Question – A follow-up, if I may. Why does heart rate matter so much? Am I right, do I have to choose between getting fit or losing weight?
It’s not easy to figure out the answer because different sources tell you different things depending on what the source believes is more important for scientific, medical or profitable reasons.
Why does heart rate matter? In yesterday’s blog I used the analogy of a car, and it works for this explanation too. Let’s say your body is a hybrid car that burns gas (sugar) and electricity (fat) to move. The harder your heart beats, the more your body burns sugar. The less fit you are the more your body reaches for sugar to be sure you can get moving. If you’re like me, your body has been trained by decades of sedentary sitting and eons of evolution to burn the sugar first. Tomorrow we could starve, save the fat. So when you first start out on a fitness program your heart rate goes through the roof, your body burns sugar out of your bloodstream then various other sources until your legs wobble, your eyes see double and every nerve screams stop!!
That’s why people who took up Nova’s Marathon training challenge got incredibly fit, but only one participant lost weight. That participant restricted her calories and tempered her workouts to keep her heart rate lower. She burned fat and sugar—used both parts of the engine.
Activity that triggers sugar burning is essential to your cardio fitness. It’s what will let you climb a hill, chase a toddler, power-walk when you’re late to a meeting and not arrive out of breath. It’s important. As your cardio fitness improves, your body begins to use both sides of the engine to give you endurance, but if your body is resistant to ever using fat (true of many slow metabolism and sedentary people) it will always lean on sugar. You’ll have a heart like a horse, but you’ll have to keep filling the tank to keep the car moving; calorie intake will rise to match the amount of exercise.
If your goal is to lose weight as well (and I say “as well” because losing weight without becoming fit is an ultimately failing and unhealthy strategy), you can’t always be burning sugar. You have to get the engine to switch off the reliance on sugar burning in favor of fat burning (which breaks down into a number of things, including sugar). That’s why walking is such a great place to start on a fitness routine. Walking at a pace that leaves you just slightly out of breath is the zone. Over time (as discussed in the previous blog) you have to walk faster and faster, carry weight, etc., to get slightly out of breath. This activity doesn’t throw your body into a panic. Instead your body is trained to realize there’s plenty of time to burn fat for energy, and saves the sugar in case you decide to do something truly strenuous. But if that’s the only activity you do, your cardio fitness doesn’t improve. A power-walk because you’re late will leave you shaky and breathless.
For me, the key was combining both activity levels. I started my workouts slower, getting the switch to flip over to the electric source. After my body had hopefully started burning fat for fuel, I’d do something that sped up my heart rate, and burn sugar—but hopefully, fat would go right on being burned too, since my body had already triggered that process. Then I’d slow down again, recover my heart rate, and repeat the cycle.
When I took up running I began with walking for 3 minutes, then running for 1, repeating for the length of the workout. My most vigorous exercise level traded off 1 minute of each, so 30 minutes was half running, half walking. If running weren’t so hard on my bones and joints I would be sticking with it and not in search of a new activity, but a desire to have ankles that work when I’m 80 has nixed running. Hiking with some weight, on hills, is something I’m trying. Up the hill for cardio, down the hill to burn fat.
I hope that analogy helps. If you want to learn more about the organic chemistry of what happens when you exercise, I really recommend Covert Bailey’s books and videos. He’s retired, but his science is still sound. I haven’t read his Fit or Fat Woman, but it seems like it might be a logical place to start if you really want to understand your “hybrid.”
One last thing, dear reader—feel free to make a comment on my blog with any information you feel like sharing. Others may learn from your experience and be willing to share their experience with you.
Photo above was taken on the Dipsea Trail at Muir Redwood National Monument.