Training For Fat Loss: LISS or HIT—What’s The Best Way To Lose Body Fat?

It’s become in vogue to say that low-intensity steady-state cardio (LISS) is the go-to training mode for fat loss. This trend is a shift from the extreme popularity of higher intensity training (HIT) protocols in recent years. It’s unknown what has inspired this shift:

Are people just too stressed out to make it through a tough HIT workout?

Maybe they are doing HIT too often, inhibiting recovery and getting rundown?

Perhaps they haven't learned proper technique and are getting injured?

Either way, it’s important to know that while LISS cardio can be useful for reducing body fat, it’s likely to leave you with diminishing returns.

What’s Wrong With Doing LISS Cardio Long-Term?

For people who are new to exercise, LISS cardio (typically defined as walking, cycling, or other cardio machine) can lead to a temporary loss of body fat in the range of 1 to 5 pounds over 3 months. It’s a great way to kickstart fat loss and develop a base level of conditioning, while also establishing a regular training habit that will be with you for life.

The problem is that low-intensity exercise trains the body to become more efficient. This means that the amount of energy it requires to jog 2 miles will decrease as you begin to get in shape. When you were originally burning 300 calories in a workout, your body will adapt and now may burn only 250.

Additionally, low-intensity training leads to the loss of lean mass over time. It has a muscle degrading effect, especially when combined with a lower calorie diet. The end result is that your metabolic rate drops, but your body is more efficient. To continue losing body fat you have to progressively increase your training time or eat less—something that is virtually impossible for most people.

The reality is that the majority of people who initially lose fat with low-intensity cardio will regain that weight even if they maintain their exercise program. For example, a 9-year study of regular runners found that unless they significantly increased their distance or their intensity (ran faster), they gained fat.

So What’s The Solution?

This article will answer that question and give you seven principles for losing body fat with the least amount of struggle.

Principle #1: Combine Cardio With A Healthy Diet That Monitors Portions

Low-intensity cardio works well under a few conditions: First, it’s most useful if your goal is to maintain your body weight, but is less effective for losing body fat. Second, you need to have your nutrition dialed in so that you aren’t overshooting your calories on a regular basis. Few people in the Western world have achieved this.

It’s completely doable to eat within your caloric needs, however, it takes effort and planning: Meals should be designed around high-quality foods that promote satiety and maintain energy levels. Protein (meat, fish, eggs, or legumes), vegetables, and healthy fat should make up the majority of your meals, with refined and packaged foods practically non-existent in your diet.

Principle #2: Include Strength Training

Whether your goal is active fat loss or you just want to maintain your body weight, you’re going to get better body composition results if you include some strength training. Not only does strength training convey an enticing list of health benefits (better brain function, stronger bones, better mobility, less pain, lower inflammation, greater ability to cope with stress), it leads to adaptations in your body that improve your metabolism.

First, you increase lean mass, which ratchets up the energy you burn daily, meaning your caloric needs increase. Second, it makes your cells more sensitive to the hormone insulin so that your body is better able to handle carbohydrates without storing them as body fat.

Third, the intermittent nature of strength training (you lift for a set and then rest) taps into all three energy systems in the body and this leads to a greater metabolic disturbance than low-intensity cardio. The result is that you get a larger afterburn in which your body burns more energy during the 24-hour recovery period.

The bottom line is that whether cardio is a part of your program or not, you want to perform 45 minutes to an hour of strength training 2 to 4 times a week. The following three principles will give you guidelines for designing these workouts.

Principle #3: Pick Total Body Exercises

Some people will tell you to take it easy when you’re trying to lose body fat. But lifting light weights for small muscle movements is like taking the backroads instead of the highway and then getting lost along the way.

By picking exercises that train your whole body (squats, step-ups, rows, presses, lunges), you get stronger faster and you train more muscle tissue at one time, increasing your net energy expenditure. The end result is you burn more calories and have more muscle, resulting in a higher metabolic rate.

