How Much Cardio Do I Need?

( – During a recent study, a group of over 40,000 business professionals was asked whether or not they could burn fat by only doing weight training.

About 85% responded that strength training alone was a sufficient way to burn fat.

This is not the correct answer – while yes, increasing lean muscle mass is a vital step in maintaining a healthy, calorie-burning metabolism, there is no way to avoid getting in some cardio if you want to burn fat (and help keep your cardiovascular system strong).

But this answer inevitably leads to yet another popular question: exactly how much cardio do you even have to do?

Q: I’ve read so much conflicting information about just how much cardio I need, and exactly how hard my heart needs to be working to meet my goals. Now I’m confused. Help!

A: Cardiovascular endurance, or aerobic endurance, is a vital component of a complete fitness program. This training makes the heart (cardio), lungs, and system of blood vessels and capillaries (vascular) transport nutrients more efficiently. Knowing how much cardio you need starts with a basic understanding of what these systems do for the body.

A well-trained heart will pump more blood in a single stroke than a poorly trained heart. So let’s suppose your resting heart rate (RHR) is 78 bpm. That means your heart beats 75 times in a minute to move a certain amount of blood. Your neighbor, Fitt Trainer, has a RHR of 68 bpm. That means his heart beats 10 times less in a minute to move the same amount of blood. This efficiency of moving blood with fewer strokes is one of the benefits of cardiovascular training.

A second benefit is the greater exchange of fuel for working muscles. Working muscles need important nutrients like oxygen and glucose in order to perform necessary tasks. A stronger heart will not only beat fewer times in a minute but, as a result of cardio training, will move a greater volume of blood with each stroke. So when you are exercising, more nutrients reach the muscles and the heart doesn’t need to beat as many times.

How Do We Get To A Better Cardio Workout?

There are four essential keys to effective cardio training:

Mode. Which exercises are you doing? That is up to you. Choose rhythmic activities like walking, running, cycling, stepping or cardio equipment. Select an activity that will keep you interested and feel free to change it as often as you like.

Intensity. How hard (or easy) is the activity? Knowing your predicted maximum heart rate (220-age) coupled with the Ratings of Perceived Exertion is a great place to start.

Let’s Take a 38 year old man and name him Charles. For Charles, this max would be 182bpm, and his or her heart rate should not exceed this limit. A more reliable formula is the Karvonen Formula, which determines a target heart rate zone to maintain for cardio endurance.

Let’s look at Charles again, with a RHR of 68pbm, and use the Karvonen Formula to determine the correct THRZ.

Training Heart Rate= Maximum heart rate – resting heart rate x desired intensity (50% -85%) + resting heart rate.

Basic Formula

220-38 (age)= 182 MHR
182- 68 (RHR) x .50 + 68=
114 x .50 + 68=
57 + 68 = 125pbm

Basic Formula (as applied to Charles)

182 – 68 x .85 + 68=
114 x .85 + 68 =