What the heck is a fat burning “zone” anyway?
I am pretty sure most of us have spent many moments on a stationary bike, elliptical or stair climber staring at this colorful graph telling us where our heart rate needs to be for the “fat burning zone”.
Most graphs say 60-70% is where we need to sit in order to burn fat. This is true but there are other factors to consider. Age is not the only factor that effects fat burning. For instance you can have a 40 year old male beside a 25 year old male on a bike doing the same “fat burning zone”. If the 40 year old male is in better shape, he will need to be more at 75% of his max HR to be burning fat. And yes I know some very out of shape 20 somethings.
Age and fitness levels effect fat burning. It is really hard to tell what is actually best for each individual unless you do proper testing but that’s not happening for most of us.
We get caught up in this silly fat burning zone and not benefiting from other forms of training that can also burn fat and we also aren’t taking into consideration what is going on internally. If you are insulin resistance you can hang out in the fat burning zone until the cows come home and you won’t burn fat. If you want to focus on heart rate for training it is better to go by your resting HR, age, activity and goal.
This is where diet comes in. And where HIIT is a great option to lower glycogen levels. HIIT (High Intensity Interval Training) has been the talk of the fitness world for a long time now. It is actually funny how the people who need it won’t do it! Why? Because it takes them out of their comfort zone.
There are many factors that affect fat burning:
- You need oxygen to burn fat
- Slow twitch fibres have the most mitochondria and that is where carbs and fat are oxidized to make ATP (energy)
- Diet- if your insulin is constantly elevated and/or your life is full of stress, you will decrease the fat burning process.
- Age and Fitness levels
- FITT (frequency, intensity, time and type)
Factors that won’t increase fat burning:
- Spot reduction. You can do the inner thigh machine all day long but that will not get fat off your legs. You may end up with bigger legs! Work the same muscle over and over and it gets bigger!
- Calorie reduction
- 2 hours of cardio a day
- Fad diets
- Staying at the same intensity level and doing the same exercises
I could go on and on. Yes, the first thing to fat loss is to MOVE! But once you move, after a while your body adjusts, it gets better at what you are doing. This is because it loves to get back to homeostasis. Your body likes to be comfortable. But comfortable gets you very little results.
For any cardio you do there is aerobic and anaerobic. I am going to keep this simple: aerobic is with oxygen and anaerobic is without oxygen. You need oxygen to burn fat BUT with HIIT your body afterwards has to get back to normal oxygen levels and this process (EPOC) burns fat. Even at the time of intense training, fatty acids are still moved into the blood stream. Without oxygen the body can’t fully utilize fatty acids for fuel but they are in the blood. As you go back to normal activity, the body will use the fatty acids for fuel because your oxygen levels go back to normal. A great trick is doing 10 mins of HIIT with 20 mins of steady state cardio (70-75% of your max HR). You will automatically use those fatty acids as fuel.
Now when it comes to nutrition and hormone levels we have other issues. Again if your insulin and cortisol are constantly high, you reduce or stop fat burning. Insulin resistance comes from constantly having your insulin elevated and being inactive. If you are inactive you aren’t using the carb stores and it builds up in the body. This is where resistance comes in. You become more sensitive through activity but you may have to drop your carb intake at first in order to “balance out”. Focusing on having carbs around your workouts only.
You need progression your workouts all the time! This is key. If you are doing the same exercises at the same intensity, your fat burning will diminish. This is where the FITT principle comes in! You need to be consistent, increase intensity and/or increase time and change your routine.
When it comes to you cardio junkies, remember the more you do the less oxygen you consume which means the less fat you burn. You might as well do 20 mins of HIIT burn the same amount of calories with no muscle loss! Your body will burn carbs, then fat but once you aren’t getting enough oxygen in and your carb stores are running out, you will start breaking down muscle for fuel. Over time this not only has effect on skeletal muscle but also on your organs. They are muscles too.
If you are taking in carbs while you work out (sports drink) than this obviously will avoid muscle breakdown but won’t burn fat. So what is the point of doing more than 30 mins of cardio for fat burning? Well there isn’t a point. Unless you are training for an endurance sport. But again for a more conditioned individual they may be able to do more than 30 minutes and be fine.
Lifting weights is anaerobic BUT the more muscle you have the more metabolic active your body becomes making your body more efficient for burning fat. More muscle more fat burning! Your body will start requiring more energy at rest due to increase in muscle. Remember muscle is alive, fat is not! Increase your metabolism through weight lifting!
Reducing calories too low is not an option either. Your body requires a certain base level of calories to have proper organ function (basal metabolic rate). If you go below what your body needs to just survive, you end up with health issues. Not worth it! Determining a proper caloric intake based on fitness levels, metabolism, and activity is your best bet! 1-2lbs of weight loss per week is plenty and safe! You didn’t gain your weight overnight so you definitely won’t lose it over night!
So the bottom line:
- Do both steady state and HIIT. Or combine the two
- Always progress and change
- Eat for results!
- Stop trying to burn fat off a particular spot on your body with one exercise.
- Lift weights (increase muscle = fat burning)
- Be consistent
The process of burning fat is frustrating at times. What one person does may not be what another person needs to do. Some lose fat faster and some not so much! All you can do is aim for the best version of you. Don’t worry about what others are doing, worry about what you need to do! Everyone’s results will be different. Be patient and don’t give up that is what will give you the results you are looking for!