The Fat Burning Zone – Is it Real?
The simple answer… Yes! Maintaining your heart rate between 60-70% of your estimated max heart rate during exercise will lead to burning more fat for energy. BUT – Staying in this zone may not lead to more body fat loss or even general weight loss than a slower paced exercise.
You will burn calories in your max heart rate zone but it may not actually affect your body composition. No matter how fast or slow it gets done, a target distance will burn close to the same amount of calories whether you are at your max heart rate during exercise or not. In other words, whether you are running a mile in 8 minutes or walking a mile in 18, you will burn very close to the same amount of calories. So the choice is really – would you rather workout for 8 minutes or 18 minutes?
Where Do the Calories You Burn Come From?
Both running and walking paces will burn about the same amount of calories if your target distance is the same. If you pick up the pace, your heart rate will be likely above 70% of your max. At this higher level of heart rate, muscle will utilize stored carbohydrates for energy instead of burning fat. Stored carbohydrates are perfered by the body during high paced exercise since fat is too slow to release the energy needed. Actual body fat loss happens after exercise, during recovery.
The used carbohydrates that were stored in the exercised muscle will need to be replenished. This process will break down fat into muscle glycogen (a form of carbohydrates) to replenish the muscles energy stores. No, you can not specify where this fat comes from. Lasting changes to body composition happens after exercise, during recovery.
The short of it is – if you want to lose fat you will need to burn calories (energy). The higher the heart rate, the faster your breathing rate, the more energy you will likely be expending. There is no specific pace or style of exercise that will elicit this response in everyone because we are all at a different training level. Pick an exercise that you can perform with safe form and maximize caloric expenditure. Running, jumping rope or even weight loaded squats are a great place to start.
Maximizing Fat Loss
Incorporating moderate to high intensity resistance training to your routine will help maximize fat loss. Muscles used during resistance training will utilize more carbohydrates for performance. This will cause the body to break down fat during recovery periods to replenish your carbohydrate stores. And don’t forget – your nutritional habits play a major role in fat and weight loss. Put in the effort and you will see results.