In regards to cardio training, runing, biking, rowing, whatever…it’s not very hard at all.
There is a misconception that if you’re working out like crazy, sweating up a monsoon, and exhausted with every breath, you’re getting slimmer by the second.
Although you may be burning calories, it’s probably not the calories you want to burn.
Whether it’s staying healthy or looking good, you want to keep muscle and lose a reasonable amount of fat (btw – you need fat, just not too much of it!).
When you exercise, your body uses two types of fuel sources, carbohydrates and fats. And depending on the intensity, you’ll either burn exclusively one or the other, or a combination.
The “sweet” spot is the spot where you’re primarily burning fat. The spot, or level, is commonly called your Zone 2 and scientifically known as just under your Lactic Acid Threshold.
Exercise physiologists divide your efforts into 5 or 6 zones (depending on who you talk to), and they are based on metrics of your blood lactate, which translates to a certain heart rate range.
Basically what they have been able to do is see at what levels (heart rate range) your body transitions through burning the various types of fuels, most fat/some carbs, some fat/some carbs, mostly carbs/some fat, all carbs, etc.
Zone 2 is where your body is burning the maximum amount of fat. It usually feels like about 60-70% of your maximum effort. See what I men about “not very hard”?
Zone 2’s benefits don’t stop with fat burning – it’s also nown to improve metabolic syndrome, type 2 diabetes, heart disease, have neuroprotective effects, and be less suppressive to the immune system.
I just had my Zone 2 tested through blood lactate testing. I jumped on a treadmill, they started me walking, then running, and would test my blood lactate at various levels. The data showed when I was in Zone 2 my heart rate was between 111-120 bpm. If I keep my heart rate within those ranges when doing cardio, I’ll burn the most fat.
If you can’t find someone to test you, you can estimate by using this equation 208-(0.7 x your age). This number will be your maximum heart rate (Zone 5 or 6), then multiply that by 0.6 for the low range of your Zone 2 and 0.7 for your high end.
Mine would be:
Max heart rate – Zone 5 or Zone 6 training:
208 – (0.7 x 47) = 175.2
Low Range Zone 2:
175.2 x 0.6 = 106
High Range Zone 2:
175.2 x 0.7 = 122
The numbers came out pretty close.
Two important notes:
- you should exercise 60-90 minutes in Zone 2 to optimize the most fat burning, and
- if you’re diabetic or have cardiovasculat issues; your Zone 2 can be much lower, so it might be valuable to get tested accurately.
