If you asked someone about what insulin is, you would probably get an answer similar to “doesn’t it have something to do with blood sugar?” or “doesn’t that have to do with diabetes?” If you asked someone involved in the fitness community, you might get a more technical answer about uptake of sugar in the muscles and muscle growth. Insulin plays a crucial role in how your muscles take in sugar for energy and how sugar is stored in your body. By understanding a little bit more about insulin, you can use the way your body already works to your advantage in reaching your health and fitness goals.
Insulin is a hormone that is made in your pancreas. Insulin helps to regulate your blood sugar by either storing the glucose (sugar) you take in when you eat carbohydrates for future use, or utilizing that glucose for immediate energy. Insulin is like the key that unlocks your body’s cells to let the glucose in. When you eat, your blood sugar rises, and this signals your pancreas to start releasing insulin. The insulin attaches to your body’s cells, which lets the cells know it’s okay to absorb the sugar. This sugar is used in your cells for energy! If you take in more glucose then your body needs, insulin helps your body store it in your liver for future use. If in a few hours, your body needs more energy, but you have not eaten anything, your blood sugar will begin to drop. When this happens, your liver is alerted to release some of it’s stored glucose to feed your cells.
Part of the reason people gain weight when they eat too much is because there is that extra glucose in the blood that the body does not need… this is stored for future use when your body needs energy, but if you aren’t expending enough energy to signal your body that you need more, the glucose is never released. Instead, it is stored as fat. This is why weight loss is a combination of controlled intake and controlled output.
Insulin plays a key role in muscle development, too. When you eat and insulin is released, glucose enters your muscle cells, which gives your muscles more energy to lift weights, run, walk, bend, and stretch. It also dilates your blood vessels, allowing more blood flow to your muscles, which allows more nutrients into your muscles. This is why you often see competitors eating simple carbs on show day, or athletes eating simple carbs before a game. Simple carbs are easy to digest and the glucose from them enters your blood stream quickly. This gives you a boost of energy and signals your pancreas to release insulin and the glucose is taken up in your cells. Because your muscles have taken in all that glucose, they appear more full and prominent and they have energy to move. Since your blood vessels also dilate with the increased insulin, you also appear more vascular.
So how can you use all of this information to your advantage? You can plan your food choices around the times you are most active. By eating complex carbs, which are slow to digest, throughout the day you keep your blood glucose levels relatively stable. The glucose from complex carbs is released over time; instead of the big burst of glucose your get with simple carbs. Because glucose never really “spikes”, your insulin level is also stable throughout the day. This means your body is going to resort to that stored glucose for energy. When you know you are going to be physically active, like before a lift or run, it’s good to eat simple carbs. This creates that blood sugar spike that results in increased insulin release. The insulin opens up your cells and that glucose you just took in is used for energy, instead of being stored. This allows your muscles to get the nutrients they need to work and grow and prevents fat storage.
If you tailor your meals around your activity, you can help your muscles grow faster and prevent the storage of extra fat. Now, doing this is not mandatory for fat loss… if you are at a caloric deficit, you are going to lose weight. However, by knowing more about how your body works, you can reach your goals more efficiently!
Photo by: Eric Wainwright. 2016. Wainwright Images.