Cardio For Weight Loss, Everything You Need To Know

By JC Deen



Is cardio the best form of exercise for weight loss? The answer will largely depend on your goals, wants, and needs, but we’ll cover every possible question you have to make an informed decision.

It’s common to think that cardio automatically equals fat loss, but it’s not the case at all. In fact, while doing some extra cardio can be helpful, it can also hurt our ability to recover from weight training and can even make us hungrier. And being more hungry causes us to eat more, which will stall fat loss efforts in a hurry.

There are two different ways of doing cardio, so let’s quickly cover those.

Types of Cardio: Aerobic and Anaerobic

To understand what cardiovascular training is, you should know the two types.

Aerobic = Requires Oxygen

When you imagine aerobic activity, think long duration or distance. This is your traditional type of cardio exercise. Most people doing this type of exercise are biking, jogging, rowing, running, hiking, or using the stair-stepper or elliptical machines. This type of cardio can be done for extended periods of time without much need for a rest.

Any type of activity you can sustain for longer than about 45-60 seconds could be considered aerobic in nature. You’ll work up a sweat, muscles will be warm, and your heart rate will increase and remain elevated during exercise.

Aerobic exercise typically relies on fat for fuel at these lower intensities.

Anaerobic = Doesn’t Require Oxygen

When you imagine anaerobic activity, think quick, short bursts of high-intensity activity. This type of training is for experienced exercisers due to the level of intensity it requires. Most people doing this type of cardio are sprinting, lifting weights, or doing high-intensity movements to improve their speed or quickness, such as jumping or skipping.

A popular method of anaerobic training is known as high-intensity interval training (HIIT), where you exercise at your maximum level of ability, such as sprinting full speed up a hill or doing a super-set of squats and push-ups with minimal rest between sets.

Anaerobic exercise relies on ATP, which comes from glucose that’s made from the carbohydrates stored in your muscle cells, called glycogen.

What’s The Best Cardio For Weight Loss?

In my opinion, the best cardio for weight loss must be in line with the following guidelines:

  • You’re able to recover from it
  • It’s something you can do safely, over the long-term

Just like weight training, no cardio plan is going to benefit you if you can’t stick to it. High-intensity interval training (HIIT) is amazing for fat loss, but it is similar to weight training in that it requires a longer recovery period than something like walking.

So depending on your personal goals, the type of cardio will vary. However, for most people, I think a good dose of regular walking each week is a good place to start. Check out walking for weight loss to learn more about how walking can help you lose fat.

HIIT is a great option for burning fat but it poses a risk for injury if you’re inexperienced, and if you add it on top of your weekly weight training, it can limit your ability to recover fully, which might result in strength and muscle loss over time.

So if you decide to use HIIT in your program, it’s best to fit it in on a day you’re training, so you’re able to maximize your rest and recovery days.

If you wanted to incorporate HIIT into your exercise plan, you would do your HIIT session on a lower body training day right after your workout. This way you can still reap the benefits of this intense training without it cutting into your ability to recovery on off days.

How To Assess If HIIT Cardio Training Is For You

To determine if intense cardio training will help your weight loss efforts, take a quick look at the cost/benefit ratio:

The Benefits

  • Efficient: Burns a high amount of calories in a short time period.
  • Good for muscle maintenance: similar to weight training.

The Costs

  • Risk of injury: it’s easier to injure yourself with intense sprinting and other forms of interval training.
  • Hard to recover from: if you do too much high-intensity work in a short period of time, it’s hard to recover adequately from workout to workout.

At the end of the day, you have to make a decision as to whether or not intense cardio training is a good fit for you on a personal level.

Why Cardio Works For Weight Loss

To put simply, cardio training burns calories. The more active you are during the day, the higher your metabolic rate. Cardio is a form of activity, just like weight training, playing sports, or dancing. All of these activities will require energy (from calories), and as a result, the exercise helps you lose weight.

Remember, you must be in a caloric deficit in order to lose weight with cardio (or any other activity). If you don’t manage your total caloric intake, you will simply maintain your weight despite lots of cardio and exercise.

Is Cardio Essential For Fat Loss?

In one word: no.

You don’t have to use cardio to burn extra calories which will lead to fat loss. If you enjoy weight training, or some other form of activity more than traditional cardio, you can still manage to lose fat without boring cardio routines.

Cardio is ONLY a tool. Some people lose fat only weight training 3-6 times per week and managing their diet. Others use a combination of cardio and weight training. Some utilize only cardio as their preferred method of exercise.

At the end of the day, for fat loss to happen, all that matters is the following:

  • You create a caloric deficit through your diet and/or exercise.
  • You do some form of resistance training if you want to maintain muscle mass.
  • You have enough patience to let progress happen naturally over time.

How Much Cardio For Weight Loss?

There are no hard rules for how much cardio you need to do for fat loss to happen, but for my coaching clients, what I often recommend is 2-4 weight training sessions per week and some light activity in the form of brisk walking, hiking, biking, swimming, etc., on their off days 2-3 days per week.

cardio for weight loss
Try getting outdoors for a hike

At the end of the day, no cardio is required, but adding in some form of movement, even if it’s just walking, can help you burn more calories and lose fat more efficiently and quickly.

