View Full Version : What is cardio?

11-30-2002, 07:11 PM
I thought if I ran 5 miles in or anything in over like 35-40 minutes it would be cardio. But I just learned about heart rate and that cardio should have a lower heart rate. Is walking on a treadmill at 4-4.5 mph slow enough for cardio? I know my running is just for endurance for wrestling.

11-30-2002, 07:29 PM
I'm sorry but maybe I'm misunderstanding. Are you asking if you should have a slow heart rate during cardio?

11-30-2002, 08:10 PM
Such a philospher-like question.

I always thought cardi owas supposed to boost yo hrt rte.

11-30-2002, 08:13 PM
Originally posted by Lizzie
I'm sorry but maybe I'm misunderstanding. Are you asking if you should have a slow heart rate during cardio?

Yes, exactly

11-30-2002, 08:14 PM
Originally posted by Kcck
Such a philospher-like question.

I always thought cardi owas supposed to boost yo hrt rte.

me too

Thats where I got it from, I also heard this from a friend, that for cardio you shouldn't run as fast.


12-01-2002, 09:45 AM
Thought this might give a little insight. Found it on the Labrada web site.

High vs. Low Intensity Cardio
by Robert Brooks

Bodybuilders and those trying to shed as much body fat as possible continue to argue over the aerobic (cardio) issue. Which intensity is better, high intensity or low intensity?

Before moving to the pros and cons of high vs. low intensity, we have to define the word ‘intensity’. For exercise physiologists, intensity means the level of effort put forth during your aerobic session. This effort is most easily measured by the heart rate of the exerciser. The person who is exercising at a higher heart rate, say 65-70% of his maximum or higher, would be deemed working at a high level of intensity, while an individual working at a lower heart rate, roughly 60% or below, would be deemed lower intensity.

The debate can be framed simply: "Which level of intensity will help an individual lose the maximum amount of bodyweight?" The answer depends on your current level of fitness and percentage of body fat.

The Pro-Low Intensity Group Argues: Lower intensity burns more fat

This position has some merit. The human body burns mostly fat while at complete rest. While you sit there and read this article, you may not be burning up a heck of a lot of calories, but your body is relying on fat as fuel. Surprise! At rest, the body prefers to burn fat as fuel rather than carbohydrates or protein. The individual engaging in low intensity aerobic work will maintain his fat burning status. For example, walking – clearly a very low intensity form of aerobic exercise – allows the body to burn more calories than at rest. During low, and especially very low intensity aerobic exercise, the body remains in a fat burning mode, preferring to burn fat for fuel rather than rely on carbs or protein.

Labrada Bottom Line: Lower intensity aerobic work is a good way to burn fat – to keep your body in a ‘fat burning mode.’

Lower intensity burns less Protein

So the body burns fat at rest, and lower intensity aerobic work helps the body burn calories. This encourages your body to remain in a fat burning zone, where fat remains the choice source of fuel. As the level of aerobic intensity increases, the body begins to burn a little bit less fat, and increasingly more carbohydrates and protein. The pro-low intensity group argues that aerobics performed at a lower level of intensity will coax the body to burn up extra calories while preventing the burning of carbs and protein.

Their understanding is that lower intensity aerobics is less catabolic (muscle wasting) than higher intensity aerobics. Their hope is that longer aerobic sessions – up to one hour at a time – will burn body fat exclusively without causing the body to tap into carbohydrates - and especially protein - as fuel. The minute the body starts delving into its supply of carbs and protein, the situation turns from one that is beneficial (where burning fat is the goal) to detrimental (where muscle comes into play as a source of fuel).

In other words, when the body starts to burn protein, you’re no longer benefiting from aerobic work. Some of the protein utilized comes from hard-earned muscle and even the smallest loss of muscle causes the metabolic rate to drop.

Labrada Bottom Line: Lower intensity aerobic work can prevent the loss of metabolically active muscle mass for fuel.

The Pro-High Intensity Group Argues: Higher intensity burns more Calories

This position also has merit. That’s because the higher you can get your heart rate, the more calories you’ll burn. For example, an person running for 30 minutes will increase his heart rate far more than he would if he had walked for 30 minutes. During that 30 minute run, the greater intensity will have burned up more total calories than the lower intensity 30-minute walk.

Labrada Bottom Line: The higher the heart rate, the more calories you burn.

It’s The Calories, Stupid

Those who follow the higher intensity school of thought often point out that total calories burned is the key for those who hope to tip the energy balance from positive to negative. Following the basic premise to weight loss that the body will lose weight and body fat when an individual expends and burns more calories than consumed (eaten), the higher intensity method of aerobics is often used to burn as many calories as possible.

Labrada Bottom Line: If you take in too many calories of any kind – from carbs, protein or fat - you’ll gain body fat. Period. The opposite holds true with aerobics: the more calories you burn, the more weight you will lose.

Which is best for you?

So both systems of aerobics sound pretty beneficial. Determining which is best for you may depend on your level of fitness and your level of body fat. Let me explain. While fat is the main source of fuel at rest, individuals with varying degrees of body fat burn different ratios of fat, carbs and protein. People who are overweight rely on a greater amount of sugar (carbs) for fuel at rest and during aerobic exercise.

Relying on sugar as fuel rather than large amounts of fat poses an important dilemma. "Sugar burners" often experience a quick plummet in blood sugar levels during aerobic exercise which leads to a feeling of weakness or dizziness, causing the suspension of the exercise. For this group, very low intensity aerobic exercise of a long duration is best solution. It can encourage or "re-program" a sugar burner’s body to begin to use more fat for fuel and less sugar during aerobic work. Lower intensity aerobic sessions also prevent drastic swings in blood sugar levels, allowing heavy-set individuals to continue to exercise.

If you are carrying a lot of body fat, stick with low to very low intensity aerobic work for longer periods of time. 50% of your maximum heart rate for 45-50 minutes will help the body begin to burn less sugar and more fat. That is, longer-duration aerobics at a lower level of intensity actually helps the body adjust and burn fat as a fuel source, rather than sugar. As you lean down, you can adjust your aerobics to a higher intensity and shorter duration.

Lean and muscular people burn not only more total calories at rest, but a greater percentage of those calories come from fat. For example, a top bodybuilder with very little body fat can expect to burn a heck of a lot more fat – and less sugar – during an aerobic session than an overweight person. Lean people tend to rely on fat as fuel while overweight people rely on a mix of fat and sugar. Since lean people already burn fat, the higher intensity method of cardio is best as it causes a greater calorie burn. Leaner folks don’t have to take into consideration "what’ they are burning – fat or sugar – because they tend to burn more fat than any other source of energy.

12-01-2002, 11:04 AM
Nice article. Goes over the basics very well but it doesn't really address the question.

Cardiovascular exercise is high intensity.
Aerobic exercise is low intensity.

One other thing that it misses is that there is an effect associated with all exercises that causes the metabolism of the body to be increased at rest following exercise. Most studies show that after cardiovascular exercise, the body remains at a higher metabolic rate for a longer period of time than aerobic exercise.

I've read also that cardiovascular exercise releases certain chemicals into the body which will reduce fat storage but I am not sure I believe it (never saw any evidence in the articles).

As far as endurance goes, running will increase your endurance much more than walking will. Runners can walk forever but walkers can't run very far.

12-01-2002, 11:10 AM
Thanks a lot Bradley, I printed the article out and read it, it describes the two different types of cardio and in the conclusion it tells you which one you should use. The conclusion was the must useful part. Makes me feel a lot better now that I know what kind of cardio is best for me.