In this episode, we shall talk about cardio or cardiovascular exercise. We’ll cover the different types of cardio, the most effective cardio that you can do, the role of cardio in fat loss plus any other questions that you may have ever had regarding cardio. So put on your seatbelts and let’s dive in.
What is cardio? 🥵
Your breathing gets faster and deeper. You heart feels like it is going to burst out of your chest. And you sweat like you have just stepped out of a sauna at volcanic temperatures.
If you are an avid runner, you would relate to this feeling. These bodily reactions are a result of you moving the large muscles in your arms and legs over a sustained period of time. As you push your muscles to perform a sustained activity, they require an increasing amount of energy to carry out the activity. This causes the need for extra oxygen which is provided by your heart, which leads to the rapid thumping sensation in your chest. This form of activity which heavily involves oxygen expenditure is called aerobic exercise or cardio.
So in short, any vigorous activity that increases your heart rate and your respiration while using large muscle groups of your body repetitively and rhythmically can be classified as cardio.
What are the types of cardio? 🤔
Broadly, you may have come across two popular forms of cardio: High Intensity Interval Training or HIIT, and Low Intensity Steady State or LISS.
All cardiovascular exercise can be categorised into these two broad categories. There seems to be a growing popularity of HIIT based workouts in recent times. And people mostly seem to believe that HIIT is the most effective form of cardio.
But is it really? Let’s find out.
High Intensity Interval Training or HIIT involves short bursts with high effort followed by low effort rest intervals. So, if you do HIIT while running, you would do high effort sprinting for 15 seconds followed by 10 seconds of light jogging and repeat this throughout your workout. HIIT is intense, fast and brutal. Also it is extremely high stress for the body.
LISS or Low Intensity Steady State is the exact opposite. If you do LISS while running, you would run at a steady pace keeping your heart rate sufficiently high but you will carry this out for a longer time period. So while a HIIT workout will take you about 15-20 minutes to complete, a LISS session can last as long as 60 minutes.
The popular notion that HIIT leads to better results is false. There is a term called EPOC or Post-exercise Oxygen Consumption also known as the Afterburn Effect. It sounds really fancy…very scientific…and you’ll see this thrown around by fitness influencers on social media all the time.
The idea is that the HIIT allows you to have an afterburn effect that will turn your body into a fat burning machine. And you will keep burning fat even after you are done with your workout.
Is this correct? Somewhat, yes.
But, the amount of fat you will burn from this so-called afterburn effect is so insignificant that it makes no difference at all. Its effect would be similar to taking a drop of fat from the entire ocean of fat in your body. Neglible.
So, does this mean that LISS is better than HIIT? No. If you compare both forms of cardio neither is significantly better than the other in terms of the results they offer.
If your goal is fat loss, you can do either of them and get pretty good results. The only factor that you should consider while making your choice is your own personal preference.
When should you pick HIIT? 🔥
If you love intense training that makes you feel like you are really pushing past all your limits, HIIT is the way to go.
HIIT workouts are also very time-efficient and barely take 15 minutes to get done. Some styles of HIIT like Tabata are designed just for 4 minutes. I however wouldn’t recommend going to such extremes as most people can’t keep up with the intensity of training styles like Tabata.
So you might just end up doing a 4 minute workout which was not intense enough and served no purpose.
When should you pick LISS? 🚶
If you are someone like me who absolutely hates feeling like you are dying everytime you do some cardio, just go for LISS.
It will keep you at a comfortable pace. It would be way less stressful for your body and you will get the same results.
But it will however take more time. Most LISS workouts usually last for 45 minutes to an hour. So you must be willing to make that kind of time commitment if you want a low intensity variant.
Which type of activity should you pick for your cardio workouts? 💯
Another thing that is to be considered while picking your cardio option is the level of impact it has on your body. Most activities can be classified as high impact, low impact or no impact.
High impact cardio is any activity that requires you to have both feet off the ground at some point. It includes activities like jumping rope, running and high impact aerobic dance.
In low impact activities, at least one foot remains on the ground at all times. It includes activities like walking, hiking and low impact aerobic dance.
No impact or zero impact cardio involves any cardio that is performed in water. So activities like swimming and water aerobics would be considered as no-impact cardio. Even cycling is considered as no-impact cardio as the cycle frame supports your body throughout the movement.
High impact cardio is usually fast paced and very fun for most people. It makes your heart race and makes you feel like you are really putting in some effort. However if you have joint issues or suffer from conditions like arthritis, you should avoid high impact activities.
Personally, I have really flat feet. So running for a long time causes me to get shin splints, my knees start to ache and it also makes my back feel weird. But I have a lot of friends who love running and many of them have run marathons. I could do that as well but it would put my body through a lot of unnecessary stress. And it could also lead to chronic injuries.
So if you have back issues or joint issues and you still wish to perform cardio, pick low impact or no impact activities. Go for long walks, take up swimming or join a spinning class.
How much cardio do you need? 📈
Now that we know all the different variations of cardio, how much cardio do you actually need? The answer to this question depends on your goals.
If your goal is to build cardiovascular endurance, then cardio would be your primary form of training. This is how most marathoners and endurance athletes train. However, if your goal is to lose body fat and to look good, technically you can achieve your goals with zero cardio.
