Muscles primarily consume energy through carbohydrates or fats
We want to find out what exercises burn more fats or carbohydrates.
For example, one the times that we burn the highest percentage or proportion of fats to carbs is at rest
Exercise intensity influecnese how our body consume fats compared to carbs. The chart below is from a male preparing for a marathon and so while the data won't be exactly the same between each person, the pattern generally is.
For example, in the chart above - If you're at a heartrate of 72 your total fat KCal burned per minute is 1.1. If you increase your heart rate to 127 the total fat KCal burned per minute is 4.7.
The "Fat" burning zone in the chart above is 138 (row 3).
The fat burning zone is dependent on many factors for a person though. Things such as:
All influence where the fat burning zone would be for a person.
That being said, the fat burning zone for most people is around Zone 2 in the endurance world. Zone 2 training would be this level on intensity where you are working hard but you are still able to have a conversation with somebody (known as the "talk test").
Is this the most effective way of burning fat though?
The total amount of calories burned is the more important thing to focus on rather than focusing on the specific ratio of fats to carbs or finding that perfect fat burning zone.
If the goal is to just lose fat then the focus should just be on total caloric expenditure.
STUDY:
They took 2 groups and divided one group into a low intensity group that was doing Zone 2 training (fat burning zone) and then another group was in the high intensity group.
What they had to account for in those situations was the amount of time because it's common knowledge that spending 1/2 hour in the high intensity zone will burn more calories than being in a lower intensity zone.
The study therefore increased the amount of exercise time for the Zone 2 group to match the total calories burned by the higher intensity group.
At the end of the study they found that both groups lost fat or weight at the same rate (there was not a significant difference between the 2 groups).
So the study showed that the more important factor was total caloric expenditure rather than which zone you are in.
Pros:
Cons:
Pros:
Our bodies can only store about 500g of carbs which is approx. 2000 calories (~8368 kilojoules). If we were just utilising carbs for an endurance race it would only last for about 1.5 hours.
Someone who is relatively fit can store upto 100,000 calories of fat (even more at higher body fat %). So if your body has spent a lot of time in Zone 2 due to training and you can mobilise fat it means you can spare some of those carbohydrates to utilise later on and last longer.
Yes, technically there is a fat burning zone but it's not necessarily the most important thing to focus on if your main goal is losing fat. The main thing to focus on is the overall caloric expenditure (total amount of calories burned).
How does this work though if you're still burning more carbohydrates than fats?
Excess Postexercise Oxygen Consumption
Unfortunately not, we don't have any control of this as it's primarily decided by genetics