View Full Version : Cardio Question: 65% vs. 80% HR and fat-burning

07-29-2007, 06:38 PM
I just started to consistently do cardio workouts. I ride the bike 30 minutes a day. Right now, I ride with a heart-rate of 160 beats-per-minute, my 80% max heart rate. The machine says that 65% max heart rate, or 130 beats-per-minute, is the fat-burn zone whereas the 80% max heart rate is the cardio zone. Can you burn as much, or more fat, given the same amount of workout time, @ 80% vs. 65%? Thanks in advance for answers.

07-29-2007, 11:25 PM
You're doing fine with the 80 % max heart rate.

Forget about the fat-burning zone. According to that theory, your body burns more fat than carbohydrates at low intensities.

This is true, but your goal is to burn calories and during your workout, it doesn't matter where those calories come from.

Your muscles stock a type of fuel called glycogen for ready access during exercise. After a workout, your muscles replace the glycogen they burned during exercise.

To enable this process, the body shuts off carbohydrate burning, shuttling dietary carbohydrate to your muscles, where it's converted to glycogen. your body still needs fuel for energy, so it switches to burning fat.

So don't worry about the type of fuel you're burning during your workout. Just burn it!!

High intensity workouts burn more calories during and after exercise than low intensity workouts.

If you want more bang for the buck, try high intensity interval training.

After 5 minutes warm up, ride your bike at level 10 (120 RPM) for 30 seconds, then ride your bike at level 2 (80 rpm) for 60 seconds. Repeat 10-15 times. Then cool down for 5 minutes.

07-30-2007, 12:16 AM
^^^^ i agree. don't worry about all that stuff. Also after you've been riding for a considerable time (months), your working hr will probably decrease into that 65% zone anyway.