Principle #4: Use Supersets & Short Rest Periods

We see it all the time: People sitting on weight machines playing with their phones during rest periods. If your goal is to get in some good phone time while you annoy the other people who want to use those machines, you’re making a good use of your time. But if like most people, you’re in the gym in an effort to reduce body fat, you’re wasting your efforts.

Look, you don’t need to be dripping with sweat and about to pass out when training, but you should be breathing a little hard and making some effort. Rest periods should be active (walking, stretching) and relatively short.

Super sets are a great way to maximize your workouts because they allow you to pair exercises using opposing muscle groups so that one part of your body can rest while the other is working. For example, you could train leg press and hamstring curls, allowing for 60 seconds rest between each set—just enough time to complete the exercise, catch your breath, and get set up for the other lift. Once you complete all your sets, move on to chest press and seated rows, alternating between the two until you complete your sets. Finally, finish up with lunges alternated with overhead press.

Principle #5: Train A High(er) Volume

Volume refers to how many sets and reps you perform for each exercise. Higher volume training is preferable because it causes a significant metabolic disturbance, raising metabolic rate. It also is a greater stimulus for lean tissue development so that you get a net gain in muscle mass over time. Studies show that four sets per exercise is the threshold marker for consistent body composition changes.

Principle #6: Do Intervals

If your goal is to lose body fat, intervals should be a part of your training arsenal. They convey the benefits of strength training (increased lean mass, large afterburn, greater insulin sensitivity) but they also improve fat burning in the body by increasing levels of certain hormones known as the catecholamines that have a potent effect on fat loss.

The thing is that interval training doesn’t need to be terribly difficult. Sure, there are brutally hard protocols utilized by athletes (typically distance runners, soccer and basketball players), but you don’t need to kill yourself to get results. For example, doing 20 minutes of 8 second cycling intervals with 12 seconds active rest has consistently been found to produce 5 to 7 pounds of body fat loss in a series of studies using untrained individuals.

Longer, lower intensity intervals of 3 minutes incline walking alternated with 3 minutes easier walking for a total of 30 minutes has also been found to be effective for reducing body fat in overweight individuals. This sort of protocol is simply a useful variation on LISS cardio: It doesn’t require too much mental effort and can serve as a stress reducer, while giving you additional physiological adaptations not available when you go at a steady, even pace.

Principle #7: Be Consistent

At the end of the day, the single most important factor dictating whether you are able to reduce your body fat is consistency. Changing your body takes time. What you do on a daily basis accumulates to give you the results you want. The more consistent you are with eating and training, the faster you’ll get there.

Once you get to where you want to be, you have to maintain those habits. What does this look like in real life?

Say you want to lose 10 pounds of body fat. Depending on a variety of factors (training and nutrition preferences, genetics, time for training, stress, lifestyle, and so on), this could take 8 to 12 weeks. We’ll go the moderate route and do it over 10 weeks. Here’s what your training should look like:

Two to four days of weight training a week for 1 hour including warm-up.

Two days of interval training for 20 to 30 minutes.

One to two days of LISS such as brisk walking or cycling.

If interval training doesn’t suit you, doing more sessions of LISS is an option. Either way, you want to be mindful of how much you’re eating. Don’t make the mistake of using exercise as an excuse to overeat. This is an all-too common problem that actually has its own term. It’s called “compensation” by scientists and it’s a major reason many people don’t get the physique changes they want from exercise.

Nutrition-wise, we recommend a diet that emphasizes whole foods. Every meal should be designed around high-quality protein, vegetables, and healthy fat. Healthy higher carb foods such as fruit, grains, and starchy vegetables can be included after workouts or as part of your evening meal. Alcohol and “cheat foods” should be kept to a minimum. Refined foods (bread, desserts, chips, candy, pizza, pasta, etc.) and sugar-sweetened beverages should be avoided as much as possible.

Final Words: Hopefully, you understand the physiological factors at play that impact your ability to lose body fat and keep it off. LISS, intervals, strength training, and good nutrition can all be a part of any program geared at improving body composition. It’s not about one method being better than others but about using each one in the most opportune way so that you get the best results with the least struggle possible.