Why is low intensity exercise better for weight loss than high intensity exercise?

The gyms I go to say 65% of you maximum heart rate for weight loss and 85% for cardiovascular fitness. Why is this true?

5 Responses to "Why is low intensity exercise better for weight loss than high intensity exercise?"

JavaJoe February 26, 2010 at 8:02 am

Honestly I don’t know, but it might have something to do with time spent.

You can go a lot longer at a slower pace than you can by going all out. Typically it takes 20 minutes of activity for you to enter the “fat burning zone”. My guess is you can stay there longer if you take it easier.
stig February 26, 2010 at 8:12 am

I’ve heard that you burn mostly carbs if you go up to 85% & you burn more fat at 65%.
david g February 26, 2010 at 9:06 am

Burning fat is best by slimming exercise burns of less cals than you think,ie a 5k fast run burns 300calories.less than a sandwhich.Slimming and exercise yes 2500 calories for a male.eat 1700 and you’ll lose two pounds per week
Whawha February 26, 2010 at 9:45 am

At 60% mhr you are doing little work, but just enough to trigger your fat burner on. At 80%mhr, your fat buner is on same as before, but that extra 20% is hard work for your heart and lungs, causeing them to get stronger. At 80% you use energy faster than your body can make it from fat, so that extra 20% takes energy from carbs, and other sources.

So at 80% you will burn the same amount of fat as 60% + the carbs in your blood and possibly proteins from your muscles.
Sherrie February 26, 2010 at 10:35 am

This is because when you get near your maximum heart rate your muscles require fast burning energy which can only come from glucose or protein (muscle) and not body fat.

We had a discussion on this once which will explain it:

http://www.apinchofhealth.com/forum/vbb/showthread.php?t=2051