What Train Low Means for Endurance Training?

The phrase “train low” is easy to misunderstand because it can sound like a specific diet or a rule to exercise without eating beforehand. In endurance training, however, the idea is broader than a single fasting routine. It refers to deliberately completing certain sessions with reduced carbohydrate availability as part of a planned nutrition strategy. How that lower availability is created can vary, which is why “train low” is better understood as a group of approaches rather than one fixed method.

Carbohydrate availability can be reduced in several ways, including fasted training, restricting carbohydrate during recovery, or completing a second session after glycogen has been lowered by an earlier workout. The emphasis is on selected sessions rather than every workout or all training .¹

One example is training after an overnight fast, a commonly studied form of low-carbohydrate-availability training. Other approaches create similar conditions through different timing of exercise and carbohydrate intake .¹

Although these strategies can influence metabolic responses to endurance training, research has not yet established one practical approach that consistently produces the best training or performance outcomes .¹

For endurance athletes, the important point is that “train low” describes a way of manipulating carbohydrate availability, not a requirement to restrict carbohydrate throughout training. Different versions can create different nutritional and training conditions, and those differences make it difficult to identify one protocol that is best for every situation. Research continues to examine where these strategies may be useful and how they can be incorporated without compromising the quality of training. For now, “train low” is best viewed as a flexible training-nutrition concept rather than a single formula to follow.