Cardio and burning fat

**juicepig** · 09-02-2006, 02:45 PM

How long should u be doing cardio until your body starts burning fat.. ex is it after 20 - 30 mins when your body starts burning fat?

**C_Bino** · 09-02-2006, 10:18 PM

Well its not a set time. It depends on intesity/heart rate and your own body really.
But there are 4 stages of energy consumtion your body goes through.
So they are:
1. ATP
2. Fast glycolysis
3. Slow gylcolisis
4. Fatty acid oxidation

So for example if you start sprinting your body will resort to these in the numerical order I listed. So for the first say 30 seconds it would use ATP stores until they are depelted than go on to the next etc.

But if you just walk for cardio for example your body doesnt need to use the top two and will just be in stages 3 and 4 mainly.

So for example a tennis player would remain mainly in stages 1 and 2, a marathon runner would spend the majority of their race in 3 and then 4.
Its why you burn out doing sets, you lose all your ATP stores and cant do anymore reps and your body wont go into stages 3 and 4 when weight training in most cases, thats why you need to replensih carbs after workouts.

So my suggestion for burning fat is to walk between 65 and 70% max heart rate to utilize fatty acid oxidation.

**sheb737** · 10-20-2006, 11:29 AM

this was a helpful post

Thanxs

**helium3** · 10-20-2006, 11:32 AM

Originally Posted by C_Bino

Well its not a set time. It depends on intesity/heart rate and your own body really.
But there are 4 stages of energy consumtion your body goes through.
So they are:
1. ATP
2. Fast glycolysis
3. Slow gylcolisis
4. Fatty acid oxidation

So for example if you start sprinting your body will resort to these in the numerical order I listed. So for the first say 30 seconds it would use ATP stores until they are depelted than go on to the next etc.

But if you just walk for cardio for example your body doesnt need to use the top two and will just be in stages 3 and 4 mainly.

So for example a tennis player would remain mainly in stages 1 and 2, a marathon runner would spend the majority of their race in 3 and then 4.
Its why you burn out doing sets, you lose all your ATP stores and cant do anymore reps and your body wont go into stages 3 and 4 when weight training in most cases, thats why you need to replensih carbs after workouts.

So my suggestion for burning fat is to walk between 65 and 70% max heart rate to utilize fatty acid oxidation.

nice job,couldnt a put it better myself.