Fat-Burning Training Zones Explained:
Are You Really Burning Fat When You Work Out?
One of our Over Fifty Fitness subscribers asked about fat-burning heart rate zones the other week. She was confused by the conflicting information on the internet and concerned that she wasn’t burning fat when her heart rate got too high.
You might have heard it discussed as Zone 1, 2, 3, 4 & 5 – with a strong push for Zone 2 heart rate (60% of your maximum heart rate).
The premise is that the lower the training heart rate is, the more fat you use as a fuel source.
Reading the chart above makes one think that the harder you work out, the less fat you use as a fuel source.
While it is true that the body burns fat as a fuel during low-intensity workouts, the fat-burning rate remains low, and you have to exercise longer to burn the same amount of calories you would at higher intensities.
Because it’s the total number of calories you burn that leads to the most weight (and fat) loss. In a high-intensity workout, although your body uses your carb/glycogen stores first for ‘fast energy’, it depletes the glycogen stores rapidly enough to force your body to tap on the fat storage. Additionally, the fat-burning zone (Zones 1 & 2) lacks an exercise afterburn effect. Research has proven that the harder you work out (Zones 4 and 5), the more afterburn you will experience. The afterburn effect, also known as excess post-exercise oxygen consumption (EPOC), is a physiological response to intense physical exercise, which means the body continues to burn more calories for several hours after the workout. It’s using more fuel to get your body back to homeostasis. If fat loss is your goal, the best way to burn fat is to work out at higher intensities — pushing your heart rate to around 70 percent or more of its maximum — while adjusting your diet to consume fewer calories. It’s worth noting that new exercisers or those with joint or medical issues may find working at 70 percent or more of their heart rate maximum for 5-6 days a week extremely fatiguing. So, my advice is to aim for 1-2 workouts a week in Zones 4 & 5, and 3-4 workouts a week in Zones 2 & 3. You won’t burn yourself out, your joints will continue to love you, and if you have modified your diet (because fat loss is 75% of what you eat – or don’t eat), you’ll burn that body fat. Deal? Deal!
Hi, I’m PJ Wren.
I’ve been working with people of all ages, all fitness abilities, and varying fitness goals for over two decades.
I’ve helped thousands of women over the years who are just like you, feel more energized, stronger, and more confident in their bodies. I turn gym goers and non-believers of getting fit at home into believers, with at-home workouts that will give you the results you want, no gym equipment or crazy diet required!
I’m passionate about women over 40 because I am over 40 myself.
I know what it feels like to be middle-aged, and what it’s like to have a hot flash while looking for my bloody reading glasses.
I’m honoured you choose me, in the HUGE ocean of fitness professionals, to help you get fit, get strong and get fierce.
I promise to only give it to ya straight while listening to what you want, and what you need.
ox PJ
