High or Low Intensity for Cardio?

Have you ever looked at the chart on the cardio equipment that has the different training zones?  You’ll see a range for endurance, one for fat burning, and one for whatever....  Why is it that the fat burning zone requires less intensity than the aerobic capacity training zone?

The number is based on percentage.  In other words, training at a less intense pace, you will burn more fat - percentage wise - than training at a higher intensity.  However, let’s break these numbers down. 

The following is a comparison of energy expenditure between 30-40 Minutes of Low-Intensity vs. High Intensity Exercise

Low intensity:

Calories burned – 200

% Fat calories – 50%

Total Fat Calories-100

% of Carbohydrate calories-50%

Total Carb calories – 100

Calories per minute-6.67

High intensity:

Calories burned – 400

% Fat calories – 30%

Total Fat Calories-120

% of Carbohydrate calories-70%

Total Carb calories – 280

Calories per minute-13.5

Tell me, which numbers would you prefer? 

The American College of Sports Medicine and U.S. Surgeon General suggest that a minimum of 30-60 minutes of moderate activity be performed most days of the week to reduce the risk of cardiovascular disease.

2008 Physical Activity Guidelines for Americans (DHHS)

• Adults, 18-64: should avoid inactivity. Some physical activity is better than none, and adults who participate in any amount of physical activity gain some health benefits.

• For substantial health benefits, adults should do at least 150 minutes a week of moderate-intensity, or 75 minutes a week of vigorous-intensity aerobic physical activity, or an equivalent combination of moderate- and vigorous-intensity aerobic activity.
• Aerobic activity should be performed in episodes of at least 10 minutes, and preferably, it should be spread throughout the week.
• For additional and more extensive health benefits, adults should increase aerobic physical activity to 300 minutes a week of moderate-intensity, or 150 minutes a week of vigorous-intensity aerobic physical activity, or an equivalent combination of moderate- and vigorous-intensity activity.
• Additional health benefits are gained by engaging in physical activity beyond this amount.
• Adults should also include muscle-strengthening activities that involve all major muscle groups on 2 or more days a week.