I have a cardio conundrum. I’m 32 at 174 pounds, and I have a goal of losing weight. Because I can no longer run, it’s been suggested that I walk briskly on the treadmill at a high incline. I tried this today on the fat-burn setting, but the machine kept re-setting the incline and pace to get my heart rate in the “fat-burning zone” for my age and weight class. I continued the workout for 30 minutes, but I barely broke a sweat and didn’t feel like I worked out at all. I desperately wanted to return to the high incline and brisk pace, but I figured the machine knew what it was doing.
Should I stick with what the machine dictates?
Machines often target two different zones: Fat-burning and cardio.
The cardio zone programs are higher in intensity while the fat-burning zone programs are lower in intensity. When in the fat-burning zone, you burn fewer calories – but the idea is that a higher percent of those calories come from fat. Hence the name. When in the cardio zone, you burn a greater total number of calories.
Sounds like you should continue to work in the fat-burning zone? No. Consider the chart below which represents a 130 pound woman:
Even with a smaller percentage of calories coming from fat, you still burn more fat in the cardio zone.
But really, there’s a fundamental issue with relying on the treadmill to determine your “zone.” Fitness machines use a very simple formula to calculate your target heart rate involving only your age and weight. It doesn’t take into consideration your individuality – and the host of other relevant variables. The result is an overly generalized heart rate which usually isn’t accurate.
If you’re comfortable working out, I’d encourage you to think outside the treadmill’s zones and develop your own cardio routine that leaves you hot and sweaty. And, if you have issues running, it need not involve the treadmill.
Intervals are a great way to burn fat and they can be performed on many different types of cardio machines. I’d recommend trying intervals on a rowing machine. Row at a moderate pace for 90 seconds – and then switch to a sprint pace for 60 seconds. Do this for 15 minutes and you’ll be soaked in sweat. And, you’ll have boosted your metabolism.
You can also incorporate gut-busting intervals into strength training by moving between various exercises at differing speeds.
The bottom line: The zones on cardio machines are misleading and often inaccurate. Don’t give them more credit than they deserve – and certainly don’t base your weight loss program on their calculations.
P.S. If you have a fitness question for Davey Wavey, send it on over!