As much as I would’ve liked to title this article “How Not to Die,” I realize you could be the strongest, fastest-walkin

Insulin is knocking at the door, but eventually, the cells stop letting it in. Then, insulin has to knock louder and louder (meaning the pancreas makes more insulin to get to the cells to respond).,Metabolic flexibility is how well you can move back and forth between the two fuel sources. The good news is you can use the crossover effect to teach your body to burn more fat. Here’s how:,If you’re going to spend your hard-earned money or experiment with different nutritional strategies, you might as well know what science says are the strongest predictors of living to ripe old age. What’s most promising is you can improve any one of these without medication, surgery, or genetic intervention.,Every time you eat something, your body will do one of two things with those calories. It will either burn them for energy or store them for later use. Excess carbs are stored as glycogen (which your brain and muscles use for quick energy) or fat if your glycogen stores are full. Excess fat is stored as fat tissue.,Metabolic flexibility’s formal definition is the ability of an organism to respond or adapt according to changes in metabolic or energy demand, as well as the prevailing conditions or activity. That’s a lot of scientific speak to say metabolic flexibility is how well your body can switch from using carbohydrates to fats for energy depending on what you’re asking from it at the moment (i.e., working, exercising, sleeping).,You may have heard the term metabolic flexibility recently. The concept isn’t new, but the idea has gained more traction on popular websites, as being metabolically flexible is becoming a key marker of health.,Insulin is the body’s main fuel selector switch and the key to understanding what happens when metabolic flexibility goes south. Insulin is a hormone that promotes the absorption of glucose from the blood into the liver, fat, and skeletal muscle cells.,When someone is metabolically inflexible, they have a hard time burning stored body fat and can become insulin resistant. In fact, metabolic inflexibility plays a role in various diseases. I’ll explain why this happens and what you can do to teach your body to burn more stored body fat throughout your day.,Think about it this way. When you eat, insulin levels go up. When you’re fasted — meaning a period without eating (sleeping counts), your insulin levels go down. Here are the key points to remember:,I’ve been watching The Vow, an HBO docuseries about Nxivm (pronounced Nexium). Nxivm is… well, it’s a cult. But it was also a multilevel marketing company in the nebulous world of self-improvement. Participants were lured in by the notion of attaining a big life and told they needed to get rid of “limiting beliefs.” Over and over, members talked about aspiring to joy not as an occasional experience, but as a constant state of existence. Yet it seemed impossible for them to achieve that, no matter how many thousands of dollars they’d spend on courses.,You just read another post from In Fitness And In Health: a health and fitness community dedicated to sharing knowledge, lessons, and suggestions to living happier, healthier lives.,As a society, we’ve grown uncomfortable with hunger. We freak out. When the pantry is loaded with snacks, and it’s only a short walk to the kitchen, we find ourselves eating all day long.,A concept known as the crossover effect, shown in the graph below, demonstrates that our bodies switch from burning a higher percentage of fat to carbs at a certain level of intensity. Aerobic power is simply a measure of how hard your body is working. Zero is when you’re sitting or lying still; 100 is an all-out effort like a sprint.,If you don’t exercise, start. Exercise is the number one way to boost your metabolism and promote fat-burning. To continue the analogy, when you use your muscles during exercise, insulin doesn’t have to knock as loud for muscle cells to let it in. Exercise doesn’t have to be complicated. See #2. Also, add some components of resistance training a few days a week.,If you find you can’t go more than a few hours without eating before you start to feel awful, your body isn’t good at functioning on low insulin or burning body fat for energy. You may have to work to increase your time between meals slowly. You can start by cutting out snacks or extending the amount of time before eating breakfast in the morning.