All You Need to Know About Cardio
WHAT is cardio?
WHY is cardio good for me?
WHAT type of cardio should I do?
Do I HAVE to do cardio?
WHEN should I do cardio?
The most common questions I get from new training clients is if they should also be doing cardio to supplement our training sessions.
In this post, I’m going to address some common questions that I get and go deep into all things cardio.
WHAT is Cardio?
Cardio is short for cardiovascular (relating to the heart and blood vessels) training.
It’s basically any form of exercise that increases your heart rate.
When speaking about cardio we normally refer to aerobic cardio (commonly known as Low Intensity Steady State (or LISS)), but there is also anaerobic cardio (commonly known as High Intensity Interval Training (or HIIT)). Aerobic and anaerobic cardio differ because of the intensity, interval and types of muscle fibers used in the performance of each, which I’ll highlight below.
Aerobic Cardio
Aerobic - “Relating to, involving, or requiring free oxygen.”
When performing aerobic exercises, your breathing and heart rate are increased for a sustained period of time. In this state, your body relies on oxygen for energy. Muscles activated by this type of exercise rely on aerobic (oxygen) metabolism to get energy from amino acids (protein), carbohydrates and fatty acids (fats). In this state, you burn fat (because fat requires oxygen in order to be metabolized for energy, the lower the intensity, the more available oxygen your body has and the more fat it burns). Therefore, aerobic exercise sessions will burn more fat, but less calories during the session.
Aerobic cardio relies mostly on slow twitch muscle fibers, which contract slower and at a lower intensity. These fibers are important because they allow you to do endurance work for long periods of time before fatigue sets in. Aerobic workouts increase the size and number of these Type I muscle fibers, which improves endurance performance over the long term.
Examples of aerobic cardio would be swimming, walking, cycling, jogging, long distance running, dancing.
Anaerobic Cardio
Anaerobic - “Relating to, involving, or requiring an absence of free oxygen.”
Performing in an anaerobic state involves quick bursts of energy and is performed at maximum effort for a short period of time. In this state, your body relies on stored energy sources, like glucose (sugar derived from carbs), for energy. It is mainly fueled by the energy sources that are already within the working muscles and does not rely on the inhaled oxygen as an energy source. In this state, the body breaks down glucose stores in the absence of oxygen, leading to a buildup of lactic acid in the muscles (that burning feeling in your muscles).
Anaerobic exercise increases the size and quantity of powerful fast twitch fibers. This shift improves the power and strength of muscles and also increases hypertrophy, or size. Therefore, anaerobic sessions will burn more calories, but less fat during the session.
Post exercise, anaerobic exercise is different than aerobic. This is where EPOC (Excessive Post Exercise Oxygen Consumption) comes in. As the muscles begin to receive oxygen after the workout they start repairing the damaged muscle tissue (happens naturally when building muscle) which takes energy (calories) to do, so you end up burning a few more calories after the session as well (whereas in aerobic you only burn the calories during the session). HOWEVER, EPOC is determined by intensity, not duration, so you need to be going HARD and FAST for this to take place, which is very difficult for most. Research shows that the amount of extra calories is not as significant as once thought.
Examples of anaerobic cardio would be sprinting, jumping, power lifting, high intensity interval training.
Benefits of Cardio (WHY Cardio Is Great to Implement)
Increase in stamina and reduction in fatigue during exercise
Stronger auto-immune system (better resistance to illness)
Helps lower or control blood pressure
Controls blood sugar levels
Decreases potential for osteoporosis
Strengthens your heart muscle
Boosts your mood
Increase metabolism
Many more…
What TYPE of Cardio Should I Do?
This all depends on a couple of factors:
Your current fitness routine
Your current fitness level
How much time you have
What you enjoy most
Both types of cardio are great and in a perfect world you’d be able to implement them both into your workout routine because they individually have such great benefits. If you have less time in the day, HIIT might be better for you. If you enjoy longer and slightly easier formats of exercise, LISS might be better for you. Do you like more of a challenge? Do you want something that’s a bit more entertaining and manageable? Ultimately, the best workout is the one you’ll do. For example, for weight loss, one study showed that although the participants that were asked to do HIIT saw “quicker” results, over the long term the participants that were asked to do LISS were able to actually sustain their results for much longer because they experienced more exercise adherence (ability to stick to a routine) because LISS is easier and more enjoyable to do for most. So, ultimately, the one you’ll do consistency and enjoy is the one for you.
Do I HAVE to do Cardio?
You don’t HAVE to do anything :)
That being said, there are many, many great benefits to cardiovascular training, and the best part is, there are so many different ways to do cardio. We get stuck on cardio in its most basic form: elliptical, cycling, walking, running, etc., that we forget about all the other different forms of cardio: swimming, dancing, hiking, etc. Even so, it doesn’t need to be as dull or as complicated as we make it seem, talking with a friend, listening to a podcast or audiobook, exploring a new part of the city, are all different ways you can actually use cardio to change up your day.
If you’re new to exercise, you might want to start with aerobic exercises to build up endurance. If you’ve been exercising a long time you can add anaerobic workouts into your routine to change it up and try something new.
