injuries,” she explains. “If you feel fatigued, experience heavy legs, or find it difficult to perform your daily activities, it might be a sign that you’re overdoing it with HIIT exercises.”

Lee suggests aiming for two to three high-intensity workouts per week and incorporating strength training and cardio on other days for optimal results.

Establishing a Daily Exercise Routine When it comes to selecting the best exercise to support your weight loss goals, it’s essential to choose a workout that doesn’t feel like a chore.

“Choose a form of exercise that you enjoy and remain consistent, even if you don’t see immediate results,” advises Mara. “There will be times when you hit a plateau, and that might be an opportunity to change your routine or intensity.”

If you dislike exercising, it’s possible that you haven’t found the right type of exercise for you. If you’re struggling to find the ideal workout regimen, consider working with a trainer who can introduce you to new options that you may not have considered before.

Lee adds that if you find it more approachable to exercise for less than 30 minutes, start with that.

“Make the most of it. If you’re going to spend 20 minutes walking on the treadmill, that’s better than sitting on your couch. But try to elevate your heart rate and intensity during those 20 minutes,” she suggests.

You can increase your speed, incline, or both to make the workout more challenging. By working hard during those 20 minutes, you can potentially burn as many calories as you would in a 30- or 45-minute session, she notes.

Roe recommends seeking the assistance of a fitness trainer with experience in weight loss and inquiring about their own fitness or weight loss journeys. Trainers who have successfully managed their weight may be particularly helpful, as they can relate to your experience and assist you in creating a personalized plan and schedule to reach your goals.

The Importance of Building Muscle for Weight Loss As mentioned earlier, strength training workouts can also contribute to weight loss. As you build more strength and muscle, your body will burn more calories 24/7, as muscle burns more calories than fat.

Freeman suggests not obsessing over the numbers solely within the exercise period if you use a wearable fitness device that tracks calories burned.

“Transform your body into a calorie-burning machine not just during the workout but throughout the day,” he recommends. “Sustained weight loss is more achievable by increasing muscle mass, as it boosts your metabolism.”

Roe also emphasizes the significance of setting realistic goals and finding someone who can hold you accountable, such as a trainer, support group, or team.

Lastly, don’t let a lack of immediate progress discourage you.

“Weight loss is a journey and doesn’t happen overnight. It’s important to be patient and not get discouraged,” says Brown.

Consistency is key—make exercise a non-negotiable part of your daily life, just like meal planning.

“Essentially, integrate it into your lifestyle,” advises Brown.