Fueling the Body

When athletes don't consume enough calories, their bodies go into crisis mode. This state, known as low energy availability, triggers a cascade of changes in hormone levels and metabolism.

Researchers set out to investigate whether carbohydrate intake plays a role in these changes. They studied 16 active adults who were given a controlled diet and exercise routine for four days. The participants were divided into two groups: one with low carbohydrate intake and the other with high carbohydrate intake. Both groups had restricted calorie intake, but the high carbohydrate group had more carbs to help their bodies function.

The results showed that both groups lost weight, but the high carbohydrate group had less of a drop in IGF-1, a hormone that regulates growth and development. Insulin, leptin, and testosterone levels also decreased less in the high carbohydrate group. This suggests that consuming more carbohydrates can help mitigate some of the negative effects of low energy availability on hormone levels.

The study also found that low energy availability caused the body to shift towards burning more fat for energy, but carbohydrate intake didn't affect this shift. However, high carbohydrate intake did help preserve the body's ability to produce lactate, a key energy source during intense exercise. This is important because it means that athletes who consume more carbohydrates may be able to perform better during intense activities.

The findings have implications for athletes and coaches looking to optimize performance while minimizing the risks associated with low energy availability.