So no, you don’t HAVE to do cardio if you already move your body in other ways, but given it’s so good for our health, I do highly recommend it.
“The American Heart Association recommends healthy adults get at least 30 minutes of moderate-intensity aerobic exercise at least 5 days a week, or at least 25 minutes of vigorous aerobic activity 3 days a week. Perform anaerobic exercise like HIIT workouts no more than two or three days each week, always allowing for at least one full day of recovery in-between.”
WHEN Should I Do Cardio?
This will depend with your unique schedule. There really is no secret sauce as to WHAT time of the day is best. The best time of the day is the day you’ll be able to do it stress free. For some, that’s in the morning. For some, that’s during their lunch break. For some, that’s after work. Instead of trying to figure out the “best time of the day” to do it, figure out the “best time of the day” for YOU to do it. Again, all of this is in vain if it doesn’t work for YOU and isn’t sustainable for YOU.
Cardio Duration & Intensity.
Duration
Aerobic (LISS) exercises typically range from 30-60min. If that seems like a lot, start with something smaller, like 10-15min, and just work on adding more time (like an additional 10min) when you can and build from there. No need to rush or scare yourself off. Ideally, you’re doing at least 30min 5 days a week.
Anaerobic (HIIT) exercises typically range from 15-20min as they are more vigorous in nature and cannot be sustained. Ideally, you’re doing 15-20min 2-3 days a week, however, more than that is not recommended for most and you should allow at least one full recovery day in between.
Intensity
My favorite two ways (and the ones that are accessible to everyone) to measure your workout intensity are Heart Rate and Rate of Perceived Exertion.
Heart rate is a bit more complicated, so I’ll start there.
First, you’ll find your estimated Max HR by subtraction 220 by your age.
So, if I’m 30, my Max HR would be 190 (220 - 30).
From there, you estimate what percentage range you should be in for the given exercise.
If I’m doing LISS, I’m looking for 60-75% of my Max HR which would be 114-143.
If I’m doing HIIT, I’m looking for 85-95% of my Max HR which would be 162-180.
During exercise, check your Heart Rate to make sure it’s within that level, if it’s higher, slow it down, if it’s slower, speed it up.
If you have a fitness tracker (Apple Watch, FitBit, etc.) you can use that (they’re fairly accurate).
You can also check your pulse by finding your carotid artery (a bit more complicated, but very accurate).
Heart Rate is great, but for most, a little too much to have to think about, which is why I really like Rate of Perceived Exertion (RPE). RPE might feel difficult to choose at first, but as you gain more experience it’ll get easier, I also love how much it requires you to tune into your body.
A good guide to measure your RPE is through your breathing and the talk test on a scale of 1-10.
0 = No exertion (sitting on the couch watching TV)
1 = Very light exertion (doing chores like washing the dishes)
2 = Light exertion (walking through the mall)
3 = Moderate exertion (brisk walk) (LISS Zone)
4 = Starting to put in some cognizant effort (LISS Zone)
5 = Starting to feel the cognizant effort being put in (fast walk) (LISS Zone)
6 = Getting intense (jogging - gets the heart-pumping and breathing is fast)
7 = Hard, but still sustainable (fast run) (HIIT Zone)
8 = Very hard, but still somewhat sustainable (HIIT Zone)
9 = Extremely hard, very difficult to sustain (HIIT Zone)
10 = Can only sustain this effort for a few seconds (an all-out sprint) (HIIT Zone)
As always, try not to stress about it too much. We’re always looking for the “best way to do x” or the “best time to do y” and we overwhelm ourselves so much that we don’t start or we get intimidated and think we can’t do it. Not only have we still not exercised, but now we’re even more stressed out about it. Exercise is supposed to be enjoyable. My biggest tip…. If you find you’re overwhelmed, and you don’t know where to start, just think of the first form of exercise that pops up in your mind and sounds like fun, and start there. It matters less to me how you move your body, as long as you’re moving your body. If you’re really overwhelmed and need help starting your fitness journey, feel free to reach out to me :) That’s what I do after all.
References:
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5329739/…
https://pubmed.ncbi.nlm.nih.gov/21904237/…
https://www.acefitness.org/education-and-resources…
https://pubmed.ncbi.nlm.nih.gov/14599232/…
https://pubmed.ncbi.nlm.nih.gov/17101527/…
https://breakingmuscle.com/fitness/the-myth-of-interval-training-and-epoc/…
If you’re looking for a safe space where you can learn how to let go of dieting for good, enjoy food without guilt, and turn exercise into something you love to do rather than something you “have” to do, submit a client application to get in contact with me! I work with clients virtually all over the world helping those who are frustrated with dieting and want to change their relationship with food and themselves.
Hi, I’m Azul Corajoria, an Integrative Health Coach, Personal Trainer & Yoga Instructor. I support my clients in making step-by-step changes so that they can live a healthy and balanced life. By recognizing the interdependent roles of mindset, nutrition, and movement I educate and hold my clients accountable for achieving their health goals through lifestyle and behavior adjustments with an emphasis on self-care. Together, we navigate the contradictory world of nutrition through intuitive eating, practice mindful movement, and implement small mindset and lifestyle shifts that empower them to be their best selves in the easiest way possible.