Is Fasted Cardio Better Than Fed Cardio?

No. See my article (coming up soon) on fasted cardio and why the claimed benefits don’t matter as much as we thought.

Do I Need To Be In The Fat Burning Zone?

There’s a so-called fat burning zone and many people for the longest time would make a recommendation to perform cardio in the ‘Fat Burning Zone’ in order to be most effective.

And while it’s not completely wrong, it sort of misses the big picture about how we actually burn fat over time. At any given moment during rest, your body is burning fat for energy. Even during movements like walking, biking, and general activities such as gardening, walking up the stairs, or getting your mail, you’re burning fat.

It’s only when we do high-intensity activities like weight training or sprinting that we burn glycogen (which is stored carbohydrates in our muscle cells) specifically.

The fat burning zone tends to be somewhere within 50-70% of your maximum heart rate (MHR), meaning that you should aim to keep your heart rate at a certain level. And the way you’d calculate this is by subtracting your age from 220 and then multiplying your number, which is your estimated maximum heart rate, by .5 – .7 for the range.

For example, let’s say you’re 25 years old. 220 – 25 = 195. 195 = MHR.

50% of 195 = 97.5

70% of 195 = 136.5

So for the sake of this example, the so-called “fat burning” zone for a 25-year-old person would be to achieve a heart rate of somewhere between 97 and 136 beats per minute.

But at the end of the day, this doesn’t matter. At all. Seriously. This is not worth worrying about because our bodies burn fat all the time.

What’s most important is the caloric deficit for fat loss. Period. End of story. Sure. macros matter, counting macros properly matters, and weight training helps you maintain muscle, but a caloric deficit will take care of fat loss.

So don’t worry about trying to maintain a certain heart rate, just focus on getting your training sessions and cardio sessions completed. It’s not worth tracking your heart rate and trying to stay within a certain range.

Note: just by talking a walk, or training with weights, you’ll find yourself somewhere between the 50-70% fat burning range for most of that activity.

Another not-so-important idea is the so-called fat burning foods. There are, literally, no foods that burn fat. It’s the act of eating less food that actually burns body fat.

cardio for weight loss
Walking for weight loss is a great method of cardio.

Why You Should Avoid Overdoing Cardio

Remember, with a goal of fat loss, cardio training is only a tool. If it makes sense to go on an extra long walk every morning to burn some extra calories, do it. But don’t overextend yourself with extra running, biking, or intervals if it doesn’t fit well into your current training program.

Here are a few reasons why you should avoid overdoing cardio training.

  1. It’s not sustainable. If you try to do extra cardio during the week in order to burn off some calories to make your fat loss progress happen more quickly, it’s only a matter of time that you have to cut off the extra sessions. The same goes for weight training. If you plan to do a 6-day-per-week program, but can only realistically fit in 4 training sessions per week, it’s only a matter of time before you aren’t able to commit to the sessions and feel like a failure.
  2. It makes you more prone to injury. Lots of cardio sessions (outside of light walking or biking), can cause more wear and tear on your body, inhibit recovery, and cause you to be more likely to develop an injury either from overuse, or having an accident that causes an immediate injury (such as spraining an ankle or knee, or pulling a muscle, etc).
  3. Lots of cardio (and activity in general) raises stress hormones. You’ve likely heard of a hormone called cortisol. You’ve also likely heard about how bad it is, but in reality, hormones are neither bad or good. We only run into problems when they get out of balance. It’s been shown that too much high-intensity exercise (weight training, sprinting, long runs) can cause a spike in cortisol if done too frequently. Studies have shown that lower intensity activity (like walking) can help reduce cortisol levels, so if you’re already training hard 3-4 days per week, doing some extra walking would be your best variation of cardio.

Don’t Use It For A Quick-Fix

It’s easy to get caught up in the “I need results yesterday” mindset, but it’s totally unrealistic and will lead to burnout, and a lack of progress. Oftentimes I’ve seen people ramp up their output going from zero cardio to 5 runs a week on top of their weight training. This is not the way to go.

Cardio is only a tool to be used when necessary. And if you don’t particularly like long bouts of cardio such as running or biking, then you will want to consider something you can easily do and stick to.

Remember that training and cardio are means to an end, but they’re also a means of maintenance. There will be times when you need to do more and times when you need to do less. At the end of the day, you must ask yourself: “is what I’m doing sustainable, and realistic over the long term?”

If your answer is no, it’s time to rethink the approach.

Can You Still Lose Weight Without Cardio?

Finally, yes. You can lose weight without running, or jogging, or high-intensity intervals. What matters most is your ability to create a caloric deficit through nutrition and your preferred method of activity (be it cardio or weights or any other activity you enjoy).

Many of my clients lose weight without specific cardio, other than some walking on their off days.

JC Deen is a nationally published fitness coach and writer from Nashville, TN. Currently living in the blistering Northeast. Follow me on X/Twitter