That’s right. Zero cardio.
But since your heart is a mostly made up of muscle, it does make sense to train it just like other muscles in your body. So incorporating a minimum amount of cardio into your training is always a good thing.
This can be easily achieved through two short weekly cardio sessions. It doesn’t even have to be inside a gym. You could take your dog for a long brisk walk. You could go hiking with your friends. Or you could cycle to your workplace on alternate days. There are so many easy ways to do this. It doesn’t have to be boring like running endlessly on a treadmill.
Is there such a thing as ‘too much cardio’? 😖
Also, doing too much of cardio can actually be worse than doing no cardio at all. Research shows that endurance athletes are at a higher risk of heart dysfunction than the general public.
Studies also show that marathoners develop more arterial plaque than sedentary non-runners, which increases the risk of stroke and dementia.
So it is not completely inaccurate to say that doing too much cardio might actually kill you. This is true for any exercise activity in general. But for cardio specifically, more definitely isn’t better.
You should do only as much cardio as it takes to achieve your goals. If your goal is to lose weight and lose fat, it is much easier to do so by fixing your diet than through cardio. Losing weight requires you to eat lesser calories than you burn and this is much easier to do by fixing your food habits than by doing excessive amounts of exercise.
In fact people who focus too much on exercise to burn fat have been shown to get even fatter than when they started because of compensatory behaviours they develop. This happens because when after every exercise session, you feel like you have earned a treat and get a cheat meal, you end up consuming far more calories than you actually burnt. Exercise in general doesn’t burn a lot of calories.
You would hear a lot of people saying absolutely non-sensical things like “It’s okay. Today is my cheat day. Tomorrow I have a cardio session. So, I’ll burn this off.” Or, “It’s alright. Just eat this piece of cake. You can burn it off tomorrow.”
Well, guess what? An usual meal for most people when they go out with friends can range anywhere between 700 and 1500 calories. To burn all of that you will have to at least do 1 hour of High Intensity Interval Training which is physically impossible for even top athletes. Or run at least 10kms the next day which will burn around 600 calories on average.
If you enjoy that kind of self-torture, sure, go for it. But my point here is that there is a much much easier way to lose weight if that is your primary goal.
A 15 minute HIIT session may end up burning 200 calories on average. This is the amount that is there in a small chocolate bar. Or a slice of pizza. If you just cut out one snack from your regular diet, you would achieve similar results to that of doing a HIIT session everyday.
Just because you are sweating and working hard doesn’t mean what you’re doing is effective. If you have been doing cardio for a long time and are still not losing weight or worse, you are actually gaining weight, this is probably the reason why.
Cardio is not a magic bullet to lose weight. The main purpose of cardio is to increase cardiovascular fitness, not to burn calories.
Cardio also has been shown to reduce NEAT or Non-exercise Activity Thermogenesis. This is just a fancy term for all the small movements that you do on a regular basis like moving your arms and legs, walking to the kitchen, fidgetting with your fingers and so on.
Any movement with your body which is not exercise counts as NEAT. NEAT is actually a very important component of calorie burnng. So even when you think you are not doing anything, the consant fidgetting with your legs or making hand gestures while talking: all of these small things burn calories and they add up throughout the day.
Doing too much cardio can reduce NEAT levels according to research. This means that although you burn some amount of calories during your cardio session, you have reduced the calorie burning that happened through regular small movements. Eventually this may cancel out any weight loss benefits that cardio would have had for your body.
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What is the appropriate prescription for cardio? ✅
If your primary goal is to build cardiovascular endurance and this can be the case if you are a marathon runner, then you definitely must make cardio a priority. And this shouldn’t be just any cardio. There are specific plans for runners which focus on improving your cardiovascular capacity and performance. You must follow a structured program like that.
If your goal is fat loss, cardio should definitely not be your primary tool. The majority of fat loss should come from your diet. You cannot out train a bad diet.
Excessive cardio in fact can hinder your fat loss process by inducing compensatory behaviours like excessive food consumption and reduction of Non-exercise Activity Thermogenesis or NEAT.
Cardio like HIIT is also high stress which challenges your body’s adaptive mechanisms. This means that if you do too much HIIT style training, you have less capacity to recover from other beneficial training methods like weight training.
The quickest way to ruin your body’s appearance would be to not weight train at all, have a poor diet and do a lot of cardio. If you follow this recipe, you will 100% have further struggles with getting in shape down the line.
To wrap it up, unless you are an endurance athlete, it doesn’t make sense to make cardio a top priority in your training program.
As a rule of thumb, if your primary goal is to look good and build a great looking physique, your total cardio for the week should take no more than half the time you spend lifting weights. So if you lift weights for 6 hours a week, your cardio sessions in total should be lesser than 3 hours at most.
Only if it becomes too difficult to reduce calories from diet alone, which can happen if you are a smaller sized woman, then adding in more cardio can be beneficial as it will allow you to eat more food.
Closing thoughts ⬇️
Cardio is a high stress activity which doesn’t give proportionate benefits for fat loss goals. It also induces mental fatigue, increases appetite and affects your recovery from weight training.
You should therefore use this tool very sparingly and not overuse it like a lot of people do, because that can lead to damaging results for your body.
How do you incorporate cardio into your training program? Let me know.
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