Cardio for Heart Health, not Fat Loss

    Cardio sucks. Sorry to all the cardio bunnies out there who love it, but seriously cardio sucks. I know others feel the same way about it, and like them I used to believe cardio was this activity you did to get your heart rate up, breathing heavily, dripping sweat, and looking at your time to see if you are done. What I have come to learn is that there are different levels of cardio and different tools we can use to do cardio. When somebody says cardio, a lot of us automatically think running, me included. That is a big reason I stayed away from cardio, I hate running distance. Now I mentioned different levels of cardio, let’s go into that a bit. You can differentiate cardio based on its intensity, or how hard you are going. On one spectrum is High Intensity Interval Training, also well known as HIIT. The other side of the cardio spectrum is Low Intensity Steady State, also known as LISS cardio. Then you have forms of cardio that go in between these two different cardio modalities. I will not go too deep in the different cardio types because I want to focus on a specific type of cardio for our health and wellbeing. Just know that HIIT is very intense and demanding on the body, beginners should not be attempting HIIT training. This type of cardio should be done 2x/week max with plenty of time in between to rest. What I want to go deeper on is LISS, particularly zone 2 cardio and all its benefits. 

What is Zone 2 Cardio? 

    I mentioned that I hate running, it just doesn’t feel good to me, luckily you do not need to run for cardio. LISS is a form of cardio where it is low intensity and can be done for long periods of time. I want to be more specific with LISS and that is zone 2 cardio. Zone 2 cardio is an exercise that you do at a pace that allows you to sustain a certain heart rate that is below the aerobic threshold for up to 30 minutes or more. Aerobic Threshold is the point when the body builds up lactic acid due to the body switching energy sources. Without going scientific, the body can use different energy sources to complete a task. When you do certain activities the body can use sugars as energy, or fats as energy and different heart rate ranges can influence the type of energy you are using. I would like to be very clear here, just because the body can use fat as a energy source it does not mean you are losing fat. Read that again because you must be in a calorie deficit to lose fat. I have explained this in my article about fat loss if you want to know more about losing fat. Just know that the body is able to use carbohydrates and fat as an energy source, and during zone 2 cardio, the body primarily uses fat from the body to fuel this activity. 

    How do I know if I’m doing zone 2 cardio? There are a few ways you can determine if you are in zone 2 or not. A simple way to measure is if you can easily hold a conversation while you do your cardio. If you are able to read your heart rate you will be able to know without guessing. 

  • First you have to know your max heart rate. Use this equation: 208-(0.7x age)

Ex. 208-(.7x 30) = 208-21 = 187

  • Now that you know your max heart rate, you want to know your minimum and maximum heart rate for zone 2. To be in zone 2 cardio you have to be in between 60%-70% of your max heart rate. Ex. 60%=0.6 x 187= 112.2 and 70%=0.7x 187= 130.9. So my zone 2 range is 112-130 heart beats/ minute.

Knowing the rane in the beginning is great because now I know what to look for during my cardio session. As you build your aerobic capacity you might find that these numbers will be higher. You might have to have a quicker pace without feeling as tired, and that’s a good thing. 

So what kind of activities can I do for zone 2 cardio? That’s a great question, and the simple answer is anything you want as long as it keeps you that heart rate range, or able to hold a conversation without trouble. Some ideas you can do is go for a walk, hike, bike, swimming, or jog. The goal is pick something that you enjoy, be consistent with and again stay in that heart rate range with no issues. You want to be able to perform this cardio 2-3x/week for 30-60 minutes per session. 

Benefits of Zone 2 Cardio

    Why should I be doing zone 2 cardio and not other forms like HIIT? First I want to mention that doing cardio in zone 2 is more sustainable than HIIT and can easily be done everyday without overtraining. I said this earlier, HIIT is very demanding on the body, if you were to do it everyday, eventually your body will break down. Your risk of injury dramatically increases and you can actually see a decline of your health including inflammation in the joints. One of the great benefits of zone 2 cardio is how restorative it can be for the body. Here is a list of benefits of zone 2:

  • Increases overall available energy
  • Improves metabolic flexibility
  • Lowers resting heart rate
  • Decreases blood pressure
  • Improves insulin resistance
  • Builds aerobic base, foundation of aerobic work
  • Increases energy expenditure
  • Sustainable for long term consistency
  • Restorative for the body
  • Mental health 

    Like I said earlier, zone 2 is restorative meaning it helps you just feel good while you’re moving. The benefits for your heart are amazing, it will decrease your blood pressure and lowers your resting heart rate. This is because your heart does not have to work as hard. It becomes very efficient with its ability to pump more blood through your body. A stronger heart will be able to fill up more with blood and have the capability/strength to pump more blood, meaning less heart beats to do the same amount of work. This puts less strain on the heart, reducing your risk of cardiovascular disease. You are building aerobic efficiency, meaning that you can increase your pace of work without effort. Whatever the task is, you have the ability to work more without fatigue. Working in the yard for example, you can work a little more without the need for breaks, allowing you to put in more work in less time spent. 

    I am really hammering on the health benefits of zone 2 cardio, because that is what the focus should be. Yes, cardio will burn calories and can aid in fat loss when you are in a calorie deficit. But, the goal is not to burn calories. You will not burn a whole lot of calories from zone 2 cardio. The goal of any exercise is not to burn calories. One reason is because we have no way to accurately measure how many calories you spend during movement. The watch that tells you you burn this many calories is not accurate. Many many studies have shown how inaccurate they are, and they mostly exaggerate how many calories you burn. The goal of exercise is about making the body adapt from a specific stimulus. That adaptation is what we are looking for with exercise, and that can look like an increase of muscle mass, strength, speed, endurance, power, mobility, and more. You can use exercise to help increase your mobility and strength so you can move and feel better. Exercise can be used to help improve your health so there can be multiple adaptations going on in the body. In this instance talking about zone 2 cardio, the adaptation is heart health, getting our heart to work better. Side effects can be feeling better, moving better, having more energy to move more, and losing fat a little easier. We were taught this idea of using exercise to burn calories, and this an unhealthy approach and setting yourself up for failure. Change your mindset on exercise to help you be healthy, move and feel better, and be able to train to perform a specific task.

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