Why cardio matters for your heart and overall wellness

I’m sure at this moment in our history there are very few people on Earth who haven’t heard the word “cardio” in some context. And many of us practice “doing cardio” as a way to exercise. Let’s figure out what this word actually means in terms of physical activity and why is it essential for our health.

The word “cardio” (from Greek καρδίᾱ kardia, 'heart’) usually refers to one of the three concepts.

Cardiovascular system - the system of the body that includes heart, blood vessels and blood and is responsible for transferring oxygen, nutrients and hormones to cells and removing waste products.

Cardiovascular fitness - is a component of physical fitness, which refers to a body’s ability to deliver oxygen to the working muscles, and rid of metabolic waste.

And the most often the word cardio is used to refer to aerobic exercise - type of physical activity performed by large muscle groups at light-to-moderate intensity for extended periods of time.

Heart is a muscle. But unlike any other muscle in human body, heart never stops working. From week 5 of pregnancy and to the very last breath this muscle is pumping blood. The moment it stops - we are in trouble. So it is quite important to keep the heart in a good shape. 

But besides the heart, in order to deliver oxygen to the cells, we also need blood vessels, blood itself and lungs to pull the oxygen from the outside world. All these organs get supported through regular aerobic exercise. So, what happens when we do our cardio?

• Heart becomes bigger and stronger, it can pump more blood in one stroke, meaning it needs fewer contractions to supply cells with nutrients. Also it means lower resting heart rate. In the long run it means that the heart will have more years to beat for us without that much wear and tear.

• The body recognizes the demand your muscles put on oxygen delivery system, and approves building more capillaries: both in lungs and working muscles, thus providing higher capacity for transporting oxygen.

• Muscles themselves learn to become more efficient oxygen users. Growing more mitochondria helps muscles work longer without fatigue. More myoglobin and oxidative enzymes improve how muscles process oxygen.

How to know if your cardio fitness is good? 

There are multiple ways to assess the level of cardio fitness from the ones you can do yourself to more complex for which you’ll need a doctor and a lab.

One way to tell that your cardio is generally okay is to be able to comply with Physical Activity guidelines for Americans. According to their recommendations, adults should be capable of performing at least 150 minutes of moderate intensity aerobic activity per week. The more - the better, but if you are not there yet - don’t worry. It’s just a number to give you an idea of what to strive for.

For more detailed results, a trainer at the gym can perform standard tests, such as 1 mile walk test, or YMCA 3-minute STEP test. The 1-mile walk test involves walking a mile as quickly as possible and measuring your heart rate afterward. The YMCA 3-minute step test measures your heart rate after stepping up and down on a platform for three minutes. These tests show how your heart reacts to the stress and how quickly it returns to its normal state after the stressor is gone. 

For more complicated cases or if you need some degree of precision, there are stress tests that a cardiologist can do. They make a person perform a specific exercises (usually walking/running on a treadmill with various incline) while reading their EKG and other metrics. This test should only be performed by a doctor.

Here are some numbers to remember regarding heart health:

• 60 to 100 bpm (beats per minute) - normal range for resting heart rate for adults.

• 220 minus age - maximum heart rate the individual shouldn’t go over while exercising.

• 50-85% of your maximum heart rate – Target heart rate zone for most people during exercise. This is the range where you’ll get the most benefit for cardiovascular fitness. You can calculate this by using your maximum heart rate (220 minus age) and multiplying by 0.5 to 0.85.

• < 120/80 mmHg – Normal blood pressure. This is the ideal target for adults to maintain healthy heart function.

  
  

What is the best cardio routine for weight loss?

This is a tough question, and the short answer is none. Because despite a popular misconception, aerobic exercise is not the most efficient way to lose weight. While cardio burns calories, the moment you step off the treadmill, energy expenditure returns to its resting levels. Moreover, the body adapts quickly, making long-term fat loss more dependent on nutrition and muscle mass. 

Interesting fact. Resistance training burns less calories during the actual session - approximately 300 kcal for an hour of weight lifting vs 500 kcal for an hour of cardio. But unlike aerobic workouts, after you are done with a strength workout, your body keeps burning energy for at least 72 hours to restore glycogen you have used while exercising and rebuild damaged muscle tissues. And resynthesis of protein is one of the most energy-demanding processes in the body. So, after resistance training session the body burns fat even when you are sleeping.

So, instead of focusing on cardio for weight loss, think of it as a way to improve endurance, heart health, and overall energy levels. 

But remember, both cardio and strength training complement each other for overall wellness. Cardio keeps your heart healthy, while strength training builds muscle and boosts metabolism.

How to train cardio? 

The options for cardio training are truly endless. The main thing to look for is to ensure that the activity involves major muscle groups, is performed for prolonged periods of time (5 minutes is fine, too! Just more than a couple seconds you need for a single-repetition lift) and on low-to-moderate intensity. It means that you still can somewhat talk while moving your body.

Here are some examples of activities that count as cardio (the list is not even close to complete!):

• Walking/hiking

• Jogging/running

• Cycling

• Rowing

• Dancing

• Swimming laps

• Climbing stairs

• Participating in a group class, such as step aerobics, spinning, Zumba - you name it!

• Any team sports, honestly… Soccer, volleyball, squash, tennis

• Rock climbing on easy, but long routs

Something to Try

Want to improve your cardio fitness? 

The first thing to do is to walk more. 

• Park further away from your work, grocery store, restaurant, etc.

• Take your calls outside or just pace around the room while on the phone.

• Take stairs instead of an elevator

• Try inviting your friends for a walk or hike instead of coffee. Or take your coffee out and still go for a walk!

• Get a dog (just kidding. But really!)

If you are ready to move on to something more intentional or/and intense, here are some things to consider:

• Pick an activity that you genuinely ENJOY. As mentioned above, aerobic exercise are supposed to be performed for extended periods of time, and there is no sense in spending this time suffering.

• Start small. Block time in your calendar dedicated for your workout and consider it a high priority to-do

• Switch anytime

Worth checking out

• Body Groove; https://www.bodygroove.com/ 

• Guidelines for Americans: https://odphp.health.gov/sites/default/files/2019-09/Physical_Activity_Guidelines_2nd_edition.pdf

#CardioFitness #Fitness