Understanding Cardio Endurance

CBN.com - Cardio/respiratory endurance is measured by how our heart and lungs respond to movement. There are three things that affect our cardio endurance: how often we exercise, how intensely we exercise, and how long each workout lasts. Every day that we set aside time for the specific purpose of getting our hearts pumping and filling our lungs with oxygen for a sustained period of time, we give our body the gift of these benefits:

1. Balanced “input”
2. Increased circulation
3. Strengthened heart and lung systems
4. Improved organ function
5. Improved outlook
6. Metabolized fat
7. Reduced stress
8. Improved appearance and sense of health and strength

As I have traveled around and spoken to women, I’ve been asked this question many times, “I’m a mom of several children. I run after them all day long. . . isn’t that exercise? And if so, why am I not losing weight?” This is an excellent question. There are two forms of cardio exercise: aerobic and anaerobic. Aerobic basically means “in the presence of oxygen” and anaerobic means “without the presence of oxygen.”

You may ask, “But aren’t we living, breathing creatures? Aren’t we always using oxygen to live?” Yes, this is true. As you sit and read this book, your body is at a certain level of homeostasis, meaning your input of oxygen and the demand you are placing on your body are in balance with each other. But if you were to get up and run up the stairs, your heart would start pumping, requiring an energy system to kick in. In this case your body would use the anaerobic energy system because your run upstairs required quick, accessible energy.  Your body stores a certain amount of energy in your muscles that is ready and available for quick movement. You may have recently eaten some carbohydrates, and your body has broken them down and stored them for when you will need them for quick use.

“Quick use” might mean running across the mall parking lot in the rain, rushing to the edge of your yard to keep your toddler from running into the street, or simply running after your children throughout the day.  Because these activities require only stints of energy, your body uses up the carbohydrates stored in your muscles. An important note here: This is often why we get the munchies throughout the day.  Our bodies want us to replenish those immediate energy stores. Where we go wrong is munching on empty calories that do little more than raise our blood sugar level to high buzz, only to allow us to crash and burn a little later in the day.  This is why I love a healthy snack bar. It provides protein, vitamins, and carbohydrates.

There is a great purpose for the anaerobic energy system. As you can see, there are countless scenarios each day that require quick movement. When you pick up around the house (low level of energy expended) and when you sprint across the parking lot (high level of energy expended for a short time), you will tap into your anaerobic system. There are many sports that are anaerobic in nature, like gymnastics, golf, short sprints in track-and-field, etc. Athletes who train in the anaerobic zone increase their threshold and their bodies recover much more efficiently than those who are not used to that kind of exercise.

I am writing to the average person who is not a trained athlete. In order to burn fat, work out longer, and recover in a more enjoyable fashion, you need to work out in the aerobic zone. In other words, you need a nice, slow warm-up that sends your body the message, “I am warming up slowly I am going to be out here for a while, and I need oxygen to help me.” Just a note about the warm up. When we start working out too quickly without a proper warm up, we are telling our bodies, “There is no way I can possibly sustain this pace for a long period of time so I probably won’t need any oxygen.” Our nervous system reads that message and suddenly we find ourselves breathing hard, needing to slow way down, and wondering if we are even cut out for this exercise thing.

Once you begin a nice, slow warm-up, you will feel your heart rate gradually increase. Give yourself time to get used to the increase and little by little increase your intensity until you are breathing hard but can still carry on a conversation. You will notice when you hit the “zone” that you will have arrived at a new level of balance or homeostasis. In other words, the demand you are putting on your body is met with the necessary oxygen to fulfill the task. Isn’t that amazing?

This is where it gets fun. It takes about 20 minutes of this kind of sustained exercise to efficiently burn fat. That’s why you want to work toward a cardio workout of about 45 minutes. This is not a hard and fast rule, but more of a generic scale. Each person is different, and each of us will access oxygen either quickly or slowly, depending on our current fitness level. The more fit you are, the quicker you will be able to warm up, access oxygen, and recover afterward. When you take the time to invest in your health, your body pays you back in great dividends.

Here are a few things to remember:

1. Exercise on an empty stomach or after a light snack.
2. Drink plenty of water before, during (if possible), and after exercise. Muscles work better when they are hydrated, and drinking water is like “internal” exercise.
3. Give yourself five to seven minutes to warm up.
4. Listen to your body and push just beyond what you feel like doing.
5. Give yourself five to ten minutes to cool down.
6. Always gently stretch after exercise.

Taken from Balance That Works When Life Doesn’t: Simple Steps to a Woman's Physical and Spiritual Health by Susie Larson; Copyright © 2005 by Susie Larson; Published by Harvest House Publishers, Eugene, OR; Used by Permission.